[az67goat]

LEGTO,
I would recommend that you do not heat the right spring to lower that side. I also would not cut that spring. If you cut the coil you will change the spring rate. I would recomend spacing under the left spring until level. How far off are you now?

[LEGTO]

AZ67GOAT,
Since my last post I have checked the left front suspension and noticed that the problem seems to be in that area. The lower a arm on the left is different then the right. Will be taking the car to frame shop to check for a straight frame first.
With the car sitting level on the ground and putting a floor jack under the left front shock/spring mount and jacking up about 1 1/4" the rear end levels out and the front frame horns are level. Makes me think the problem is in the left front suspension area.
Thanks for the help.

[78 GHOST]

Ah, my personal favorite Pontiac problem.

I went through this song and dance with 3 different shops on 4 different occasions.

Eventually, one of the shops made a stop-gap correction by heating and bending the front anti-sway bar to establish the necessary preload to "trim" the car properly.

I wasn't really crazy about this idea, but was frustrated to the point of doing anything productive. The only problem is that when driving in this condition, I feel as if the front suspension reacts in an uneven fashion to uniform inputs. In short, a bump at highway speeds reacts to a slight amount of rocking from side to side.. unexpected to say the least.

I also had a shop pull the crossmember back into shape. According to my frame guy, crossmember spread is VERY common. If you have a LOT of shims, you might need to have a good shop pull the crossmember back into shape.

I carefully measured the body to frame and found the LH side (low) side was actually slightly higher than the RH side. Completely opposite to what I would have expected.

Since the frame off, the frame has been closely inspected by a reputable frame shop and given a clean bill of health.

At this point, I'm going to install a completely new front and rear suspension, being mindful of potential binding issues during installation. However, if things are still crooked after completion, I will happily add a spacer inside one of the spring pockets to trim the car.

After seeing exactly how flimsy the frame is with nothing attached, I have a new appreciation for the function of the frame. Essentially, it provides an accurate location for the suspension components and body. The location of individual components can, and will change over time and exposure to fatigue cycles (bumps.)

While I'm going to have to make some more measurements to check this idea, here is one thought:

98% of the time, these cars were/are driven with only 1 person (driver) in the car. It's possible that having an uneven load in the car causes uneven suspension loading when the vehicle is subjected to an impact (normal road irregularities.)

This uneven loading could be expressed in the following example comparing LH and RH front loads in an arbitrary form referencing a scale from 0-100 with 100 being the maximum force of a given impact.

LH- 100 RH- 80

Over time, the cumulative effect of this biased loading would/could result in a upward deformation of the upper spring pocket. While the potential deformation of the fixed portions of the chassis may be at other areas in addition to the spring pocket, I feel the basic concept is likely.

Couple my experience with the fact that every other "crooked" musclecar I've seen sits LH side low, and you might have a place to look.

The only way I can imagine to measure this is to extend a datum from the main frame rails under the body, forward enough to reference the spring pockets. Next measure from the datum up to the LH and RH pockets for comparison.

Only after correcting any "Frame Spread", could you then pull down the offending spring pocket, effectively raising that side.

[78 GHOST]

..Or you could just put a 1/2" spacer under the LH front spring and call it good.

[73LeMans]

I like the spacer idea.....

[retrojoe]

Well, I finally finished putting my front end back together after a major rebuild, and as you guessed it, it is leaning towards the driver side!

[73LeMans]

I just put Airlift airbags in place. Got max pressure in drivers side, and min in pasenger...no good...still not straight. Better, but not straight.

I believe the actual issue to be the spring mount itself. I think under years of stress, its fatigued to the point where its creeping closer to the top of the trunk floor up there...at least I see some stress cracks in mine.

[Junkyard Dog]

Is EVERYBODY's Pontiac A-Body like this? If not, what is the difference? It can only be two or three things.

[Junkyard Dog]

And is it a wear issue? Somebody posted a picture of a 65 with the same problem, brand new!

[YVEYANT]

Check the tire pressure before you get into the major components

[DOC]

1/2way and trips4me, How does adding convertible springs raise a car? You would think the convertible is lighter w/ a lower rated spring. I was planning on using a set of coupe springs on a convertible to try and raise the rear about 2 " from it's present sag. This post has me wondering....

