SUSPENSION, A-bone question

[gowjob29]

Does anyone have any pics or have a diagram or something on a rear suspension of a model A with a buggy spring with split wishbones? My thanks in advance. Btw, Happy 4th to everyone! p.s. Mine is a 29 5 window with mustang (I think) rear.

[du$ty]

i can take some shots of how i did mine...gotta get my niegbors digi camera though...i did mine a little different but it works.

[stevenjerk]

yeah kartbreaker lets see some more pics of your roadster...thanks

[Dirty Dug]

I have that set up on my T roadster. I just noticed yesterday, after 5000 miles, that there are cracks in the welds and a small amount of fluid leakage where the bones attach to the axle tubes. I'm runnning an 8"Ford rear end. The split bones cause alot of stress on the thin axle tubes. I know there have been previous discussions on the board about this issue and I'm now rethinking the whole thing. I'm not going to change the basic set up but I want to make sure when I fix it that it won't break again. Having the fixtures completely surround the axle tubes, I think,is critical to the success of this set up.

[av8]

Think about running a rear wishbone, made up of long rear radius rods ('35-'36) connected together with a front wishbone yoke. I know of several high-mileage hot rods running this scheme with Ford 8-inch rearends without even a hint of trouble.

[Dirty Dug]

Thanks AV8, that's good advise. I'd have to give up on the split wishbone look but I'd end up with a more reliable set up. There isn't any stress on the axle tubes using what you suggest. I wonder if Frank Mack had the same problem but maybe he never side slipped the clutch. How one drives with split wishbones on the rear, I'm sure, will effect reliability. PS Sorry if I hijacked the post.

[du$ty]

heres some bad drawings of what i got going down..

[du$ty]

for some stupid reason i cant post the drawings...even though i srank them way down..stupid computer..sorry

well hot damn it works... http://www.jalopyjournal.com/ubbthreads/images/graemlins/smile.gif

[**DONOTDELETE**]

Kartbreaker. Do your drawings kind of small. I do all my Booze the Dog ones at about 4 inches square or so. Then I scan them in at that size and attach them. Dont know how big your drawing is but thats what works for me. Just trying to help out!

[Dirty Dug]

I wonder if having the spring in front of the rear axle takes some of the stress off the axle housing?

[**DONOTDELETE**]

dirty dug....No, it doesn't. http://www.jalopyjournal.com/ubbthreads/images/graemlins/frown.gif

[Digger_Dave]

Hello to Mike and John.
Well, once again tradition (mistaken design) gets in the way of good engineering.
I just looked back in my "archives" and this subject has been "hashed" quite a few times.

Split wishbones solidly attached to axles is an open invitation to something breaking.
Av8's advise to leave the wishbones attached to a single point like Ford designed them is the ONLY way to go unless you follow some of S.J.'s ideas that he came up with.
S.J. - time to repost the excellent Autocad drawings you shared back a while ago.

[Mart]

I remember a real good side on shot of a Magoo built A roadster from years ago. It had triangulated bars that all converged at a single point at the back of the rear trans crossmember. The bars were bolted through a big rose joint (heim joint) anchored to the crossmember.
We replicated the setup but used a rubber bush when we built the Clockwork Orange roadster, about 20 years ago. It's a great setup, simple, geometrically correct, and other than the rubber bush or heim joint, no moving parts.
Mart.
In response to Dave's note below, here's the best pics I have at short notice, you can see the bars coming forward from the axle, towards the middle of the car. (Pics are hosted on martsrods.com)
M.
http://www.flatheadv8.freeserve.co.uk/or6.jpg
http://www.flatheadv8.freeserve.co.uk/or4.jpg
http://www.flatheadv8.freeserve.co.uk/or2.jpg

[Digger_Dave]

Mart, your design works very well. Maybe you can post some pictures.
I seem to remember seeing the setup one time.

[Dirty Dug]

SJFast- No, I didn't think spring location would make a difference. Kartbreaker's drawing looks like it would snap right apart. I know there are better alternatives but I sure like the look of split bones not to mention the $ I spent to have the suckers chromed. Any suggestions as to how to keep the look and perhaps add unseen members and perhaps a flexable connection for the bones?

[du$ty]

oh horseshit...driving an old hotrod is an open invatation to things breaking...lets see in the old day they melted coathangers and stickwelded shit and drove all over the damn place.if you build it up right and how i did it im not gonna have any problems with that.i see some what of a point ..but theres a reason i took my rearend to the best weld fab shop in town..so it would people have been running slit wish bones forever..and thats my two cents worth..

[Dirty Dug]

I had my rear end tig welded and straightened by one of the best. The axle tubes are very thin. The welds didn't fail it cracked the tube at the welds. Don't get me wrong, I'm not attacking you but rather looking for the best alternative. The set up I used is at least as good as your drawing but it failed. It's not a matter of too much horsepower either. My car might produce 125hp if I'm bragging.

