Car pulls to the left

[Rodsrsr]

My cars been pulling to the left since I've owned it. I guess I'm just used to it, and since I don't drive it too often I put up with it, but now that I've gone through pretty much every system on the entire car, its finally time to see if I can fix this once and for all. The car is a 76 coupe with a turbo 3.2 mated to a 915 gearbox. The entire suspension has been gone through and upgraded. Turbo tie rods, new struts, 23mm hollow bars with a 22mm through the body sway bar. all other components like bushings, ect have been replaced. Nothing in the front appears to be bent or have sustained any type of significant impact. The rear has 28 mm hollow bars, (indexed correctly at least from a visual height standpoint) factory rear sway bar, rebel racing coil overs (150 lb helpers) with gusseted shock towers. Bananas looked good when removed for new bushings, but strictly a visual inspection. The car has been aligned and I remember the tech saying that he couldn't get the left rear into spec. I don't remember specifically what was off, but being that he couldn't adjust it to spec he believed that something had to be bent to cause this. I guess this is the first place to start but where? I don't see any evidence of anything bent and short of the bananas, everything else has already been replaced. It takes very little effort to keep it straight, but if you completely let go of the wheel you'll be in the left lane. Never been corner balanced also if that helps and the tires seem to show normal wear patterns. Looking to the forum brain trust for assistance.

[Rodsrsr]

Please excuse my dog photo-bombing the pic btw.

[Tom '74 911]

If the alignment tech mentioned that one of the corners couldn't be set to spec. - there's a big clue to start with. Trailing arms CAN/DO get bent.

Also - get it corner balanced. This is especially important if you've messed with the ride heights & suspension in general (which is sounds like you have).

[Rodsrsr]

Thanks for the response. This was my next question. Is there a way to check a trailing arm? I've had them both out to replace the bushings and they looked fine, but maybe the eye cant discern a slight bend which might cause a problem?

[scary driving]

First off... If it is misaligned, it will yaw (pull to the side). Now, you mentioned the suspension has been gone through. Does that include trailing arm bushings and spring plate bushings? It's pretty hard to bring it to spec if those are not ok. Also, when your tech said it couldn't be brought to spec, did he mean toe? Camber? How did he measure? I'm going to go out on a limb and guess it wasn't a tech with porsche experience, otherwise, he would have given you a diagnosis on bad bushings or bent trailing arm. Couldn't be brought to spec sounds like "I have no clue what to do or what is going on..." Before you get sticker shock from the price of a trailing arm, take it to a porsche specialist. If there is not one in your area, you will need to do it yourself and spend on a few tools, such as a makeshift alignment table (if you need help with it, I can help you keep the cost reasonable).

[Plays with cars]

You're probably looking for a deformation of only 2ish degrees if he was just out of range when doing the alignment. Probably really hard to see w/o measurement equipment. I suspect that if you could see a bend in the trailing arm, that it would be so far out that you wouldn't be driving the car.

[jason2guy]

when the rear ride height is set too low it becomes difficult to toe out the rear wheels. you dont want toe out in the rear but because its low an abundance of toe in exists so to try to get rid of that condition u need to toe out the setting.
there is a mod to the spring plate that can give u a little extra room. the lower most bolt hole gets elongated to allow the swing arm to move back a little

[Rodsrsr]

Originally Posted by scary driving

First off... If it is misaligned, it will yaw (pull to the side). Now, you mentioned the suspension has been gone through. Does that include trailing arm bushings and spring plate bushings? It's pretty hard to bring it to spec if those are not ok. Also, when your tech said it couldn't be brought to spec, did he mean toe? Camber? How did he measure? I'm going to go out on a limb and guess it wasn't a tech with porsche experience, otherwise, he would have given you a diagnosis on bad bushings or bent trailing arm. Couldn't be brought to spec sounds like "I have no clue what to do or what is going on..." Before you get sticker shock from the price of a trailing arm, take it to a porsche specialist. If there is not one in your area, you will need to do it yourself and spend on a few tools, such as a makeshift alignment table (if you need help with it, I can help you keep the cost reasonable).

