To the guys running 4 links in the back of their 49-54 chevys?!?!

How in the fudge are u guys running triangulated 4 link in the back of these cars?!? We have trie every which way to make this work but for proper triangulated link geometry it is physically impossible unless u put them way up high in the back seat? When i lay the car out now the rear end shifts forward about a inch that was with setting it up for ride height at 5 inches?!?! I guess im gonna have to run a parallel 4 link with a track bar since i value the back seat just curious how everyones makin theirs work?

 

Heavily modified back seat, or no back seat.

 

see thats the issue for the upper bars to be where they need to be to be within the correct geometry they would sit taller then the back seat? is everyone just ignoring that and making the best of it? I havent really seen any setups of people running the link a diffrent way. My frame is also sectioned and its setup to run a 28.5" tire is that maybe the issue im having?

 

You appear to be dead-on with the setup. I make mini-tunnels over the upper arms. The rear seat is going to need substantial mods anyway. The tunnel is going to cut it about in half.

I am assuming you cut the "dip" off the bottom of the frame, so you can lay rocker. That means that the engine and transmission are going to need to go up, making the whole tunnel firewall to bulkhead, just that much taller, since the stock k-member was under the frame. By the time you are done with the rear seat mods, you might have two bucket seats. That will be the case with a parallel 4-link, too.

 

Truck arm style. I just did an install in a '54 using Jimenez Bros. kit slightly modified.

 

With his sectioned frame, those would be through the floor.

And that kit is not the truck-arm style, GM or NASCAR. It is just a 2-link. Truck arms are made from two c-channels, back-to-back, and are engineered to twist during normal operation. Your links are tubing, and will not appreciably flex. Similar mounting profile, totally different operational principal. The articulation that does not come from the swing of the arm, comes solely from bushing deflection.

 

Well i would think if its right on that the rear end wouldnt pull forward a inch but with the upper bars as low as they are it has no option but to pull forward and with that it of course also rolls the rear end down which is why the pinion angle is fucked up. We are anticipating cutting the seats regardless cuz its keeping both factory seats since we z`d the front frame 1.5" as well since the cars getting such a large "tire" and we are making our own floor pan but the link just cant be right there and after searching is seems a bunch of guys must have the same issue looking at the bag alignment or they all welded theyr brackets in fucked up lol. Im guessing everyone must be ignoring the fact, its the only thing i see possible.

 

Now that I have stared at the picture a little longer, do you have the longer links on the top?

 

If you want the pinion angle to remain the same throughout the full suspension cycle, all of the joints on the axle need to be on the same plane, and all of the joints on the frame need to be on the same plane, too.


When viewed from the side, they would appear to have the same length. When viewed from above, the uppers are much longer.

The upper and lower bars need to be parallel, when viewed from the side. However far apart they are, height wise, at the axle, they must also be so, at the frame.

 

Take a peek at how Mat did his rear. Without reading through his entire thread, or asking him (it's 5:30 in the morning), I'm just guessing that he will have plenty of backseat room. He's not running as tall of a tire as you, but it's something to think about.

 

the correct way is that the lowers should be a little bit longer then the uppers and the pitch of the uppers should be greater then what u have at the rear end so the spacing should be larger at the front of the link then the rear according to all great suspension gurus. I belive there should be a 2" diffrence in the length of the bars if i remember correctly. I guess its one of those depending on who u ask deals but from the guy here at the local shop that builds all the magazine feature cars and trucks the lower bar at ride height should be level with the ground and the uppers elevated at the front of the link. I see what ur saying though wish i had a concret answer here... but after redoing the upper mount over and over again i just dont think its gonna pan out

 

damn thats nice... anymore info on the thread or the car that i could snoop around on?

 

Sorry, I should have posted the link to his thread, there's some pretty amazing fab work on the entire car

http://www.jalopyjournal.com/forum/showthread.php?t=601913

 

Thanx that dudes kickin the shit out if me gotta step it up some lol

 

Anyone else got some info?

 

Unless you maintain parallesim, your pinion angle is going to change substantially during suspension cycling. Not making this up. I've got 25+ years in suspension. Some pinion angle change is workable, but an excess is not.

Having the upper bars run uphill toward the front of the car puts the instant-center behind the rear axle. If you are building for pinion angle, they must be parallel, and equal in lateral run, infinite instant-center. If you are building for performance traction, the instant center needs to be ahead of the axle. Not saying what you have won't work, but what you have been told is far from ideal.

Contact ElPolacko here on the board. He is one of the finest suspension engineers that this community, and this country has to offer.

 

That right there is excellent advice.

 

I'm running a Gambino 4-link in my 54 Buick. I was having clearance issues too. Then I spoke with Alex and he told me to weld the upper arm brackets to the front of the rearend instead of on top. This gained some clearance and worked for me...

 

Thanx guys ill see what i can come up with i think the 4 link ideas gonna get tossed and were gonna go a different route. The wheels just set the rear end to high to make it work correctly

 

My 54 has been on hold for a bit, but I got my 4 link from Alex as well. He did a few build threads that show the mounts if you do a user search for Gambino_Kustoms.

Or Check out Ian's sweet 51 Chevy build- he has a back seat in his(custom though). For Ian his username is IanBerky.

 

Different car but I solved this problem by bending the top bars so that they dip under the seat.
The shortest and strogest connection between two points may be a straight line but if you build strong enough uppers they can run straight back and then kick up- the geometry is the same as if they ran straight uphill to the rear but they stay below the floor pan this way.

http://www.jalopyjournal.com/forum/showthread.php?t=546306&page=2

 

I had to built up a gusseted riser for the top links to keep things parallel using the standard triangulated four link. I never installed the rear seat before I sold the car but it looked like it was not going to be comfortable for anyone sitting in the back I will tell you that.

If memory serves correct the riser and pivot point was a couple inches away from the top of the seat line.

 

here is a picture I took of Gambino's last weekend. notice how the upper bars are placed lower on the rearend









Here is a picture off a Morrison chassis

 

found a picture from last yrs GG show where Gambino had a chassis and body with the 4 link installed. this one looks to have the upper bar sit alittle higher than how he is building them today.

 

No problems with the Gambino 4-link in my old '51. I put the bars on top of the axle housing and they still didn't interfere....it was the tunnel that required modifying the seat frame. This could be because my car was a coupe....I think Chevy put the seat further back in the sedan. Even so, I've seen it done on those models too.

 

None of u guys have the issue of the rear end getting pulled off center during suspension cycle?

 

I used GM A body links and axle on mine

http://www.jalopyjournal.com/forum/showthread.php?t=573790

 

Not enough to notice on mine

 

Thanx guys i guess im gonns try switching my upper bar mounts to the front of the axle since that wpuld give methe 4 inches the bars wpuld have to go up in the front

 

gimpyshotrods, I realize that this is a very old post but I don't see many that are recent. Anyway, I am curious of your thoughts regarding Murray Kustom Rods 3-link system? Seems less intrusive than a 4-link, and probably better geometry than the 2-links.

1039867401 by NDWEEDS posted Apr 11, 2022 at 9:09 PM