[Mart]

Ok, kick this one about.
simple radius rod to each side of the axle, single point attachment to the axle, no attempt to control axle torque at this point. Use a rubber bush for comfort.
Make a single triangulated torque reaction bar, solidly mounted to the axle, positioned to the right of the diff, coming forward and mounted in a rubber bush to the X member or a crossmember. The forward mounting is approximately in line with the forward ends of the side radius rods.
Sideways location by transverse leaf or panhard rod.
The advantages of this is:
No twisting stresses in the axle as the car rolls.
Having the torque reaction member located to the right of the diff compensates for the imbalance caused by pinion torque and equalises the tyre bite during acceletration.
(Complex subject)
Mart.

[**DONOTDELETE**]

Here's what I think Mart is describing. I agree !

[**DONOTDELETE**]

With the above torque arm you can take oval tube wishbones and mount them split to the side but with pivots at BOTH ends as in this drawing. Ignore the torque tube on this drawing. Mount the spring ahead, over, or behind the axle. Above puts the least amount of stress on the torque arm.

[Dirty Dug]

Please explain the connection at the crossmember. That set up is similiar to what kept me awake last night.

[Mart]

That's it, SJ.
The side mounted radius rods on the green roadster are super cool. Early ford tapered tubing, chromed, would look great drilled too.

Dug, the mount to the crossmember only has to control torque. the side rods control fore and aft forces. The little link does away with having the pivots all in line.

In essence the rear suspension on my coupe was similar.

Mart.

[**DONOTDELETE**]

Male and female rod ends screwed together. One connects to the arm and the other to the tranny crossmember. 3/4" min...maybe even 1". Lugs on both sides of rod ends to create a shear connection.

[Dirty Dug]

Thanks SJ, I'll have to give that some thought. As a side note: The old cars that had split bones probably had a torque tube making the set up OK. Would that be a correct assumption? The configuation you suggest would take it's place.

[**DONOTDELETE**]

Nope....that would be the most "bound up" way it could be done.

[Dirty Dug]

OK, I get it. I'm still confused by the front connection. Some people call me slow.

[Lowlife]

The new Am.Rodder has a great article on Nelson Dupre's buildup of the frame for Lance Sorchik's B-400.Might not be what you're after,but I'm sure some here will find a little food for thought.

[Digger_Dave]

[ QUOTE ]
oh horseshit...driving an old hotrod is an open invatation to things breaking...lets see in the old day they melted coathangers and stickwelded shit and drove all over the damn place.if you build it up right and how i did it im not gonna have any problems with that.i see some what of a point ..but theres a reason i took my rearend to the best weld fab shop in town..so it would people have been running slit wish bones forever..and thats my two cents worth..

[/ QUOTE ]

Trouble is, it might might be me that you run into head on when that setup breaks off the axle.
The drawing you show (and I'll assume the ends of the wishbones are attached to the frame) in fact creates a torsion bar out of the rear axle. So driving on rough roads could fatigue the welds on the rear axle and cause them to break off.
Yeh, split bones have been used for years, (solidly attached to the axle) but that doesn't make them safe!

[Dirty Dug]

I don't think the car he's got that set up on has been driven yet. I think he'll find the same results I did once , or if, he gets it on the road.

[**DONOTDELETE**]

That design is totally off-topic. This whole thread has been about side-mounted bones. What I see would work after a fashion because the ends all have poly bushings that offer some "give" as the rear axle works cancelling some of the bind.. Of course, they will deteriorate from use and fail eventually.

If the "bones" are connected solidly to the axle housings, I fail to see what the two top arms are even accomplishing.... http://www.jalopyjournal.com/ubbthreads/images/graemlins/confused.gif

[Dirty Dug]

I was refering to kartbreakers sketch. That other deal doesn't make any sense to me at all. Ignorance is trying something you're not sure will work, stupidity is trying it again after it fails. I try only to be ignorant.

[du$ty]

well i dont plan on being in canada anytime...so as long as you dont come to texas you'll be alright. http://www.jalopyjournal.com/ubbthreads/images/graemlins/laugh.gif
i think the mighty 215 six im running is not goona pop anything up..the post was about spitwishbone ways to set up on a model a frame..i showed a way i did mine.and again plenty of people drive with split wishbones...some even drill them out... http://www.jalopyjournal.com/ubbthreads/images/graemlins/shocked.gifoh my and have zip for problems.
i dont have airbags in my t either.

[Mart]

I'll stick my oar in again, here's a couple of observations.
I once ran a sort of pro street Thames 3ooE van with Alston non-parallel 4 bars, and with the narrow axle, I didn't have a problem with axle twist or fatigue, the problem was that the inside wheel would want to lift as the body rolled.
Re the photo from the magazine: I afree with sj, the radius rods should not be solidly attached to the axle. The bars would tend to bend before the axle twisted or fatigued though. BUT I don't like that design, my coupe had a very similar setup, and without a pabhard rod, the slight sway in the shackles lets the axle steer, rotating around the forward attachment points (or the theoretical convergence point) of the radius rods. This can effect high speed stability. My coupe had a problem with this, and I reckon it was the rear suspension that was causing it.
I would modify the design shown by running the lower rods parallel, either outside or inside the frame. The car could still swing slightly on the shackles, but at least the axle would remain straight across the frame.
In SJ's diagram showing the triangular single torque reaction bar, it is feasible to run just the top part, as a single bar, as in the magazine photo, as long as the side rods are mounted kinda low. There is a slight bending force applied to the axle, but it's pretty strong, and would be ok.
All my observations assume mild motors and street usage, wild horsepower lumps and dragstrip usage require specialised approaches.
Mart. (Mr bloody Limey know-it-all)

[Dirty Dug]

Kartbreaker, Please let us know how your split wishbones hold up once you get on the road.