Thanks

[78 GHOST]

Convertibles are heavier as a rule. There is extra structure added to replace the rigidity lost with whacking the top off.

[slowgto]

I evened my '69 GTO out! I was high on the passenger front and low on the driver's rear.

The main problem was that the top of the coil was not around the lip that places it, but on top of it. There are two pieces of the guide lip up there, one taller one on the inside, and the shorter one on the outside. As I reinstalled the spring several times, I noticed it was difficult to get it to stay around the shorter, outside lip. It kept resting on top of the lip. This jacked my pass. front up an inch and pushed the opposite rear spring down 2", giving me the "sag" discussed here.

I imagine many people see their spring go on the taller, inside lip, and assume the outside lip will line up as the A-arm is raised and the spring compressed. Don't fall for it!

This is extremely difficult to see and I don't think it can be seen with the coil compressed in the car. I saw mine with the spring partially installed, when the top two coils were not compressed, and I had my eyes between the pivot bolts.

I urge you guys to pull that high side front spring out and carefully install it, while confirming that it wraps around that lower, outside, lip.

My car had the sag when I bought it, then still had it after a completely new suspension. I thought the car was bent. I didn't cry, but..you know. But I kept after it, and now the car is level, front and back. Keep after it! Hope this helps.

Also, you can eliminate the rear as the sag problem by jacking up the front and placing jackstands on the frame, in front of wheels, taking the front coils out of the equation. (But you have to have the front jacked perfectly level). If the back is then level, you know its the front spring pushing that back one down.

[Junkyard Dog]

I'll try jacking the front up for diagnostic purposes as you have described, but it seems if this was everybody's problem it would be equally likely to occur on either side. As it happens, the complaints are almost entirely of sagging on the driver's side rear.

[DIYGuy]

Originally Posted by 78 GHOST

Couple my experience with the fact that every other "crooked" musclecar I've seen sits LH side low, and you might have a place to look.

My '70 Le Mans convertible sits RH (passenger side) low in the rear, about 1.5"... sigh.

[Brett_ty]

I have a 67 GTO, Got it home and noticed that it sits about 1 1/2 inch low in the Left rear and higher in the Right front. I initially thought, like everyone else here that it has to be the coils. However, I went a step further and replaced the 10 Bolt rear, with a Currie 12 Bolt, Hotchkiss rear control arms, braces, sway bar, new coil over shocks, and new coils....as you would have guessed it the sag is still there. So I placed a 1/4 in steel plate spacer under the right coil, and some coil spacers (which drives me nuts to have in there) to spread the coils out and give some lift to the right rear. So know, instead of 1 1/2 inch sag...its only a 1/2 inch sag.
At this point I am guessing that it has more to do with the front end than with the rear.
Solutions to this that I have read off this post are:
1) Air bags
2) Spacers/bushings under L/rear coil
3) and one person had success with re-locating the spring in the r/front corner.

Any other fixes/findings?

[RANDY P]

I'm glad I found this place, it's great - been a lurker here for 2 or so years. Ran across this thread - I have this issue.

I have a 70 LeMans sport I'm in the middle of finishing - started life as a 350 2BBL, now sporting a .030 455, Hyd. Ultradyne Cam, Dougs Headers, 2,000 RPM stall and a bulit TH350.

Still has 8.2" lame open rearend with 200 MPH (2 something) gears.

Anyhow, has anyone come up with a decent solution to the dreaded lean? Mine leans hard to the left. The car has had the entire front end rebuilt - the PO did it and used Moog factory springs - Car sat with a huge LH lean, about 1.5" difference, and RR permanently looked like it was lifted by a floor jack. Not attractive.

Figured it was just some problem with spring indexing, and I was going to lower the car on suspension techniques springs - so I drove it like that for awhile.

Dropped the new springs in last weekend and lo and behold, it still sags, to the point where it looks like the RR of the car is still so high it isn't even affected by the lowering springs - looks the same as when I started.

I managed to minimize it by trying to reset the front a arms -loosen, jounce the car, pull the LF (lowest point of vehicle) up with a jack, had passenger in passenger seat and then retorqued all bolts. - That gave me about 1/2" improvement in both LF and RR heights.

