1986 Regal-Unequal ride height rear suspension

[kustomkyle]

I have a 1986 Buick Regal Limited with a 307 Olds and it came from the factory with the base (non F-41) suspension. It has 14" rallyes with matching tires all the way around. When I first bought it I noticed it had some sag in the rear suspension. I also noticed that the driver's side (left) sagged a little more than the other side. At the time it had 73,000 miles. I put new Monroe (regular gas) shocks in the rear with no change. I drove it for about 2 years as is, but realizing the rear frame rails were shot, I bought a repair kit from Conrad Lozier and had a friend install new rails with new polyurethane body bushings.

While replacing the rails, I made sure everything was measured out so that the lengths were the same. We also made sure that there was an even gap between the frame and the inner wheelhouse; there is now a 5/8" gap on each side. Previously, since the old body bushings were shot and squashed, the frame almost touched the inner wheelhouse on both sides. We also replaced the two cage nut retainers and the surrounding metal on the floor behind the wheels because of some small rust holes around the openings (otherwise the floor was perfect). When everything was done, the rear of the car looked better and did not sag as much as before. However, the driver's side still sat lower.

Next, I replaced the rear springs with low mileage ones off an '84 Monte Carlo SS. I also put in new rubber insulators. This made the car look right and level front to back, at least on the passenger's side. The driver's side STILL has a slight sag though. I went ahead and measured the ride height (ground to the wheel lip) and the left is 1" lower than the right.

What exactly could the problem be? When taking out the body bushings and hardware I did not notice any "shims" that are supposedly in some cars from the factory, just the same amount of washers in the same places on each side. Again, we also made sure that there was an even gap between the body and frame. So, I am fairly certain that the problem lies in the suspension. Are springs ever "shimmed", or should they be shimmed? What else could cause such a problem? Any help would be appreciated.

 

[Phoenyx]

Try swapping the drivers and passenger spring. If the sag is reversed, then go get new springs. If the sag is still there, then something must be bent somewhere.

 

[kustomkyle]

I might try that, but the problem is that it was like that before the springs were swapped or the frame work was done, so I must assume something is bent like you said. Would you happen to know what could be bent that would cause sagging? I can't remember anything looking out of place or bent down there. Trailing arms? If anything, wouldn't just the bushings go bad in those?

 

[Blake442]

Don't forget about the front end!

Overly worn front springs, suspension bushings and/or ball joints can cause a lean like that too...

 

[Phoenyx]

Good call on the front end. How does it look from the front?

Another thought. Maybe something with the spring perches? Or if it has those rubber isolator pads, mabey one is missing, or worn?

 

[kustomkyle]

The front looks level and everything seems to be in good shape (ball joints, tie rods, etc.). Everything is original in the front though except the shocks (Monroe Sensatracs) and the centerlink. The car currently has 95,000 miles. I was thinking of redoing the front suspension but I don't have money to throw around replacing parts that are still good. Basically the car looks good front and back on the passenger side but the driver's side still looks like it has a load in the trunk or something.

As far as the back goes, I took out a rubber insulator from each side and replaced them with new ones when the springs were changed. The frame was good with no rust out where the springs go and the perches on the axle were fine too.

The only thing I can think of it being would be the springs (shouldn't be) or maybe the body mounts in front of the wheels are causing it (I haven't replaced any of those yet). I wanted to get new springs but I didn't want to go with the base replacements since they wouldn't last long, and the F-41 replacements are apparently limited production because they are hard to find and when you do find them are about twice as much as a regular pair. The S-10 springs that everyone uses didn't sound too appealing since they are supposed to drop the car a little bit and are way too stiff for me. I didn't anticipate the low mileage higher rate springs to be problematic.

Does anyone know if certain cars were like this from the factory?

 

[Phoenyx]

I never thought of the body mounts. Just measure the distance between the body and frame at all ur mount points.

And about the springs. I have read a few stories about people buying new springs. And they were bad right out of the box. I still say you try swapping your springs (not swap sets, swap them left to right) and see how the car sits. And then go from there.

 

[foxtrot]

Unfortunately I don’t have an answer for you but both of my Regals(1986 && 1987 ) are like this and I couldn’t figure it out. I should also mention that they have been like this for as long as I can remember (about 15 years).

 

[shotgun]

Measure your car at all four fender arches to the ground on a level surface.

Also measure the frame to ground from the #2 and #4 bushing.

Compare and go from there.

 

[Blake442]

For what it's worth, the Monte SS I pulled those springs out of sat perfectly level in our shop...

I was under the impression earlier that you already replaced all of your body mounts, not just the rear ones.
I'd finish the job and see where you're at...