[HotRodMicky]

Why don't you use heay-duty Tie rod end as on a split front wishbone.Add one "Torsin Bar as Mart described wiht ruber mount at one side and a heim joint on the other and you are fine.
Michael

[burndup]

So, what I can distill off of this conversation is:

The best rear suspension is a 4-bar setup, but the better you hide the fact that it really is a 4-bar, the cooler it becomes ? Or just stick with stock...

Is that what I'm hearin? http://www.jalopyjournal.com/ubbthreads/images/graemlins/smile.gif

Later,
J

[Dirty Dug]

That's what I gather. I think I'm just going to scrap the split bones this fall and fab up a four bar, won't be able to see it anyway plus it kinda goes with the vega box. Just hoping I can limp through the summer but I won't be driving to Bonneville.

[Mart]

Burnedup:
4 bar best?
I dunno.
My guess is that potentially 3 bars is better, you just have to overcome the idea that something is missing. If the two lower arms are parallel to the sides of the chassis, and fixed to the axle below the axle tube, and kinda level with the road, and the single top bar is mounted to the right of the diff, attached high up on the casing, and slopes down so the front is lower, then some benefit is gained.
It doesn't have to be complicated.
Mart.
PS: Gowjob29, you getting all this???
PPS: Just so there's no misunderstanding, "fixed to the axle" does not mean solidly, it means via a bush or spherical joint. In fact all three bars described above have bushes at each end.
M.

[Digger_Dave]

I think it's time to review whats been discussed here.
Ford used "bones" originally to keep the front and rear axles in their proper positions.
When "rodders" started to modify the frames and drop the bodies, the bones got in the way.
So the "quick and dirty solution" was to "split" them and move the ends of the wishbones out to the frame.

The technical problem was, now there was two "levers" that tried to twist the axle when the frame twisted.

The origin of 4 bars allowed up and down movement of the axle on either side without creating a binding action on the axle. But not everyone likes "the look."

If you examine S.J.'s drawings closely you'll see that the out side "bones" can pivot BOTH at the frame AND the axle. The centre "tourque" arm keeps the axle from "rotating." (thats what the original tourque tube was for on early Fords)

I'm not trying to say that split wishbones are WRONG; just that if you keep the original bones SOLIDLY attached to the axle
you set up some serious strain at the axle and the frame.

[burndup]

"The centre "tourque" arm keeps the axle from "rotating." (thats what the original tourque tube was for on early Fords)


"I'm not trying to say that split wishbones are WRONG; just that if you keep the original bones SOLIDLY attached to the axle
you set up some serious strain at the axle and the frame."



AHHHH YES... I fully understand and have mental tranquility of the "3 bar." Badass and simple.

[Hackerbilt]

Drag race ladder bar theory doesn't relate to splitting wishbones very well...
Ladders are usually only around 32-34 inches long, attached to the housing by full 360 degree double shear plates and use large, low pressure drag slicks which conform to the surface thus limiting the binding forces to the axle.
A ladder bar is designed like a truss...it will not fail due to any sensible load a car will see due to the triangle shape it has.

Wishbones, on the other hand, are much longer...the attachment point does not surround the axle housing and there is no upper bar to handle the torque from acceleration or braking forces.
This allows the tabs that the bones are bolted to on the housing, to fatigue at the weld and also stresses the joint at the rear of the bones, sometimes allowing that to break off as well.

A stock Ford absorbed the braking and acceleration forces thru the torque tube (notice name) and the bones just handled the impacts of the individual tires against road hazards...nothing compared to what they experience in a Hot Rod as the primary axle location device.

I would use 36 type bones, angled to the center or mounted to a front wishbone yoke (AV8) or rubber bushed like a P&J ladderbar setup. The tabs for the axle could be made to completely surround the housing for fatigue strength or a torque arm could be attached to the top of the diff housing and run forward to attach to the forward end of one of the wishbones. That would take most of the strain off of the axle/wishbone attachment points and allow more actual torque control.

Making wishbone style 4 links would be easy, as previously stated...

I've noticed some people using the fragile later (48ish) bones, complete with stock rear forged ends (!), as the only attachment for the rear axle...with no additional torque control.
My opinion...SUICIDE.
With the possibility of taking a few others with you...

