So I recently got the wheels on my brickyard red, 2006 350z powder coated white which obviously required removing the wheels off my car, and the tires off the rims.I jacked the car up myself, and set it on bricks in my garage. After they were finished, I took them to the shop to get the tires put back on the rims. At this point I didn't realize that the size of rims in the back differed from the front, and neither did the person at the shop. When I got home, I put the larger tire size on the back and the smaller on the front, and on my first drive I realized something was very wrong, at even 10-20 MPH my steering wheel was shaking terribly, like my wheels were going to fall off. We then checked sizes, and realized that the front were 18.5 and the back were 18.8, and that they had switched the tires on the passenger side so we had the wheels switched so they didn't quite fit properly which led to very bad shaking. So all the wheels were correct but the tires on the passenger side were still wrong. This was drive-able, but barely. Good enough to get to the shop where they switched them. However after we switched the tires on the passenger side, and everything seemed to be in the right position it still made the sound of what is similar to a flat tire or if something wasn't properly sized. Anything over 30 MPH and the one of the back wheels/tires feels like it's going to fly off. They were balanced at the tire shop aswell.

Sorry for the drawn out story, but I wanted to give as much as information as possible, I'm out of ideas on what could be an issue. If anyone has an idea please let me know, Everything seems to be in the right position but it sounds terrible, and feels very bad. Something is obviously very wrong

 

Few things it might be (in order of likelihood)...

1. Tires were switched side to side. (Front or rear) - tires take a "wear set" from front to back AND side to side. An inadvertent "cross rotation" (mounting rotation side to side) could have occurred causing irregular wheel rotation (driving rotation).

2. Check lug torque - although this is more unlikely since the tires/wheels have been on/off several times. HAND torque is required to 80-85lbs.

3. Wheel balance (although this is an extreme case.) Are these OE wheels or aftermarket? While powdercoating won't affect anything in a general sense and not to the degree you're talking, it's possible that if the barrels were PC'd, wheel weights might not be adhering well.

 

Thank you very much for your input! Yes, the wheels are stock, and as for the lugs, we thought we were fairly thorough with tightening, and we did double check them. However the tires could of easily been switched from side to side as we did not mark them. I guess there's no way of telling which ones were on which side, besides trial and error? And I assume it would behave the way I described, like a wobbly unbalanced feeling even at very low speeds?

 

 

Is there anything to do to avoid that? Is pressure washing bad for them or anything?

 

I was at a Z show several years the 350Z was fairly new, and a guy came up to me asking me why I thought his 350Z was driving so poorly, especially in the rain....after a quick look, I noticed his tires had been rotated, and he had his front tires in the back and the back tires in the front. On top of that, he was running the stock Potenza tires (RE040), which are directional, so the traction was horrible when you drive with their treads going in the wrong direction. I have the Rays forged rims on my 03, and the rims are identical, but the tires on the car, are not the same from the front to the back, and every tire I have run on my 350Z has been directional... the Michelin Pilots on there now are directional; as well.

 

Yes, it could easily be from the wear pattern (or "set" as I mentioned). If your alignment was off at any corner prior, you might have some uneven wear or "cupping" (early Z issue but not the '06) of the the tires that didn't show up in their original position but once moved to the other side, the wear becomes fairly obvious because as was noted above by onecoolee, the tires are now going against the bias/direction it was originally rotating.

How much is left of the tires? Might be a good time for a new set...

 

Yeah, the rear tires are fairly bare at this point, I almost survived this winter so I was just going to try to wait until next winter... I decided to just leave my car at a tire shop and let them figure it out, but I called them and told them that the tires could've been put back on the wrong sides, so hopefully they'll check that. Much thanks for your help though, hopefully this will be resided soon. Just want my car to drive normally again

 

Gotcha, yeah mine might just be a worse form of that, because if he's still driving it without it basically feeling like it's falling off then it must not be quite as bad as what mine is. But yeah I called the shop and told them that it's a high possibility that's the issue so hopefully it'll be a fairly easy fix. Thank you for the input!

 

Bare? As in less than 3/32nds? Just FYI, if that's true, the tire shop should have refused the business. Tires are legally dead at 2/32" and they could potentially be liable in the event of a tire failure or related incident - although the loophole is that it's "the customer's tire and its just a re-mount".

In any event, just get new tires since you need them. Save yourself the hassle and issues. "Wait until next winter"? Ouch. You do realize that tires are the only difference between you driving the car and sliding the car, right? Oh, and stopping...

EDIT: Just noted location..... doesn't PA have annual safety inspections? Would think that balding tires are a non-starter.

 

Shocked to hear that powdercoating weakens the OEM Touring V2 wheels, I thought only the chroming process did this.

As others have mentioned.
1) Make sure your 18x8 are in the front and 18x8.5 are in the rear (Assuming Touring V2 wheels).
2) If your tires are directional, make sure they are all setup correctly.
3) Sand any rust build up on your hubs & rotor hats as well as the mating surface for the wheels (That portion shouldn't have been powder coated).
4) Sounds silly, but make sure the cone side of your lug nuts is facing the wheel. I've seen people get the lugs threaded on backwards before! (Assuming Non-OEM lugs).

Cheers!
-Icer

 

To add on to this, you should be using OEM lugs with your OEM wheels. Aftermarket lug nuts will generally not fully seat the to the wheels.

Also, I assume the shop is just using an impact wrench, but make sure the wheel lugs are being torqued down without the full weight of the car on them.

 

 

Might want to wait on the spoiler and front lip if you need tires and possibly new wheels.

 

I actually did end up getting new tires then, so I should be fine with that