ARGH – ongoing alignment issue and steering wheel at 11 0’clock positi

[westsiderkg]

Guys –

Wondering if anyone else has had this issue.

I picked up a ’01 996tt a few months back and since then I still, after 3 attempts now, can’t find anyone in western pa who can fix the alignment.

First, for the vehicle to go straight the steering wheel needs to be held at the 11 o’clock position. If I let go of the wheel, seconds later I’m on the right shoulder of the road. If I hold the wheel at 12 o’clock, I’ll immediately drive directly into the right shoulder.

The first shop claimed they adjusted the front toe, but couldn’t loosen the rear to adjust the toe/camber since things were ceased up. The second shop also claimed they adjusted the front toe, but couldn’t adjust the rear because their machine didn’t fit?

I read a ton of posts on this already. The brakes are all in working order, new pads, and new rotors. Suspension components are also in good working order.

Anyone else go through this before and realize success in the end? I can’t imagine driving long term like this as I feel its quite dangerous to constantly be pulling to the right and steering left to go straight.

Advice appreciated!

Edited May 23, 2012 by westsiderkg

[wvicary]

The toe might be in spec but the alignment garage also needs to centre the steering wheel via the same threaded area on the rack that the toe is adjusted not removing the steering wheel and repositioning it. Any capable garage should be able to do this if nothing is worn/bent.

[Q-Ship986]

A vehicle's "drift/pull" tendancy describes how it drifts or pulls to one side of the driving lane. It is customarily tested at highway speed on a straight stretch of road in the driving lane (usually the right lane) with nominal crown. "Drift" is observed if the steering wheel is judiciously released and the time to drift from one lane to the next is timed. "Pull" is customarily tested by holding the wheel at whatever angle keeps the vehicle driving straight, and measuring the torque required to hold the wheel in that position. Car companies have thresholds for either drift, or pull, or both.

"Clear vision" is the term that describes how the steering wheel is centered during alignment adjustment. Clear-vision is almost exclusively dictated by how the front toe settings are done. A good practice is to set the front toe with the car running at idle speed so the power steering system is pressurized. The steering wheel is centered and locked in place with a fixture (any shop with a decent alignment rack will have this). Then the left and right tie rods are adjusted so that the total toe is equally divided between both sides. I would not remove the steering wheel to correct a clear vision problem. If you can't center the steering wheel with the above procedure, something is really out of wack and vehicle handling and vehicle stability control systems could be seriously compromised. BTW, Porsche recommends a calibration of the steering wheel angle sensor when the alignment is adjusted for vehicles with such electronic systems as PSM.

Anyway, drift/pull is not the same as clear vision (a "centered" steering wheel), and their cause/effect relationships are (in most cases) totally independent from each other.

Obviously, I haven't even seen or driven the car in question, the alignment values have not been posted, and diagnosing things through the internet ether can be speculative at best, but it sure sounds like the complaint here is about drift/pull, not necessarily clear vision.

(1) Don't even worry about the rear wheel alignment settings affecting the problem described here. Not rear camber, toe, or anything else. Rear alignment settings are important to sports car handling characteristics (especially camber) and to a certain extent tire wear. Rear alignment settings do not affect drift/pull tendancies or clear vision characteristics.

(2) Front toe will not appreciably affect how much a vehicle drifts or pulls. This might sound counterintuitive. When driving straight on a straight road the front tires attempt to reach equilibrium and take the steering wheel with them, with essentially equal amounts of toe on the left and right. So if the front toe was set properly, then the steering wheel will be straight as the car drives straight. But even if the total toe is way off, and/or with wildly different toe settings on the left/right (poor clear vision setup), all that happens is the steering wheel is off-center, but there is no drift/pull and the car goes straight without unusual steering torque by the driver! This assumes there are no other mitigating factors such as (3) and (4) below.

(3) The problem here could be front cross-camber. This is the difference between the left and right camber settings. I am fairly certain the car in this case should nominally have equal camber on the left and right. A difference of 0.1 deg (such as -0.1 on one side and -0.2 on the other) is probably not an issue for drift/pull. A difference of 0.2 (such as -0.1 on one side and -0.3 on the other) could be borderline. More than that, and I'd be suspicious. Make sure the alignment tech checks the camber settings and corrects any differential between the left/right as much as possible.

(4) The problem here could be the front tires. Make sure the tires are the same size on the left and right (sounds crazy, but you did say this car was fairly new to you) and that the pressures are properly set. Correct anything that's out of spec and perform a road test. Also, irregular tire wear or a tire uniformity characteristic known as "conicity" can cause drift/pull. Check both tires for irregular wear, particularly wear on one shoulder more than the other. You can't "see" other causes of tire conicity, so they have to be measured on specialized equipment--a Hunter road force balancer can give you some data. A quick test/experiment (even if the tires are directional) is to temporarily swap the left and right front tire/wheel assemblies from one side to the other-- if the drift/pull you had is now drifting/pulling in the other direction, there is your answer...one or both of the front tires. Perform all road tests on the same stretch of road, in the same lane, at the same speed.

(5) There could be a stack-up of things. A little front cross-camber might be combining with some front tire factor(s) and causing the drift/pull.

In summary, I would: Check the tire sizes. Properly set tire pressures and check for apparent front tire wear irregularities. Check and rectify any front cross camber. Temporarily swap left and right front tire/wheel assemblies. Doing so will almost always help you figure this out.

Good luck. Let us know.

--Brian