Correct on the tech. It wasn't a Porsche guy, just a shop that did 4 wheel alignments, but now that I think about it, he said the toe was out by a few degrees and he wasn't able to get it into spec. (only on the left rear wheel) I know that I replaced the spring plate bushings with aftermarket versions when I changed out the bars, but not the bushings where the trailing arm mounts to the body because at the time I thought they looked really good. The car has a bit of negative camber but he got that exactly where it was supposed to be so I'm sure it was the toe.

[Rodsrsr]

Originally Posted by jason2guy

when the rear ride height is set too low it becomes difficult to toe out the rear wheels. you dont want toe out in the rear but because its low an abundance of toe in exists so to try to get rid of that condition u need to toe out the setting.
there is a mod to the spring plate that can give u a little extra room. the lower most bolt hole gets elongated to allow the swing arm to move back a little

Interesting. Well I just measured it and the right rear is just over 24 1/2" to the flare with the left slightly lower at 24 1/4". I don't know if that's low enough to cause an issue but they aren't even at any rate. I'm starting to think that new bushings, adjustable spring plates and a corner balance may be the ticket. Now I remember why I just put up with it for so long.

[Helix8]

I had a similar problem with my '84 MY pulling right though. It had been aligned twice by a tech that said he was familiar with Pcars but not a specialist - after his two goes I took the car to one of the few alignment and corner balancing specialists in my area. Car was aligned and corner balanced - the corner weights were way out - difference is night and day - the car goes straight and steering is remarkably lighter. Corner balancing fixed my issues.

[RDM]

Anything done with the brakes? A non-retracting caliper can cause this kind of trouble.

[Driven97]

Do you have a printout of that alignment sheet? Aligning the rears of a torsion bar car is a ***** show, super difficult if it's just a mom&pop shop who hasn't done one before.

I wouldn't worry about anything else until you can be sure all four wheels are pointed in the intended directions.

[Fast Freddy 944]

Nice ride! I learned that it being out of alignment can be an issue, a warped rotor makes noise and causes some dragging, worn suspension parts, tire wear, and the most scary of all, a bent frame. Good luck!

[scary driving]

So the trailing arm bushings were not replaced. I'd start there. It's 80dls for the bushings vs a few hundreds for the trailing arm, which will need the bushings anyway. Again, you are in CALIFORNIA! You have like the highest concentration of porsche techs over there. Take the car to an all porsche shop, not the dealer. I'm pretty sure that you're going to dodge the bullet with this one.

[Rodsrsr]

Thanks all for the help guys! No concerns with the brakes. I maintain them on a regular basis. New rotors and rebuilt boxster calipers all around, so their in good working order. I guess I'll have to commit a weekend to doing this. I indexed the bars myself and got them very close, (after a half dozen attempts) but I used the existing old style non adjustable spring plates. This was years ago and I didnt understand the importance of the the corner balance on these cars, so I guess its a set of bushings with adjustable spring plates, then the painful part of taking my car to a shop for a corner balance. It may be a while but I'll update this thread with the results. Thanks Pelicanites!

[r-mm]

What condition are the wheel bearings in? This is often a symptom of a bearing that is on its way out - the extreme loading from acceleration exacerbates play in the bearing and the wheel doesn't track true.

[hcoles]

a front brake piston may have rotated - I see this on my car whenever I look.

[Rodsrsr]

wheel bearings replaced along with all 4 calipers. Possible but unlikely. I did however find the specs from the alignment I had done, maybe someone can see if anything stands out.

CAMBER
front left. -1.0 front right -1.1
CASTER
front left. 4.9º front right 6.1º
Toe
front left 0.12º front right 0.16º

CAMBER
left rear -1.5º left right -1.6º
Toe
left rear -0.16º left right 0.11º

Cross camber 0.1º
Total toe -0.05º
Thrust angle -0.13º

[gper]

Have the tires been changed since you have owned the car?
If not, it could be a tire causing the drift. Swap the fronts left>right and see if the pull changes direction.

[jason2guy]

you want 1/16" toe in on each wheel in the rear or the car will be all over the place. not sure what that is in degrees but i see the specs uve posted and it looks like ud be able to get that