Bill

[lowsquire]

Im planning on running split rear bones,will now design a mount that encircles the axle shaft,thanks to this thread,
my question is,does the torque control arm have to run forward to an imaginary line between the wishbone front mounts on the frame?that would put it somewhere in my left hip,which might hurt.
So will running a shorter torque arm cause it to bind?considering it will be rubber bushed at the chassis end.dont plan on having a lot of suspension travel,maybe four inches.its in an A chassis modified roadster(buggy sprung).
I cant quite get it all visualised in my head due to a hangover. http://www.jalopyjournal.com/ubbthreads/images/graemlins/crazy.gif

[Elrod]

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2422373393

http://ebay3.ipixmedia.com/abc/M28/_EBAY_b44fa12fcbe8f4d4ee7cfcb3e45b8d39/i-6.JPG

[metalshapes]

i am using 36 split bones on my roadster its on the road for about 2 yaers now , no problems yet . kept them as long as possible , tie rod in front is in line with A pillar . a guy at the L A roadster show tried to tell me how wrong that is and it would break , but he could not tell me where it would break .all parts are still unpainted so i can check for cracks , like i have been since i started driving it .

[**DONOTDELETE**]

lowsquire...the length of the torque arm isn't critical as all components (torque arm, split bones, springs, etc.) work independently of each other. The rubber bushing at the front of that arm will be better than a rigid connection but I'd still recommend a double rod-end. That allows the arm to work side to side as well as forward and rearward while cancelling axle torque reactions.

[Digger_Dave]

S.J., I dug out the article from American Rodder. (the picture posted earlier)
The lower arms do have pivot (hinge) points on either side of the axle underneath.
So what was created is in fact a triangulated "four bar." The use of TWO top bars probably
was personal preference.

Still like your design the best.

[gowjob29]

Ahh man! I want to thank all you guys again. Hey Mart, I love your site and thanks for the input too. I'm trying to get all of it,lol. This is my biggest turn out on a post. Most of mine some how end up on page two before I have the time to check it,hehe. Thanks again everyone!

[Canuck]

Question for av8: Is any additional bracing required, ie from the top of the dif housing to the front of the wishbones to handle the torque of a mild SBC, when connecting some 35-36 radius rods in this fashion? Like the idea and have a yoke off http://www.jalopyjournal.com/ubbthreads/images/graemlins/confused.gif a 41 Merc. Was planning on using a couple of HD 4 bar ends spaced as close as possible.

[Smokin Joe]

So, why not use your split wishbones as the lower bars of a triangulated 4 bar setup. Make 2 upper bars that come from above and either side of the center section and out to the upper part of the frame (boxed of course) on the inside where it won't show. The (say 36) radius rods would show as they do on that green car above. The upper bars wouldn't be seen from the side as they'd connect on the inside of the frame. There must be a reason it won't work. I can't believe I'm the first to think of it, but I've never seen it done. Use the transverse A spring above the axle and fab up some shock mounts ala A-V8's book and call it done. Frame guys please tell me what I'm missing here. I was planning on doing this on a stock model-A frame kicked up frame hight in the rear. Only problem I see is raising the trunk floor so it clears the upper bars during suspension travel.

[Hackerbilt]

Well Joe, you'd have to destroy the 36 bones to make a proper 4 bar setup. I wouldn't do it to 36's...too valuable and strong as they sit. Use later bones with a bushing added to the rear to give proper freedom of movement to the suspension for a four link or brace the 36 bones at the rear with a gusset or a torque link and use them alone with the front pivots mounted close to the forward U-joint or, like AV8 mentioned, run a stock Ford front axle pivot ball setup, welded securely to the front of the rear bones, close to the U-joint to replicate the stock Ford geometry. That sounds like a really good idea and I'm going to use it as part of my system IF I have room. I have an axle locating idea that seems very workable AND I don't think its been done before! Naturally, once I do it this fall, it WILL be proven that EVERYBODY did it back in the Fifties!
Thats OK....
Not much left you can be first at! LOL

Bill

[**DONOTDELETE**]

Smokin Joe....That will work fine as long as the wishbones and the two top links can all pivot at both ends. It's similar to a Chevelle 4-link. For quiet and comfort you might want to consider using rubber or urethane bushings at the forward ends of the four arms. Mounting the Model A spring over the axle will eliminate extra loading on those arms too.

[metalshapes]

smokin , if my setup would fail or start to crack , than this is my plan B : weld a machined collar to the axle where the mounting flange for the 36 whishbone is now . machine another ( 2 piece ) collar that grabs the 1st one and also bolts to the 36 whishbone , same for both sides of the axle .that would locate the axle the same in every way but rotation . and to take up rotation i would put in a torque arm like whats in a late model camaro . but before i start to redesign my car i would like to talk to someone that actually seen one fail , not some guy thats repeating what he has heard from another guy who was working with 2nd hand information himself .

[Hackerbilt]

Actually...you just need to go back to the fourth post on this thread, Metalshapes!
His welds are tearing clear of the housing!

Bill

[metalshapes]

hacker , i know , i read that too , but it sounded to me like he cracked the axle , not the whishbone .

[Grumpy]

This may be off the beaten path some but, what's everyones take on a tri-angulated 4-bar set-up? was looking at a C.E. chassis yesterday with that setup on rear and a 4-bar on front. is this a good setup, bad? or just too modern? thanks for clearing this up for me

[Hackerbilt]

Well...yeah, I guess your right...
But its still failure caused by fully split wishbones putting too much stress on the welds/housing... http://www.jalopyjournal.com/ubbthreads/images/graemlins/confused.gif

Somebody here was having or had an issue with 36 bones cracking at the joint. Can't remember who... http://www.jalopyjournal.com/ubbthreads/images/graemlins/frown.gif

Cool little roadster you have!
Would you be willing to give out a few secrets on your handling setup?
ALWAYS interested in hearing about hard cornering buggy spring setups!!! http://www.jalopyjournal.com/ubbthreads/images/graemlins/smile.gif
I want to dust a few late models with my coupe and the chassis starts going together in the fall... In fact, I just ordered the replacement front rail sections from the local metal fab today.
I was gonna use tube but some HAMBers suggested this route...I'm always ready to listen to good advice!

