Rear end housing not level

[wvspeedfreak]

I have a 1980 Buick Regal I bought as a rolling chassis and have been working on it as I get time.It is tubbed with a ladder bar/coilover rear suspension.
The problem I have is the rear end housing is not level left to right as viewed from the rear.The passenger side is 1 1/4" higher than the drivers side.This is the housing itself.If you jack the car up under the center of the housing the passenger side rear tire comes off the ground way ahead of the drivers side.
I have been trying to figure this out and with all the heims/rod ends adjusted evenly,the only way I can get it level (or nuetral) is by placing the front of the passenger side ladder bar in the bottom hole and the drivers side in the center hoe (there are 3 holes total on each side).
Any help figuring this out will be greatly appreciated.I am assuming something must be bent or twisted but I am not sure what.
Thanks in advance.

[HPDRIFTER]

There are smarter guys than me on here (dang near everyone), but do you think that the previous owner may have had the chassis
pre-loaded to straighten out under acceleration loads? Ask him, if youcan. Maybe he can/will help you figure it out. Good luck.

[slightly tweeked]

There are smarter guys than me on here (dang near everyone), but do you think that the previous owner may have had the chassis
pre-loaded to straighten out under acceleration loads? Ask him, if youcan. Maybe he can/will help you figure it out. Good luck.

That is probably what your problem is,the suspension is pre loaded.Leave it alone till you run the car.

[chpcamaro]

try this get a angle finder and put it on the rear of the axle brackets and make sure you don't have a rotated axle tube. are the axle tubes welded to the center section.
if it was for preload it would be a adjustment in the hiems or if it had double adjustable ladder bars i can't see why anyone would weld the bars in with preload built into form the start? preload is just for adjustment if for some reason you need it.you need to check it before you run the car last thing you want is to get hurt or total a car to find out if it there for a reason . i hope this helps if you need more help let me know
rob

[wvspeedfreak]

Thanks for the replies.I am just trying to get everything in a neutral starting point.I have never had a ladder bar/coilver car so I am learning as I go.
Also the right rear shock spring had been threaded up a good bit tighter than the left.I believe someone had done this to try and mask the problem with housing sitting crooked.
The axle tubes are welded but I will check with an angle finder to be sure one isn't twisted.

Edit: Just to make sure.....wouldn't the housing sit the other way if it was pre loaded?The way it is now it would have alot of weight off the left front.Once again,I am new at this so please correct me if I am wrong.

[Dave Morgan]

WV,
First-off, I congradulate you for even looking at the housing. Most of the time, they are neglected.
Which differential do you have? 10-bolt, 12-bolt, Dana 60, Ford 8.8 or Ford nine-inch?
You'll have to remove the housing from the car to properly inspect it and I suspect chpcamaro is correct that you have a housing tube (or both) that has rotated. Unfortunately, you also may have a huge amount of twist in the car, although that area is normally not a flex problem for your bodystyle car (your flex issues are in the firewall area.) Let's focus on the bent housing idea for now...
All drag racing differential housings want to toe-in, which is why we place a truss at the rear of the Ford nine-inch and it's why some racers install diff covers that have ears on them so a brace can span from the cover to each housing end.
Occasionally, they will flex upwards so that there would be a camber change, but this is rare and normally due to simply having a junk housing (new or old).
It sounds as if you housing tubes have rotated and this is easy to check. Just place an angle finder anywere on one ladder bar bracket, then place it in the same location on the other bracket. If these two angles are not the same...BINGO.
If you have an integral differential (10-bolt, 12-bolt, Dana, 8.8) then the problem may be in the area where the housing tubes fit into the cast center section. From the factory, there are only two plug welds that secure the tubes to the center section. Just make sure there is a weld bead 360-degrees aroung the tube. There is also a chance that your housing tubes are not strong enough. Most builders use 3 1/8-inch OD tubing with a .250-inch wall thickness.
If you have a nine-inch, the problem will be harder to fix because there are internal bulkheads that need to be added to anchor the tubes to the center section. If this is the case, you'd be better off buying an aftermarket fabricated nine-inch housing. There are tons of companies that make acceptable versions of this.
I hope this helps.

[wvspeedfreak]

Thanks for the tips!It is a GM 12 bolt rear.I am going to check the things you just talked about.Hopefully I can pin point the problem.

[wvspeedfreak]

Here are some pictures so you can get a visual on what I have going on.As you can see the drivers side front is in the middle hole and the passenger side is in the bottom.In this position the housing is sitting level and I can remove and reinstall both front ladder bar bolts with no problem,there is no pressure on either side.
I put an angle finder on the rear of each ladder bar bracket on the housing and the difference between both sides is 2 degrees.

[wvspeedfreak]

As you can see in this pic the housing sits level.If I move the passenger side ladder bar up to the middle hole like the other side is I have to actually push it up with a jack then the housing sits high on that side.

[wvspeedfreak]

another pic

[wvspeedfreak]

Last one...other side

[chpcamaro]

wait is that a welded peice added to the rear of the ladder bar i see in the picture can you get us a picture of the bars mounted in the brackets at the housing please
thanks
rob

[chpcamaro]

hey dave look at this picture do you see what i see
it looks like someone extended the lower ladder bar tube to me????

ladder1.jpg (71.04 KiB) Viewed 10202 times

[chpcamaro]

also there is a few things i would feel better that you look at before you run this car.
the front ladder bar mounts if you have room to plate the front of them and install some type of gusset to keep them from being pushed forward. i hope i explained that right.
and i would like to see some close up shots of the brackets mounted to the housing
thanks
rob

[wvspeedfreak]

The part you are looking at is actually a mount for the diagonal track bar.I will get some pics posted up of the rear housing where the bars attatch.
Do you think 2 degrees difference on the rear brackets could be the problem?