I then reindexed the RR of the car, spinning the spring 1/4 turn at a time, bounce the car, until I saw something - and from what I can tell it gave me another 1/4" or so lowering on that corner.

Still not quite right - so I did this -

the kicker - I went ahead and simply reinstalled a MOOG spring in the left rear to bring that end up since that was also noticably lower than the RH side.

Now down to 3 lowered springs, and a stock spring in the drivers side rear.

On flat ground, it's pretty damn close now - considering where I started it's a significant improvement. I figure when the springs actually settle in (there's less than 40 miles on everything as it sits) it should be basically spot - on. Another weird thing is that the car had less understeer - more turn-in after I was done - I could feel the difference in steering response.

It seems like a cheap hack to mix the springs, and truth be told the factory springs have less turns per coil and it's a thinner wire so it's rebound rates are in fact different, but considering these cars weren't made straight to begin with and it's primarily drag race use it's not going to matter - corner to corner weight distribution isn't so much of an issue when you're going in a straight line.

I'll post some pics after the suspension settles in, hopefully it works.

Here's a crappy phone pic from this morning..

[78 GHOST]

Ahh, a classic from the archives..

Glad to hear it! Yeah, I know mixing things is not the ideal fix, but what the heck.

Since I've put mine back on the road, I haven't really checked yet. At a glance, it seems pretty level.

I've assembled my car from a complete state of disassembly with an eye toward controlling those mechanical factors which are manageable. Despite precision in the assembly, it's still possible to have cosmetic imperfections which defy mechanical solutions. In separating the two categories, it's crucial to remove any false frames of reference which lead us in the wrong direction.

One thing to mention is the rear bumper. I think the funky mounting PMD did with the rear bumper influences the appearance of the car from the rear.

Most A-bodies have their rear bumper mounted so the forward edge of each side is slightly lower than the rear.. almost like it's tilting down in the front. As the top of the bumper is curved, tilting the bumper introduces an optical illusion regarding how the car sits.

This is why I try to initially ignore (just) how the car looks and use other information to verify stance, such as measuring positions on the body unlikely to change. I tend to ignore where the front fenders are and focus on the body shell. The fenders can be mounted in such a way as to be canted upward or down, making the measurement of the front wheel opening virtually useless.

*I assume all suspension components are is good shape, and tires are evenly worn.

-Perform all work on a level surface. As a level surface is hard to find, focus on eliminating any slope left to right.

-Remove all unnessary crap from your car, including the trunk.

-Focus first on ensuring the tires are the same size and inflated identically.

-Jounce the car.

-Collect baseline measurements to verify what you're seeing is really a measurable problem. I suggest measuring with a plumb bob (fasten a heavy washer to a string) and measure from the apex of each wheel opening. I also like to measure two places on the bumpers front and rear and eight places on the frame.

The wheel opening and bumper measurements are hopefully going to coincide with what your eyes are telling you.

The eight places on the frame are to establish where the chassis is sitting, regardless of what the body is doing. Start with the four corners of the frame and pick four points between the front and rear corners.. such as the area under the edge of the firewall and where the forward mount for the lower rear control arm is.

I also like to measure the thickness of the body bushings to verify the body is sitting level on the chassis.

Once you've gathered your baselines, you can move on.

-Jounce the car again.

-Remove the anti-swaybar attachments front and rear. This removes any bias your swaybars may introduce. I'd suggest visually examining the car to see if any changes happened. Next, you should check your four corner measurements on the frame and see if anything moved.

-If something moved, consider diagnosing which swaybar is the problem.

-Disconnect one end of all four shock absorbers.

-If nothing moved, take the next step and loosen all suspension bushing attachments, jounce car, and retighten fasteners.

-If you're still fighting a problem, measure the apparent length of each coil spring to determine any obvious irregularities.

-If you have a length problem, insert spacers to shore up the short spring.

I hope some of this helps.

[RANDY P]

Ghost - I'll try those next time I get her out in the driveway -

I tell ya, i'm determined to lick this problem. The alignment guy at the local Les Schwab drove away in the car and it was easily apparent it was still cocked a bit.

I'll give it about 500 miles before I try again. Next step is to redo all the bushings in the back - might as well since I need to box the lower arms anyhow and install adjustable links up top.

rjp

[gtopont]

be sure that your sping ends are faceing foward.....