Howdy,

I was hoping the wheel/tire experts here could point me in the right direction. I have an '06 G35 sedan (non sport) and purchased a set of takeoff 19" M35 sport wheels with Michelin Pilot Sport PS2 tires that have good tread remaining. I wanted more grip than the all season tires I had before plus a more aggressive look.

I bolt the wheels on and take it for a test drive. I noticed that when I accelerate and lift the throttle the car starts shuddering, from mild to serious-the-wheels-are-falling-off-oh-my-gawd depending on which time I try it. It will shiver from time to time when cruising. If you've ever driven a 1 ton pickup that's the kind of feel one gets, though the ride is fairly smooth the rest of the time, so it's not just the shorter sidewalls.

I am not as far as I can tell getting normal vibration like with unbalanced wheels/tires. The seller was a reputable tire shop and claimed they were balanced and tested and I tend to believe that.

Questions?

1. Do I need to simply have it aligned as this is a pretty significant change from the normal wheels?

2. They didn't feel too much heavier than the stock wheels, but is it an issue of the mass overwhelming weak stock shocks?

3. Are these unidirectional tires and I just can't see it on the sidewall? Would that cause this?


Obviously if I add lowering springs it'd need aligning then, but I want to make sure they will be trouble free before dumping more money into the car.

Thanks. I have lurked a while and as a former BMW owner have to say this is a far less douchey forum.

 

Put the original ones back on to make sure it's the wheels/tires. If it goes away, then I'd suspect the wheels/tires are unbalanced.

Other than the wheels being installed incorrectly, (ie... using the wrong lugs, not tight enough etc..) I don't see what else it could be.

Dont the newer Infiniti wheels require different lugs than the older ones? ie.. thin flat shank vs the tapered shank on our older ones?

 

are you running spacers on the fronts? you should need to, to clear the suspension arms. your tire might be hitting.

 

Wow, I guess I got some bad info that it cleared w/o them and didn't check. I'll go take a look.

I'm still wondering why I feel it after hard acceleration and not just coasting down the road.

 

Yep, the tire is snugged up against that suspension arm. I'll get some 10mm spacers to be sure it clears, unless someone can confirm 5mm do the trick for my car.

managed to find the link for the spacers here via the search function. Thanks

 

nice, glad to see i could help. i used to run the 19" M35/45 sport rims back in the day, 5mm will clear BARELY!!! just go w/10mm and do it all around to keep the wheels all looking flush w/each other.

 

thats odd, if the tires were unbalanced the vibration would be felt most crusing at high speeds

 

^ yea usually around 60-70mph

I didn't know M wheels didn't clear without spacers either.

 

Is it possible the inner bore of the rims is different than stock? If so and you're not running hubcentric rings that could cause your issues.

 

http://cgi.ebay.com/ebaymotors/73-1-...#ht_2751wt_939

they are all the same

 

UPDATE:

Ok, well the spacers finally arrived and I got they and longer studs installed w/o issues. They come with hub spacer rings that look pretty precise to me. (Ichiba 10mm spacers). The front tires now clear the suspension arms.

Get in the car, and the same thing is happening. When I slowly accelerate it seems ok, but if I accelerate briskly when I LET OFF THE ACCELERATOR I get the car shuddering. It again smoothes out as I coast back down.

The overall tire diameter is within about 1% of stock, so I can't imagine that is causing some sort of differential or abs type issue.

Any other ideas on what the issue is? otherwise I'm going back to stock as I don't care to play tire/wheel shop roulette on who will and will not refuse to deal with spacers.

Thanks for trying.

 

i know i experienced shudder w/ aftermarket wheels but a good, precise balancing and new hubcentric rings cleared up everything. you sure the M35 wheels aren't bent??

 

I can't say they're not bent, but it was an ebay seller with a good rep and lots of feedback and they claimed they were balanced and tested. Also I have to think that if the wheels were bent it would shudder all the time, not just after accelerating and letting off the gas.

I'm going to go out and test it some more to see exactly what speeds, conditions etc it occurs at. My problem is getting a shop to fix any issues with spacers on. I've had them before on a BMW and had 3 shops (dealer, two tire places) refuse to even sell me tires till I removed them, due to liability concerns. And of course in this case you can't remove them for clearance reasons.

 

also, just as reference, when i got my 19s i bought them brand new and they were "balanced" at the shop. i'd experience shuddering intermitently, when i'd let go of the gas only on the freeway, around 60ish miles per hour. it was only until i had them rebalanced at a different shop with a more newer, more accurate balance machine that all the shudder was eliminated. all balance machines are not build the same. might be worth a shot.

 

Thanks, that's a good point. I am just hating the idea of dumping more and more money into what I thought was a cheap upgrade.

I have to correct myself. It was shuddering after accelerating, but after more testing I see that it starts shuddering at 50mph no matter how fast I get up to that speed. So I guess it could be the wheels after all.

I guess I will go put the original wheels back on, one at a time, to find the culprit.