Hello, please tell me what you think, and I'm trying to upload a video too. I have had for a while now an issue where my steering wheel will not entirely center after a turn. Maybe some of this is normal for an S2000 but it seems like too much and it wasn't this bad in the past. I'm a technician and have checked literally everything including the alignment and tire pressures but suspect it may be due to the tires not being the appropriate type for this car. "Ultra" performance summer tires are equipped but not "max" or "extreme" performance.

Had this issue before, tried adjusting the steering rack guide screw to be looser, and this somehow fixed it entirely. Until I replaced all the tires with the current ones. Since then, rack adjustment has had no effect. It would best be described as the steering wheel stopping at 10 or 2 o'clock instead of at 12 under a typical 90 degree turn. The car will rarely straighten on its own without manual help. I'm out of ideas, so if anyone knows something please tell me. Thanks.

 

When new tires were fitted, did you also get an alignment?

What was caster set at?

I can't see tires ever causing this. But bad alignment would be first thing that comes to mind. It started after you got new tires, but its not the tires,its the alignment that was done at same time.

Even if you tell me you didn't get an alignment, I'd still say alignment. Like maybe they messed up, some tech assumed you were getting alignment with new tires, and went ahead and did it. But did it wrong. But they never told you it was done.

 

The rack guide wasn't loosened beyond the spec, I hope? Or you'll be doing a lot of wear on the rack.

S2000's just dont have a strong return to center like some cars do.

Things that can make it worse..

Modifications. Aftermarket lower ball joints with too much striction. Or suspension geometry changes.

Alignment settings. Got enough caster? Not too much camber or toe? Not just front alignment, but rear also.

Some tires just have less on-centering. Kumho V12 (for example) have a ton of tread squirm and may not center properly.

New parts.
Tires take time to wear in. New OEM ball joints may also have extra striction that takes some time to reduce.

Steering torque sensor settings.

Too much rack piston friction (though you confirmed you already checked this).

Are your tire pressures OK?

 

I did the tires personally and have checked the alignment at least thrice since (I do tires and alignments frequently at the dealership I work at so It is something I have little difficulty doing). I know that caster is extremely important with this car and can even be adjusted, and I have. However, I'm going to check again, I realize toe and camber matter a lot too. For a seemingly unrelated reason, I had a problem with my cars alignment in the rear when discovering the pass rear camber bolt was ruined and did not stay tight and this changed the thrust angle and caused pulling. This bolt has since been replaced. So I have had this particular car on the alignment rack multiple times.

 

Also check subframe alignment. Basically, loosen all 6 subframe bolts, stick pair of big screwdrivers into alignment holes, manipulate them around until both go through both hooes, subframe and body, perfectly straight up down and centered. Retorque subframe bolts.