Bill

[metalshapes]

thanks for the kind words bill . no real secrets on the 28 and ill tell you anything you would like to know .

[metalshapes]

well maybe one secret , its a unibody car

[Adam F]

Can anyone tell me what the story is with this rear end set up ( I' cant remember where I got the picture from).
It looks like 36 type bones with a bar joining the two?
Anyone have any clues on its purpose?

Adam F

[Hackerbilt]

Unibody! Hmmm...thats interesting!
Thought about doing that too as the coupe is to be sectioned and MAY need to have the floor dropped into the rails. I'm leaning away from that at the moment...hoping the floor drop won't be necessary. I might need that extra bit of room for the suspension I want to run. The mock up in the fall will tell the tale.
What did you do? Make a welded tube framework and add the panels later?
At the very least, my coupe will have a braced roll bar setup...for stiffness and safety. I want a front hoop as well...but again, mockup needed!

Adam...Thats different isn't it? Seems like it was done to absorb some of the torque reaction and spread it into the bones AHEAD of the wishbones welded joint and axle mounting lugs.
Is it a good idea? Could be... I think it might be best to just weld the top and bottom of the square tube and leave the verticals alone. Good place for cracks to start if it were welded completely. Still a fair bit of strain being passed on... Kinda hard to visualize where strain is being placed with that setup in various road conditions.
JYD 32 is a welder up on that stuff...hope he adds a comment.
Hope EVERYONE adds a comment! http://www.jalopyjournal.com/ubbthreads/images/graemlins/laugh.gif

A very interesting thread!

Bill

[du$ty]

adam..i think thats a kinda sway bar since it looks like hes running a 40s spring..and most of them had those...looks like he just applied that to the rod.

[C9]

Here's a bit of clever thinking that's going on an about 1700# T roadster with built flathead.

Welded to the axle is a ring with channel sides to retain the pivoting piece that bolts it on.
Installed when the axle ends were off.

The outer ring that bolts the split wishbone to the channel ring is two pieces with a step or overlap that is held together with a bolt at each end - 180 degrees apart.

The thinking is this will stop twist at the split wishbones - which are parallel with and outside the frame rails & connected with the larger (3/4") truck tie rod end.

Torque will be controlled by the short torque tube which is perhaps 30" long.

Looks like a viable deal to me and my only criticism is the moving rings are both made of steel and may wear fast.
The guy doing it doesn't think it will if kept lubed.

[C9]

Here's an overall view of the rear axle noted above.

[**DONOTDELETE**]

Excellent idea ! It may wear after a VERY LONG period of time but, as long as it's kept lubed, it is an idea that's superior to most setups I've seen. The only problem I see is, as the chassis rolls in a turn, it may try to put a slight twisting force in the side-mounted wishbones. Probably not enough to cause any long-term damage.

[C9]

I think the tie rod ends will allow body roll with no probs.
for the most part anyway, they do have a limit and the car does have transverse springs front and rear.
Not sure if they're going to do a sway bar or not, but a light duty one could be a good idea.

[**DONOTDELETE**]

C9....Assuming the side-mounted wishbones to be both mounted level, when the body rolls in either direction it tries to pull the axle in a forward direction. Unless the torque tube has a slip joint in it like the old Chevy ones, it will not allow the rear axle that forward movement. That's why I advocate a center-mounted torque arm with two spherical rod end bearings at the forward end. the rear can then follow the path(s) dictated by the wishbones without bind.

I agree that a light roll stabilizer bar should be used. http://www.jalopyjournal.com/ubbthreads/images/graemlins/smile.gif

[Elrod]

That ain't just a bar welded in between the wishbones. There is a large U bolt going around the "pinion" on the front side of the banjo. It's in essence tying the rear end back in to the equation in a third point.

Now, the wishbones are preventing the axle from turning side to side under the car (don't want artifical quadra-steer!) and the bar welded under there prevents the rear axle from rolling or buckling under


http://www.jalopyjournal.com/ubbthreads/image_uploads/104952-bottomof32.jpg

[Rocky]

Yews but you're still transfering all the rotational torque of the rear axle housing [under acceleration and deceleration] to the front of those poor wishbones. Hope the bones are thick-wall tubing.

[metalshapes]

adam , looks like the guy tried to beef it up a little after converting it to a open drive line . lets hope he didnt need to becourse he is putting the force on the side of an unsupported tube an then he does it again by welding that tube to the whishbones , check out the panhard bar mount , scary shit! c9 , that is cool , almost exactly what i was trying to discribe as my plan B . nicely done too .

