Triagulated 4 link set up

Hello....
I am working on my 32 truck that I am taking over from my dad. He was installing a universal triangulated 4 link set up with coil overs. The question I have is the instructions came with dimensions on how far from the center line of the axle to the upper and lower link mounts on the rear end. If I use these dimensions the lower links don't run parallel to the frame rails. On ever set up I have been able to look at the lower links run parallel to the frame rails. In order to run the links parallel I need to move them a couple inches more then the directions. Am I ok to do this? My thinking is that the kit is for a universal set up so I gotta think I can deviate a bit as needed?

Bottom bars need to be parallel with the ground at ride height, depending on tire size, coilover mounting point, and a number of other factors this may or may not be parallel with the frame rails. Most of the times on a Deuce frame they are very close to parallel with the frame rails.

Based on ride height and the coil overs I can get them parallel to ground I was more referring to side to side

Are you mounting them on the inside of the frame rail?

Side-to-side, the bottom bars of a triangulated 4-link should be parallel with the centerline of the car and perpendicular to the rear axle. If that doesn't happen, adjust so that it does.

Henry that is the exact 4link I have but if I go 37 apart they are close to parallel but not exact I need to figure out the dimension but I figure they would be about 39 to 40 apart

You can run a heavy line or wire down the center of the frame and locate from that. Don't worry about the Heidt measurement. Frames can be a little different. Without seeing your chassis, I can't be sure, but I would tack the frame mounts on first, then locate the rear axle brackets by measuring off the centerline.

It is the original 32 frame for the truck it has been shortened not sure how much....

I stand corrected. I pulled the bed off last night and realized that the lower bars dont run parallel to the ground. The bars are higher in the front than the back. The brackets used in the front are mounted to the underside of the frame rail nd the rear brackets are also mounted to the underside of the axle. I guess my question is do I need to raise the mounts on the axle side? Basically the mount on the axle would be more on the front than the bottom?

Thanks

How close is it are they to being level? And is that with the vehicle at normal ride height? The front being higher by say 1/2 : 3/4 of an inch is what I would believe to be within tolerance.

If you're 3" different from 1 end to the other, then I'd search for a way to lower the mounts up front and / or raise the axle mounts. fwiw/imho/point 02/etc..

I'm with what Mike said in the post above! I'd suggest getting the bars as close to parallel with the ground as possible. Might be necessary to modify the brackets to achieve this sometimes. IMO, anything more then 1/2" higher on the front of the bar is going to create more front end lift when you stand on it---good at the dragstrip but not good on the street as it will lead to oversteer on the front end when accelerating out of a corner or curve.

Some detailed photos of what you have at present won't hurt for the guys to actually see what is happening or not. As you have removed the bed that shouldn't be to difficult to get photos looking straight down on the rear end and lying on the floor taking a photo or two of the vehicle at ride height.

I may be wrong but I believe the OP is saying that he can get the lower bars parallel to the ground but is trying to get them square/inline with the length of the frame. Moving them to get them parallel should not hurt but maybe the OP should call Heidts to confirm.


I had a setup on my Cobra replica that had the lower trailing arms at an angle toward the tires at the rear end and the uppers were at an angle toward the pumpkin at the rear end.

The bottom bars do run parallel with the frame, the top bars run at an angle. Same setup, except built in round tubing instead of stamped steel, that the factories have ran for many years on coil spring rear end cars.

I would say the lower bars are about 1" to 1.5" higher in the front. I am out of town for the weekend picking up the welding machines I will post some pictures on Sunday when I get home... Thanks for the help

unless it is strictly for drag racing , some angle on the lowers is an improvement----look under a Mustang up to 2004-----------

Attachment 58233Attachment 58234Attachment 58235

Photos attached the front of the link is about 2 3/4" higher than the back of the link I think I am going to raise the rear by make new holes in the lower bracket???

If it were mine, I'd leave it alone until I could put a few hundred pounds over the rear axle to represent the bed. This'll give you a better idea of what it looks like at normal ride height.

The thing in those pics that jumped out at me was the pinion angle looks terrible! I would try to get it closer before doing the final welding. Then you can use the threaded sections to fine tune it.

Hard to tell from the pics, but Mike is right in commenting on the pinion angle. Should be a whole lot more down! I don't like that much up angle on the lower bars, if you have room to lower the bottom of the coilovers that would help a bit, but a shorter coilover or a taller upper mount (if body room allows it) would certainly help!

What if you made a new front lower trailing arm bracket that put the front mounting point inside the frame rail instead of under it. A well made bracket using 1/4" plate with gussets or boxed in should work just fine. You could then maybe move the rear trailing arm bracket out a bit more to line everything up.

Your set up isn't at ride height so none of these comments are relative-----you need to make up a pair of tubes the length the shock will be at ride height and work with that----------- and generally those kits are set up to be put on the axle housing with the rear face of the shock mount at the same angle as the face of the housing where the punkin bolts in---------

As for the angle with the frame----put the mounts at a width as wide as you can with the inward leaning of the coilover at a reasonable angle and still as wide as you can---the angle with the frame of the lower link doesn't mean much as long as its reasonable with regards to triangulation of the axle tube and the upper link----

What does concern me from your pics is the upper cross bar for the coil over mounting---it carries the total REAR weight of the vehicle and looks like the twist it will get from the load plus the bending from the weight might cause a failure-------

I Hear you on the pinion angle I know that its way off. I figured once i get the links correct I will get the pinion angle fixed. If I mount the front of the links to the inside of the frame the bars will be at even more of an angle. I think raising the rear of the bars higher into the bracket by punching a new hole in the bracket will get them within about an inch of being parallel to the ground. I added marked up the photo below with two white dots the represent the "new holes" so I can raise the lower bars?????
Attachment 58236

You do not want to re-locate the rear or set the pinion angle until you are at ride height like Jerry said. What I meant by moving the front location is only to make the lower bars parallel to the length of the frame. Not to change the height of the front bar.

You have the tires on it. So now put the bed on it and set the ride height (or put the same weight on the frame that the bed weighs). I have always had my trailing arms set at a bit of a down angle because the rear of the vehicle will squat on accerlation. Personal prefferance.

I agree with Jerry on the rear shock crossmember. IMO, that square tube isn't nearly strong enough. One solution is a heavy-wall tube with some bushings welded through.

Attachment 58237

Jack

Excellent photo showing nice (and desired) wide as possible mounting of coil overs, which also since they are close to the wheel, makes the spring rate applyed more in line with actual rate of spring-

Also, that system of arms on the rear end has virtually zero binding, compared to varying percentages for the triangulated 4 bars systems-------------

And to go a little bit further----------this rear suspension system is not one designed for the ultimate forward traction biting race set up--its for simplicity and a nice ride that can be achieved from proper choice of shock valving and spring rates on coil overs which is easy to fab and mount and makes the ride much more pleasant so the vehicles get used as compared to some cobbled up junk yard rear end assys-------------

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Originally Posted by Henry Rifle

I agree with Jerry on the rear shock crossmember. IMO, that square tube isn't nearly strong enough. One solution is a heavy-wall tube with some bushings welded through.

Attachment 58237

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Jack I thought the same thinking I am going to replace the shock mount with a 2"x2" 1/8 wall box tubing nice catch..... thanks for the picture.