Technical Front suspension rebuild...problem...please help

I never did a side by side comparison of the batwings...I guess I shoulda...I will look at that...
The adjustable ends do seem a tad longer and that could definitely be a problem...I will measure the difference today...thanx!

 

The new ones are different...I used stainless to prevent rust...I confess that I did not do a side by side comparison...

 

Please post the final fix when you get it.

 

Surely nothing preventing a side by side comparison of the batwings right now is there? (Daily driver - driven possibly today or certainly yesterday? )

If the new batwings place the forward end of the 4 bars further back than before that will require shortening of the 4 bars to get back to the same place.

Are we sure the 4 bars are the same length? (ie top and bottom on the same side - they should be the same side to side too however). The fact that the adjuster on one seems to be rather more extended than the other seemingly suggests otherwise?

Also, there appears to be some rake in the chassis mounting point and this rake should mirror the rake in the batwings, otherwise the 4 bars wont be forming a parallelogram. Swapping the batwings for different ones might be affecting this. To the extent that the 4 bars aren't of equal length, or the bars not being parallel (eg different spacings between the chassis mounts and the new batwings) there will be some bind, but if minimal the poly bushes should accommodate.

Chris

 

As PWood said, start with just the main leaf. Support the frame at ride height with blocks or jacks so there is little load on the axle. You should be able to remove the bolts and adjust the bars. Then put the rest of the spring leaves in.

 

Here's how I would fix your current problem: Set the car on the ground, and disconnect the bars of one side at the frame. The other side's bars should hold the axle upright.

Adjust these too long bars a bit shorter. Maybe a half inch. Then reinstall. You will have a hard time shoving the axle around, and fitting the bolts back in place. Then do the same to the other side. Again it will be hard to shove around, but you will be getting closer.

Now you are probably in the ball park on the spring/wheelbase/alignment. It is just fine tuning from here. You can maybe do one bar at a time, but more than likely you will have to do both bars on one side at a time.

Since you changed the rear adjusters, and you said they are maybe longer than the originals, you might need to tap the threads deeper in those bars and slice a fraction of an inch off the bar. If you thread the adjuster all the way in and find you have no more room, you will realize this. Changing some parts will always affect the remaining parts. Such is hot rodding.

The standard caster for a straight axle car posted on the internet lately has been 7 degrees. But I have also seen guys say that is too much. When you are setting up your axle, you may find e different measurement is best for your situation. Driving the car will probably tell you if adjustments are needed.

I hopefully have given you a simple enough explanation of the process as I see it. I realize you are a beginner and have never done anything like this before.

 

The four bars only prevent the axle from moving front or back. The spring and perches hold the weight. When you lowered the car the longer bars pushed the axle forward and put the spring in a bind because the adjustable perch bolts were tight. If your crossmember has 7 degrees you probably didn't need the adj perches. With a properly adjusted 4 bar and the car on the ground you should be able to remove any 4 bar bolt without a bind. Trying to correct the caster with the 4 bars and non adjustable perches will put the front end in a bind and prematurely wear the bushings. PWood is right when setting up a new frame and alchemys method will come close, but undoing one side will still leave the axle and spring in a bind. If it make you nervous to put all the weight on the ground without the bars, go ahead and block the frame when the suspension is close full weight. It appears the adjusters might bottom out and you might have to cut the bars to shorten them. Or use non adjustable bar ends if the proper angle is available.

 

Start with the Bat Wings and go from there . If they are different then your four bars will have to be worked on. The spring moves so easily because it is not in the correct cross member it should be at & degs. or a wedge put between the x member and the spring. You should have the clamps on all your springs. It's a safety thing. Yes put it together while hanging then adjust the four bars accordingly. 7 dig. caster, toe in 1/8 ", make sure the axle is square to the rear. " KISS " That is what I tell myself all the time. Jim T.

 

ALWAYS check EVERYTHING.

 

Photo # 22 of his collection shows the problem.
His 4 bars are not all the same length [that is total length from eye to eye]

 

He's right. Is there a reason the thread lengths are so different?

 

Well...I hung the spring and axle and squared it with the rear axle and installed the 4 bars as is...in a relaxed state...
The actual bars ARE the same length...

 

I want to tell you all that I am taking all of this in and learning however I have been sick since Tuesday this week and have not actually worked on the car...
My wife is also sick and we had to cancel a vacation where we rented a log cabin in the mountains (no refund) in North Georgia...
I totally appreciate all of your help and suggestions and hope to be applying this knowledge next week...

 

Still some confusion here, well in my mind at least! Are you talking about just the bars (without the adjusters installed) are the same length or the installed lengths (with the adjusters, as they are pictured) are all the same?

As it stands there is, the assorted 'after' pics, at least three different amounts of adjuster thread showing which seems curious unless the bare bars are different lengths, which itself seems very odd.

Chris

 

Thank you....please see post 42 and 44...

 

"The four bars only prevent the axle from moving front or back. The spring and perches hold the weight."
I understand that but I am afraid the axle would want to "slip out from under" the car...

"When you lowered the car the longer bars pushed the axle forward and put the spring in a bind because the adjustable perch bolts were tight."....I tried lowering it with them loose and it did not make any difference...

"Trying to correct the caster with the 4 bars and non adjustable perches will put the front end in a bind and prematurely wear the bushings."
That is why I went with the adjustable perches...