[Mart]

Elrod, that setup is not the best.
The rods are still subject to severe bending stresses when you accelerate in 1st.
A simple torque rod from the front of one or both of the radius rods to the top of the diff would beef things up a treat.
the hotrodworks market such a device. http://www.hotrodworks.com/hrw4.jpg
Mart

[Smokin Joe]

Getting some good tech stuff here. Any more ideas?

[cornfieldrodder]

This threads timing is great for me, as I'm doin' the rear on the Quad Mod. The look of split rear bones is atractive, but the geometry is bad. Space becomes a problem in a low narrow car.
It helps to build a model for these kinds of things. Using a wooden dowell, 1/2 " dia or so, and some pieces of plywood with the dowell dia drilled into them cut to replicate the planned brackets, one can test a variety of ideas.
The tourque arm idea works OK, but the arm tends to twist, which may result in fatigue and failure. The part could be cheaply replaced as a maintainance item ,though. A 3 link with a common pivot point works very well too. Both systems have to fit between the seats in this case so the are not the best options. A 3 link with a Y shaped link at the top has potential if the room is available AND would allow for the split bones look. Alas, I have not the room.
The next test on my agenda is to sort of copy my old Austin Healey. Since the plan has been to use 1/4 eliptic springs, they can be used as two bars of a 4 link. The Ford radius rods can then be used as the upper links, using thier entire length for the look of split bones. The geometry may be no good, though, as the rear will rotate with the differing arcs, which would be quite a bit.
Does anyone have expeirience wit the Y link or the 1/4 eliptic/4 link with long radius rods? My models won't tell me what real word knowlege would about ride, and traction.
The Frank Mack car and maybe the Steve Grimes mod had solid mouned bones or raius rods. Does any one have good knowlege of those cars and the reliabilty of them?

[modernbeat]

I've got some ideas on split bones using a version of the "wristed arm" used on a lot of high lift Broncos. I'll draw it up tonight and post it.

Meanwhile, search the web for "Wristed Arm Bronco"

[Hackerbilt]

Hmmmm....I dunno Modernbeat!
I respect your opinion but that setup has issues...
High potential for wheel hop, DOUBLED torque loading for the solidly attached wishbone...
Do you intend to set it up as lockable, like the guys with the Bronco's are doing?
Actually, the Bronco system gives plenty of articulation as-is for a street driven vehicle. A little FUNKY on the axle attachment...but workable!

Ya know what would work? With no bad manners...good flex...no welded joint near the axle to fatigue and fail from torque loading etc...etc?

Land Rover(?) I beam control arms!

And as my brain twists...I see heavy wall wishbones, complete with TWO inline rubber bushings, (a small diameter front bushing paired with a larger rear would be best), at the rear attached to 360 degree double shear plates around the axle housing.
Done this way, bones COULD be run parallel to the frame without articulation issues...without fatigue issues and would still be able to control wheel hop to a fair degree.
Sorta like this...

Pic is crappy but you get the idea...
Small bushing at front of axle keeps the bone thick enough to be reliable. If more strength were needed, the bone could be braced with plate internally, before the bushing tubes are installed.
Parallel bones, with flex and strength!
What do ya think? Workable?

Bill

[**DONOTDELETE**]

cornfield rodder....The torque arm with double spherical rod ends does NOT twist at all !

[cornfieldrodder]

SJ,
Yeah, I figgered that out, my model used a common bolt for mounting. It was late and I wanted to save time so i could get to bed. Sorry for the miscalculation.
I like the idea of the soft mounted radius arms. Wonder if wheel hop or bushing fatigue would be a concern?

[Hackerbilt]

I don't think it would be Cornfield. Think of the beating a regular leaf spring bushing takes over its lifetime. Mercedes G wagon and some versions of Land Rover have been doing it like this for years!
Wishbone strength is the biggest concern I can think of. (The OEM builders use I beam like arms.)
Internal gusseting should solve that for all but the most powerful vehicles. Have to be damn powerful too, to bust the braced bone!

Bill

[metalshapes]

Hacker , that should work , where does the spring go ?

[Hackerbilt]

Depending on the axle used... the shear plate(s) could be designed with a spring mount built in.
Hmmm... might be an issue with a rear mounted spring constantly loading the bushings... Quality OEM suspension bushings would handle the stress OK,IMHO.
Naaa...shouldn't be a problem... those type bushings are used in leaf springs and see loads of weight ALL the time!

The bones could also be used to actually mount the spring...Like a 36 setup...That would work fine with no issues to speak of.
Top mounted spring should be no problem either.
Naturally, some early rears had the spring mounts in place already.
Anyone see anything I'm missing here?

Bill

[modernbeat]

Okay, here's what I was thinking of.

The first setup in the image is a modified version of the stalwart '36 design. I replaced the bolts that connect the arm to the axle with spherical bearings. Using two bearing in line with the arm keeps the axle from being "floppy" at the end of the arm like most Bronco Wristed Arms.

But, that '36 setup really concentrates the torque at the front conection point of the axle and threatens to bend or break the arm during heavy accelaration or braking.

