1986 Carrera Targa 3.2 pulls left under accelleration

[rgmrgm]

If the circumferences of your rear tires are not equal a limited slip differential will cause noticeable pulling under acceleration.

[RSTarga]

Originally Posted by qship510

Amazing....

Doubtful that you have a corner balance issue. Extremely doubtful.

You have a rear control arm bushing issue

^^^Very wise words.
Corner balance is a fine tuning tool. Has very little to do with a torque steer problem.
Look for anything loose or worn at the rear.

[twickes]

Did you check the wheel bearings? Some of your symptoms are similar to that of a loose hub.

[ClickClickBoom]

Originally Posted by RSTarga

^^^Very wise words.
Corner balance is a fine tuning tool. Has very little to do with a torque steer problem.
Look for anything loose or worn at the rear.

Indeed,
My car was wildly out of corner balance, after the POs, kid thought he would try to lower the front for his dad. The problem only showed up at threshold braking, where one tire would lock before the other. Otherwise it handled just fine.
Something is loose.

[travels68]

Well crap - after all the corner balance nay saying I'm back to state of many likely causes again (including corner balance).

I was reading over the shop charges and they replaced the rear 'banana arm bushings' so I believe that knocks out the rear control arm busing theory assuming we are talking about the same thing here.

More info: My FRONT bearings (esp front passenger) were loose and needed adjustment. I tightened to the point the bad one no longer clicked when pushing top of tire with foot with car on ground. Both front bearings quite tight now as far as I can tell although both have a tiny amount of 12 to 6 (clock) movement when off ground with tire attached. Unfortunately this did not fix the problem.

I've swapped the front tires left to right to see if the problem reverses but can't imagine I'd be so lucky - I will test drive this afternoon.

How about the rear sway bar drop links/bushings? Front control arm bushings? Both have NOT been replaced.

Rear bearings seem OK as no rocking wheel play when off ground.

Here's the possible list now:

Corner balance
Sway bar drop links?
Rear tire/wheel diameter difference - limited slip diff

I'm going to check that at-home alignment link as well... thanks all. Keep the suggestions flowing.

-Kale

[qship510]

The fact that they called them "banana arm bushings" makes me supicious. There are inner and outer bushings, yes? Did they do them all? Did they tighten everything to spec with the suspension loaded?

If you have a GoPro film each rear wheel while driving and watch the lateral movement; that will show you which side to inspect further

[travels68]

Yea.. I thought the 'banana arm bushing' term was a bit strange. And they didn't specify which ones.

I'm going to get under the car and take a close look back there to see what looks new and what is old. I like the go-pro idea - never thought of it... and I own one!

Anyhow, should I also take a torque wrench to the rear suspension components and make sure everything is tightened to spec?

Here's the new list (as I haven't had a change to troubleshoot since last week..and left some things off):

Rear suspension bushings, old, or loose components
Front control arm bushings (I haven't replaced them - everything else in front is new)
Improper sway bar loading - sway bar preload?
Rear tire diameter issue / LSD

... and dare I suggest

Corner Balance

Thanks all.

-Kale

[gtc]

Hey, it's just as incorrect as calling them control arms.

Originally Posted by qship510

The fact that they called them "banana arm bushings" makes me supicious. There are inner and outer bushings, yes? Did they do them all? Did they tighten everything to spec with the suspension loaded?

If you have a GoPro film each rear wheel while driving and watch the lateral movement; that will show you which side to inspect further