Technical Coil over Rear End Not Level

I am trying to adjust a coil over sprung rear end in my 31. When the car is on frame support, with the rear end hanging, the passenger side is about an inch lower than the drivers side. I have measured most every dimension I can think of and they all seem within forgivable range of where they should be. Perhaps this is a normal situation, I suspect not, Suggestions, please. The car has a ladder bar setup from Pete and Jakes and the frame seems to be straight and square.

 

Does the car sit level on the ground? If so, why worry about it?

 

What is locating the axle from side-to-side?

If it is a Panhard bar, is the lower side the one that does NOT have the end attached to the frame?

 

Yes, the panhard bar is attached on the high side and the car does not sit properly level when on the ground. Same attitude is displayed on the ground, only less difference in height.

 

I had the same problem with my just-finished '31 roadster that is for sale in the HAMB Classifieds now.



Two things to do: Check for binding in any of the components, if none change the coil-over springs side-to-side. If these two checks don't show you the problem, go back to the basics again, you've measured something wrong. Good luck!

 

Loosen the jam nuts on the Panhard bar, and shorten it.

 

Coil wire diameter and free length the same on both shocks?
It happens!

 

Is your frame twisted?

 

I've changed my Panhard length enough times to also see this effect.

 

Aldan American coilovers, rebuilt by Aldan 3 years ago. The panhard bar also determines the lateral placement of the rear end in this setup, so it can't be altered too much from where it is. I started this question as I am going through the suspension and steering setup and I put a new Borgeson steering box in and decided to address some other ongoing issues. I have been reading various threads about steering setup, alignment etc. and thought I should pay more attention to getting things set up better,
it can lead to finding some totally unknown, hidden stuff. Anyway, I am going to swap the shocks side to side to see if it makes any difference, other than that I can live with what I got. If it ain't broke yada, yada, yada.

 

Unbolt the panhard and see if the issue is still evident.

 

Move the coilovers from one side to the other and see if the problem follows.


Edit:
MissysDad1 already suggested this - my bad!

 

OK, I will get the rear end free from the panhard and try to check for any twisting in the frame as well. keep the suggestions coming, thanks.

 

It is the panhard bar setting, I unhooked it and the axle is level. I adjusted it a couple of years ago to give equal tire clearance on both sides, I never noticed the change of angle until now. I am finding that the side to side issue is more about the bodywork than any suspension problem. Regards to all, thanks again.

 

Is your panhard bar level at ride height?

 

A panhard bar should as long and as low as possible. 59-64 Chevys are a good example. I salvage them and the mounting hardware every chance I get.
A high short bar will make the car jerk from side to side over bumps. One tire hits a bump and raises and the rear end rotates about the other tire. This makes the high bar pull or push side to side.

 

See?

I do know a couple of things!

 

You need to make sure the car isn't "Wedged" [ Twist or front end not being level]

Place a piece of angle steel on a trolley jack [like an inverted "V"] and jack up the rear under the diff centre.
The car will now be supported on 3 points like a triangle [2 front wheels and diff centre]
Now measure the frame for level while the rear wheels aren't touching.

If it is not level ,check the heights at the front frame.
If the front is level but the rear isn't, the frame is twisted.
If the front isn't level and the rear isn't, the front end is causing the issue.

If the car is level [both front and rear] , then you need to repeat the same process at the other end by jacking up the front in the centre.
This will see if it is the rear that isn't level.

Sometimes a leaning front will place nore load one side at the rear [cross leaf springs can be a problem]

Next , make sure one of the ladder bars isn't preloaded

 

The last line is where I would look.

 

Ladder bar 3 link street use with out open rear , I know peps doing it for long time ,its very hard on weld ,weak frames & hiems ext .
Even harder on stif caged frame ,this is why good 3 link have safety hoops going from front around threw bolt if hiem brakes.
Its good for straight line , but on drag set up slicks side walls flex in turns witch helps .

 

adjust the coils until it sits like u want it....ur talking about 1/2 inch on each side ....don't over think it

 

I have a very similar problem with my '50. The passenger side is higher when the car is on the ground. My PHB attaches to the axle on the passenger side.

I could try swapping the springs side to side if you guys think that may be part of it.

PO had spring compressors set up as extenders on both sides to lift the rear and level. I was going to compress the high side until I decide what to do long term, but if there are other possibilities, I will explore those first.

 

Wedging anything in the coils of a spring can really mess with the spring.

It can actually damage the metal. I would not be surprised if this is the case here.

 

That is what to do. It will change with up and down movement.

 

What's the other one?

I know there's one in every crowd, today it's me!

 

I don't give away all (both) of my secrets!

 

I've had this problem several times with customer and my own chassis. For the most part I have used Aldan coil overs for most installations. In several instances I have furnished new springs which seemed to solve the problem. If I had not retired from the chassis business I would have tried to put a deal together with Ride Tech, I think they are the current leaders in coil over suspension

 

WOW ! You guys will definitely keep me busy. I am back at installing the new steering box and trying to get the alignment somewhat close to one of the multitude of choices I have read. I am amazed that I
have survived driving this beast as long as I have, seeing all the things that are fundamentally wrong with it. I am having more fun with this than I ever thought possible. Keep on keeping on. Cheers.

 

I suspect you may be right. I ordered a set of '79 El Camino springs last night. Gonna kill 2 birds with one stone.

 

Op is your set up a adjustable coil over?
I have went back & read threw ,
Have you set roaster on known level surface, then have wheel sitting race block or other , level frame out on all 4 corners, front to front then rear to rear,
Then start taking measurements from all mounting / weld in points to floor ,
Then disconnect Panbar and adjust frame to desired ride height, pan bar might need to be changed reinstalled ,
Car should be set up with total gross weight , corner heights are going to change , no matter if you set up with driver , then add passer , or no weight in either seat, that just the way it is ,
Im usually by myself so I set my car up with my body weight in the driver seat and scale the car out, when I'm not sitting in the car ,driver side is a little higher than the passenger side .
I also balance car with every part / item I install.
50/50 side to side with me in seat.