"If it make you nervous to put all the weight on the ground without the bars, go ahead and block the frame when the suspension is close full weight."
That is what I now intend to do...the car is on the lift so I won't need to block it...just set it down at the correct ht while actually being suspended...

Thanx!

 

To clear up any confusion...
The bars are all identical length without the adjusters attached...
The adjustable ends were not previously on the car...they do add some length so 3/4" was cut off of each bar to compensate...
They were added because the front end always had spacers on the rear passenger side where they mount to the frame and it seemed off center...
I figured if the angles are off they would help prevent bind...

 

This tiny little tid bit and nuggets of info should have been in your first post don't you think?
That leads to further investigation

 

Please refer to post #21. Pete Eastwood was with P&J before the 4 bar hit the market.
JUST THE MAIN LEAF for initial setup.

 

With the new bars all the same length, albeit all trimmed 3/4", can you explain how / why the pics provided show differing amounts of thread showing, which to my mind is saying they're not equal length as installed, which is what really matters and appears to be at least part of the problem. Beyond that they might still be excessively long, but we won't go there yet!!

Chris

 

see post 42....
"I hung the spring and axle and squared it with the rear axle and installed the 4 bars as is...in a relaxed state...
The actual bars ARE the same length..."

 

Front spring movemint/flex when loaded, is were all things must be in line,when it hits a bump it moves,but only about 3in. on a fairly big bump= this is the space that alinemint counts in. At full hang no load,it dose not matter much what moves out of alinemint a little,yet it is a good pointer to a prob of bind. This is ture for most t-buckets an very lite rods. [=] 4 BAR keeps caster as it swings.vs bone gets less caster as it swings down,but caster is only adjusted when loaded on level ground. Both types make front axle when in full hang,move axles back an out of line with frame spring mount. That is why all setting are done full loaded.

For transvirs front an back springs; Not all frames are sq. or flat with there mount points,so for SQ the axles cross [X] size is needed to be same as well as [ ] WB size. Balance can be checked by jacking up fully loaded{with driver or same Wt. in seat} car dead center of rearend with a < facing up on jack head pad so rear has pivit point,tell wheels are off ground. If one wheel is much higher off ground then other= car is out of balance. Adjust springs to fix/and keep frame level side to side when doing so. Could be rear or front spring/if frame an rear axle jacked up are level with each other=its the front spring that needs adjustmint. Wedage canbe used or other,like moving leafs end to end etc.

 

Bolt to bolt maybe is Easy way to understand it?

You can't assemble parts at full droop so they fit up easily and expect them to be in the right places at ride height under weight.

I know it's a pain in the ass, but so is this. Go back and read pete's post and do it that way. There is no easier way, unless you have a spare main leaf.

 

You keep writing this exact same thing which doesn't clearly answer the question being asked. Is the length of each bar the same as assembled ie. when you measure from the mounting holes on each bar as they are on the car presently do you get the same measurement? Saying they ARE the same length doesn't delineate between the physical bars being the same length or the assembled unit with ends adjusted as shown in the pictures being the same length which are two vastly different things.
You may be missing his point. If the original end were not adjustable and they were the same length and it worked fine but you have now reassembled the front end with adjustable ends and you have them adjusted to different lengths you have clearly changed the set up.

 

adjust the bar length with suspension at typical ride height.
the axle will move back from it's static location as it travels up and down.

the forward and back movement is an effect of the design, it's simple geometry.

 

After reading through all the different interpretations here. It sounds like the OP has the wheelbase set too long "at ride height" causing the crossleaf to lean back at the top.
He set the wheelbase with the spring in place and the 4 bars hanging down diagonally [they will arc forward when the suspension is loaded causing the spring issue described]

A simple fix would be to undo the 4 bars at the frame so the twisting of the spring is not in the equation, then slowly lower the frame with a trolley jack until the spring and axle line up.[you need to allow for caster] then adjust the 4 bars to re-install

The better [safer] method is to remove the spring completely and set the wheelbase and caster while the car is at ride height on stands then re-install the spring

 

Can somebody local go help this guy?

SPark

 

Why's that? The guys trying to help out from far and wide not good enough?

These 'whodunnit' type guessing games are kinda fun but often frustrating and sometimes annoying.

Pretty clear that the bars are too long and the installed lengths are not remotely equal. For some odd reason things have been referenced to the rear axle which is probably at full droop as the owner has a handy lift, but at full droop everything is out because of the arcs of the components, and what's to say the axle is square to anything.

Kerrynz has articulated an easy fix which will hopefully be followed and move this thing forward. It first needs to be installed ballpark correct, and then the strings and angle finders can come out to play.

Night shift signing out for now.

Chris

 

[QUOTE="A simple fix would be to undo the 4 bars at the frame so the twisting of the spring is not in the equation, then slowly lower the frame with a trolley jack until the spring and axle line up.[you need to allow for caster] then adjust the 4 bars to re-install
The better [safer] method is to remove the spring completely and set the wheelbase and caster while the car is at ride height on stands then re-install the spring[/QUOTE]

This is exactly what I intend on doing...
I am going to try it with the spring in first and if that fails for some reason I will remove the spring and go that route...
I will take pix and report my progress and/or results...
I still don't feel too well so I do not know if it will be today or even this weekend...

I want to thank all of you for your help even tho there were a few different ideas here the general consensus seems to be the same...
I messed up by not setting it up under load...