So, I redesigned the attachment plate to line the attachment points up with the axle to lessen, but not eliminate the rotational stress. Then, I'd make the arms out of something very stout and twistable like a pair of straight Econoline I-beam front axles. Weld a gussett to the back end that sandwiches the spherical bearings and a heavy duty tie-rod end on the front.

To simplify it a little, bushings could be used to replace the "traditional" tie-rod end and the spherical bearings.

[metalshapes]

i think i would only use one soft bushing per bone , so the axle can only rotate a bit , and not move up and down .and then put the spring on the bone behind the axle . and the shocks on the axle

[Hackerbilt]

Hmmmm.... Looks like we're on the same track!

Can't see the sphericals working... Won't allow missalignment in the vertical plane. The main issue is to allow some movement up and down at the front end of the bone if its mounted to the rear axle...fully split.
The Bronco guys addressed it by hinging one arm at the axle. With two sphericals and two bolts on the axle end of each arm you won't get the hinge effect.
Rubber bushings have enough elasticity to flex over and over, in multiple directions, with no wear or noise. They give a built in hinge effect to the locators...without the looseness of an actual hinge!
Maybe a combo of a spherical and a bushing? Big bushing at the rear and a spherical at the front axle mount...with another bushing or a tierod end at the very front?
I dunno...I'm a bushing fan just for the durability!

Bill

[modernbeat]

I've seen this used on a few high-articulation trucks. It's a modified version of that slip joint version shown above.

This slip joint on a CAE front axle on Cotton Werksman's car prevented axle bind. The opposite wishbone was bolted rigidly to the front axle. The same setup could be used on a rear axle.

[Mart]

Unless I'm missing something, having a hairpin type radius rod attached to the axle with a bracket that is able to rotate would certainly do away with axle bind problems, but the radius rod could equally be just a single rod. Problem is, it would just look like something is missing. I think AV8 referred to Kent Fuller using a 3 bar setup on some dragster front ends.
Mart.

[**DONOTDELETE**]

ALL modern sprint cars use the 3-link design on the front axle. 2 on the right and a single on the left. The reason is when the chassis rolls to the right in a turn with a 4-link and a panhard bar, it lifts the left front wheel off the ground. This is NOT a desirable situation. It proves that the 4-link/panhard combo has a built-in bind. The street rod 4-link setups use urethane bushings to lessen that bind but it is still present. In fact, that bind acts as a roll stabilizer because it only allows a minimal amount of body roll before the bind kicks in.

[Hackerbilt]

Oooohhh.... I think I get you now Modern!
I didn't realize that you meant for one of the shear plate assembly's to mount like that...able to rotate around the housing!

The solid mounted bar would be transfering ALL the torque to the chassis...is that workable? Could cause some weight jacking...although with a long bar...I guess it would be controllable.
I wonder would it make the car dart under braking or acceleration? Wheel hop on the hinged side?

Still...Cotton Werksman had it on those 2 little Mod's so maybe it's a non-issue!
Have you ever seen it on the rear?

Actually...I might have!
I know Soni Honneger had a Mil Jeep with something like that only different. http://www.jalopyjournal.com/ubbthreads/images/graemlins/crazy.gif
Offset diff allowed him to build a "Y" shaped link that was mounted flat with a donut bushing at the frame and two regular bushings tabbed to the axle. That link controlled side to side movement and located that side of the axle, front to rear. On the side with the diff he had what was basicly a ladder bar to control torque and location...a donut bushing at the frame and reg bushings at the axle.
NO other links were necessary to control the axle! Two frame bushings held the whole front end. NO Panhard rod either! I THINK the rear was much the same. (Offset diff as well...)
Articulation is a much bigger issue for the 4x4's than for us... Our total would only be in the area of...8-10 inches???

I still like the 4 bushings myself. It's proven under some high dollar rides and it has no potential for metal to metal wear. Sure would be nice to have all that room in the middle of my chassis!
Sunken floor and lots of head room! Hmmmm......

Bill

[modernbeat]

Totally different track here....

How about adapting the SPRINGPLATES from a VW?

Don't use the torsion bars, just the locating arms. By using a sheet or two thinner peices of spring steel you can introduce bending in a single dimension and twisting to make up the reduction of track width relative to the frame when a single wheel is raised.

As a bonus, they can be used in a fairly short, compact area like the area behind the cockpit of a modified that's received a serious Z in the rear.

Don't want to use VW parts in your Ford? I don't blame you. Just use the principal instead. Make your own spring receivers for the axle and the front attachment point. You can use spherical bearings, urathane, tie-rod, heim-joint (which is just an adjustable length spherical bearing), etc...at the front.

Bonus number two. When used in a solid axle application, the spring plates natural resistance to twist acts as an anti-roll bar. Uses some of the same principals as the De-Dion axle.

The OEM looking VW stuff:
http://laudeman.com/bugimages/plate1.jpg

And a purpose built version - not to scale. The axle is on the left and the attachment to the frame is on the right. The gray bars are spring steel.

[metalshapes]

i saw the original , '59 Bocar X1 , ( the other cobra , cheeta type racecar ) is uses the whole rear susp. out of a bug , but , only as the lower links . it has 2 bars coming off the axle to make it into a short 4bar setup . must have workt good tough , is was very succesfull . i think that setup would be to wide for a fenderless hot rod

[Kevin Lee]

I'm jumping back to corfield's post here in regards to seat clearance with a torque arm, but who says the torque arm has to be on the top of the rear end? It'd work the same way hung off of the bottom. The forces for accelleration and braking would just be reversed. No problem.

