Alignment Issues

After I changed the rear tyres, my steering wheel has gone slightly to the right, maybe by about 2-5 degrees. I have tried rotating the rear and front tyres, and done a 4 wheel alignment 3 seperate times. I have access to a 4 wheel alignment machine, so have done 2 alignments myself and know that it was set up perfectly each time. I also took it to another alignment shop to make sure it wasn’t my machine. Has anyone had a similar issue with their cars?

I don’t understand the rotation comment, most performance tires are directional, so the rears shouldn’t swap and the fronts are different so front to rear is out too. I’m getting pretty old now, so maybe things have changed or I’m misremembering, it’s possible . If it changed the steering wheel geometry, I would be inspecting the suspension points but even that doesn’t make sense because I would expect the front suspension to change the steering wheel.

Pretty sure my Michelins have an outside and inside but not a defined rotational direction, so side-side rotation would work. Anyway you only changed the rear tires? No chance you bent something doing the job? And you noticed the steering shift right after the tire change but before you did the realign? Man that's a weird one.

Not sure why it would change with the tires , but wheel off center is usually a slight adjustment to tie rods.

I have done a 4 wheel alignment myself twice, and had it done at another shop to confirm my machine is not faulty. Each time starting at the rear, adjusting camber and then toe, then going to the front and adjusting camber and the toe. Then for good measure I went back and checked the rear and then front again. I also made sure the steering wheel was straight at various points throughout this. Also note that I had the steering wheel locked and the brake pedal pressed while doing the alignments.

Not weird really, If the rear end is out of alignment, the front end needs to compensate for the car to go straight. However, it will dog track until the rear end is brought back into alignment. If all four wheels are properly aligned and the steering wheel is off center, the tie rods need to be adjusted.

My 2008 cayman S rear tires are wider than the fronts. So I cant rotate front to rear. Yours are the same width?

[Image-only or quote-only post; no author-written text.]

has nothing to do with tires . Sit in the car while aligning it and it’ll be fine. Had the same problem. Drove my alignment guy crazy until we figured that out

Some clearifing question that might help: 1. Does the car pull to one side, particularly on a highway? Or is the steering wheel simply off center? 2. When follow-up alignments were performed where any adjustments needed/made, if so what? 3. Did alignments include verification of the rear thrust angle? 4. When jacking up the car to initially remove wheels, how/where did you position the lifting pad? Any chance you caught parts of the rear suspension or frame structure?

The car needs to be balasted during alignment to match a full tank of fuel. That can make a difference if it’s forgotten

I meant I swapped the tyres left to right. All Caymans (and 911s I believe) have staggered front and rear wheels.

The car tracks dead straight at high speeds. I've attached a photo of the report for the most recent alignment (approx 1 month since the previous alignment) I'm not sure what you mean by verifying the rear thrust angle, but the rear camber and toe were checked every alignment. When jacking up the car, I put the jack on the transmission mounts and left axle stands on the jacking points for the day.

My alignment machine specifies that I fill the tank and not to use ballasts. I'm not sure what the second shops machine specified, but since they didn't use ballasts I would assume it was the same.

I concur with gubi, "...make equal-and-opposite adjustments to the front tie rods to get the wheel centered..."

You're probably fully aware, but I figured I'd throw this in for completness... Given your car has "tyres," you're driving on the left side of the road. Roads are typically crowned so that the water runs off left and right. When you're driving on the left, you're driving on a slightly leftward facing surface, which means you'll need to steer the car slightly right to compensate. Maybe this went unnoticed for years, but when you changed tires you paid particular attention to potential changes and picked up the slight right compensation that you never noticed before.

Initially I thought the same about the road camber being the cause, but even on perfectly flat roads (or driving over the lines in the middle) the wheel is still slightly angled. When driving completely on the right side of the road, the roads camber can cancel it out depending on how much camber it has. The amount of angle the steering wheel has in conjunction with these road camber tests can't really be attributed to just the camber of the road.

One other thing I'd check (and I don't think it's your problem but it should be easy to check) is if the steering wheel is properly centered to the rack. There should be two holes near the input to the steering rack that line up with a pin when properly centered. I think a plastic shear pin is used here to hold things aligned during install. Worth a confirmation I guess. If that's off you'd want to move the steering wheel a spline to get it aligned. It's possible someone R&R'd the wheel slightly off at some point, though why you'd see issues with a tire change I dunno. The other long shot thing to check would be a broken belt or similar in the new tires . Spin the tire and watch the tread for any non-uniformity in diameter.

For anyone encoutering a similar issue, here was the problem: The bearings/bushings in one of my front shocks had worn out, causing the piston rod to move and flex slightly. Found this out by jacking up the front of the car and levering the wheel up and down which allowed me to see the play. I would guess that when I adjusted the front toe, it was just taking up the slack in the shocks rather than actually changing my alignment. I have no idea why I can't feel this while driving though. I've ordered new shocks and hopefully thats the extent of the issue.

I don't know what it is but Thrust Angle is part of doing rear alignment. Just had my done and it is 0 degree Don't know what that would have to do with your problem Agree with post above me, adjust tie rods to straighten the wheel. Car goes straight. Only problem is the steering wheel position. Stop looking for aq problem that doesn't exist.

Thrust angle is basically just the difference in toe between the left and right wheels. This was adjusted during every alignment both I and the other shops did. the issue I’m having is where my wheel is angled to the right while driving straight, and when I adjust the tie rods there is absolutely no change to the angle of the steering wheel. My front right shock is the only thing I can find with my suspension or steering to be worn, so I’ve ordered two and will update if this fixes the issue. My best guess as to why the shock is causing this is that the shock does from being straight while under no load (during the alignment), to almost being the shape of a banana while under load (while driving), which causes extra negative camber and toe in.

Hard understand how you can move true rods without the wheel changing

You mentioned that you changed the tires , were they replaced or moved to different positions on the car? Since the only thing that changed was the tires it is most likely that is the issue. One or both of the original tires may have had a wear pattern that caused the car to track slightly differently than it tracks with the current tires , requiring a small change in steering wheel position to compensate for the tracking change.

Replaced all 4 tires