First post here, just bought a nice '04 G35 coupe. Having one issue though.

The (non-Infiniti) dealer I bought it from had put on 4 new Bridgestone Potenzas (nice, right?). Car has the original 17' wheels. When I got the car home, I noticed that one of the two larger tires was on the front right position. Since the two rears are supposed to be bigger than the two fronts from what I've read, I moved this one to the rear so the sizing was now correct. However, now there is a steering wheel vibration that starts at around 65mph and gets worse as speed increases. Since the rear rim sizes are supposed to be different than the fronts, from what I've read, I'm wondering if maybe they also mistakingly put the wrong tires on the wrong rims? Or is this not possible? Would the bigger tires not fit right on the smaller rims and vice versa? I also read that there is some kind of pin on the front brakes to prevent the wrong wheel size from going on. So how did they get the big one on the front when they first put the Potenzas on?

Not being the most mechanically inclined guy on the block, I'm all confused about this now. I'd rather have a particular tire store that I trust fix this mess, but I want to make sure I give them the right instructions as well. Should I just have them take all of the tires off the rims and start over? Maybe just need a re-balance? Any suggestions? Thanks

 

Are the 17" wheels staggered? (Wider in the rear than the front)

They could have mounted bigger tires on the fronts, even though they were skinnier wheels. the tires would just be a lot meatier.

I'm not sure on the 17's but maybe the vibration could be because you now have two different wheel widths in the rear and in the front, as opposed to having the same widths for the front, and same for the rear. (That's if the 17s are staggered)

 

According to the owners manual, front wheel size is 17x7.5 and rear is 17x8. I'm not familiar with wheel terms but I imagine that would mean staggered. Something is telling me the fix for this is just going to be to take them all off and start over.

 

So yes they are staggered.

All wheels are 17 inches in diameter. The fronts are skinner at 7.5 inches wide.

The rears are 8 inches wide. That is staggered.

So instead of having

Front left & Front right = 17x7.5
Rear left & Rear right = 17x8.0

You now have

Front left = 17x7.5 ----- Front right = 17x8.0
Rear left = 17x8.0 ------- Rear right = 17x7.5

Switch back the wheels that you changed and see if that resolves the vibration.

 

Thanks. I actually had it up past 70mph before making the change I did, and it was not vibrating at that time. So the wheels may be in the wrong positions now (front right and back right need to be swapped again) but also the tires on each wheel need to be changed (so that the larger tire ends up on the larger rim in the back).

 

So what I'm getting is

The tires in the front and rear do not match? But if you switch one front tire to the rear, then it will be perfect?

They should not have mounted different widths of tires in the fronts and backs.

Luckily, swapping the tires shouldn't cost more than $50.

 

The way the car came to me, one of the larger tires was on the back left (correctly) but the other was on the front right (incorrectly). However, I'm thinking they had both of the larger wheels together in either the front or back. When I tried to correct the tire size location problem, that's where the vibration came in, because front now has one big and one small rim, as does rear, even though the tire sizes are in the right spots now. Confusing, I know!

The tire shop I used had mounted and balanced a set of summer tires on another one of my cars recently for $60 so that should be the worst damage in terms of getting this straight. Other than the annoying vibration, could I be harming the car by driving it like this until its fixed? I'll keep the speed below what causes the vibration, in any event. The car is not all-wheel-drive so I'm thinking there isn't much harm now.

 

Whoever installed those tires is not too smart! Take your car to get an alignment, can't believe they aligned your car with different tires in the front! A lot of shops are just too used to rotating tires when the car goes in for service, which is probably what happened to your car. They rotated the tires, then the car started vibrating and they had it aligned with the wront tire up front.

 

I recently had my winter tires swapped for my summer tires (OEM 18"). They called me to come pick up the car (had to leave it a while, they were busy), so before I went in I checked the tires out.. one front 225 the other 245, same with the rears. I just walked in and said "You put the wheels on wrong... go fix it please". I told them they were staggered when I dropped it off

 

You were able to swap your front tire/rim to the back? I can't do that on my '04...... there's a little peg on the hub which fits into a notch in the rim and prevents you from installing a tire from the front onto the rear of the car.

 

Yeah, I'm surprised some of the smaller tire shops seem clueless about staggered tires! A dealer doing this is even worst, it even says on the service manual that tires on coupes should not be rotated. But yeah, when I had my Mustangs sometimes I would go to a tire shop that is about three blocks from my house and one of the guys there once said to me "you shouldn't have different tires in the back, what if you have a flat?"

 

Coupe tires/wheels are not supposed to be rotated and someone got the wheels mixed up. If your OE 17" are like my OE wheels were you have a bolt inside the wheel that is intended to only work and line up on the front! Go to your local tire shop and have them switch the tires only and rebalance, that should solve the issue you're having....Gary

 

The vibration is most likely from the rear wheel not being flush on the front hub thanks to that useless bolt, check to see if there is a gap. If the wheels were balanced properly there shouldn't be any vibration despite their location on the car.

 

Yeah, I think that gets removed often when you get aftermarket rims put on (in this case, my winter rims). But they are normally there.

 

The vibration could also just be the tire needs to be re-balanced. Some lazy shops don't properly balance tires for the rear because you can't notice it as much as your wheel shaking.