I'm still in limbo for my trans and whether I have open or closed drive, but if I HAVE to go open - and I really dont want to, I'm using MILDLY split bones triangulated to intersect at the u-joint and a torque arm hung from the bottom of the banjo. Clearance smearance.

[Jalopy Banger]

This is also an untraditional way, Volvo PV 544 used this set up during the 60´s. A mild splitted "wishbone" attached to the rearend with rubberbushings and a U-bolt. Then the pinjon house is attached to the body and finally a panhardbar is there for sideway movement.
Simple,safe and ugly. Volvo even competed succesfully in rally with this car model. I can´t help it, but i would prefer to copy the old ideas, with all its bending and breaking. Now i´m runnin K-link on my 8 inch, don´t tell anyone...

[Hackerbilt]

I don't know about the torsion plates! Remember, you need twist AND some rotation flex at the axis of the rearend...
Like this...

[DrJ]

[ QUOTE ]
This is also an untraditional way, Volvo PV 544 used this set up during the 60´s. A mild splitted "wishbone" attached to the rearend with rubberbushings and a U-bolt. Then the pinjon house is attached to the body


[/ QUOTE ]

This would be by parts "3""5" but it's not real clear which one is on the rear end housing and whick is on the body..Is "3" mounted to the body and "5" to the axle?
Seems that unless the axle doesn't travel far (short travel tube shocks?) those short bars "4" would change the pinion angle greatly.

[Jalopy Banger]

DrJ- A close look in the manual showes that #3 is connected to the body and #5 to the rearend. What i can remember from a long time ago disambling of such a rearend the short bar ends (#4) were embedded in rubber bushing too. Well, Volvo didn´t use this on their later models, they went to a form of parallel fourlink and panhard bar.

[cornfieldrodder]

Grim, the torque arm mounted under the rear could cause a problem with wy plans for a rear cross member under the driveshaft. The rear of the frame is now only 9 inches from the ground. The idea sure is worth reconsidering the design, though. This is why I posted about using a torque tube with a modern GM trans a few months back. Ol' Henry solved these problems long ago.

[metalshapes]

VW's ? Volvos ? alright! you guys are openminded enough for furrin shit . look under an Alfa Romeo Alfetta . De dion rear susp. thin wall tubing with tapered tubes that make up a whishbone like an early ford , use that with a halibrand centresection and inboard finned buick drums as traditional as you would want it , in a Indy sort of way .

[Honest]

THIS IS A GREAT POST.........BTTT

[modernbeat]

Torque arm and VERY SHORT forward lower links. The only thing I could criticize on this setup is that the torque arm shackle (at the front of the arm) won't accept a lot of twist that occurs when one wheel is raised. Hell, they even mounted everything in double shear! Good Job!

FWIW, this is the same suspension setup used in late model Camaros except that instead of a shackle to provide give at the front of the torque arm, the stamped sheet metal arm slides back and forth through a bushing.

Snagged these pics off the Metalshapers.org galleries.

http://allshops.org/community/CommunityAlbum/9960115624921.jpg

http://allshops.org/community/CommunityAlbum/9990115624922.jpg

[modernbeat]

And a couple more of a Torque Arm. This one features an "L" shape to clear the back of the body and an adjustment at the bottom of the arm at the axle to adjust pinon angle.

I grabbed these from George Cathey's gallery. (http://allshops.org/cgi-bin/community/communityalbums.cgi?action=openalbum&albumid=99801 06978583&ownerid=9990082580986)


http://allshops.org/community/CommunityAlbum/9970115624921.jpg

http://allshops.org/community/CommunityAlbum/9980115624921.jpg

[Dirty Dug]

This has been great input. But let's get back to the subject of split wishbones. The original intention was for them to keep the car flat in corners, right? Well, how can we build a car with conventional split bones so they won't break anything, like beefing up the axle housing to take the stress. Come on you sages!

[**DONOTDELETE**]

dirty dug....copy the above torque arms (except make a more flexible front connection) and have pivots at both ends of your split 'bones. Also, mount them at the axle centerline, not below as shown in those two examples.

[metalshapes]

dirty , i cut my whishbones becourse my roadster is to low to have any suspension underneath . i thought that the build in swaybar effect was a draw back . thats why i kept them that long , so they bend easier .also a bonus is that the rails are narrower when you go farther to the front , so the bending/binding problem is not as bad , when the body leans in a corner .

[Mart]

Nice work there, Metalshaper.
Dug, as stated above, The strongly built torque arm as in the examples above is ideal when using split bones. The lower links on the above setups could easily be replaced by early ford parts mounted outside the rails, BUT the attachment to the axle must be flexible.
The forward attachment should include a shackle or twin heim joint to reduce bind.
But at the end of the day, we're not talking rock crawling max articulation 4-wheel drivers here, Suspension movement is rods is normally pretty limited so we can, er, BEND the rules.
Mart.