First off, newbie to the forum here. Some of you may know me from the VWvortex, especially the Home Improvement board. In any event, I just picked up an '06 G35X (new) with Premium 3 for under 32K. The fun has already begun.

This is copied/pasted from another forum, so my apologies to those of you who may have already seen it. (Wow... first post here and it's a cross post? )

Here's the dilly:

Brand-spanking-new G35X. Zero miles. Steering wheel shimmy and overall vibs on the drive home. Brought it in two days later for a balancing which cured the shimmy.

Now with a tad over 1500 miles the car still has a slight vibration, almost a resonance, at certain speeds. 40 MPH, 70 MPH, not all the time. It's a similar feel to driving over a rumble strip, but not nearly as pronounced. Just an annoyance.

My tire pressures are all good, and there is no visible damage, but I think it's a bad tire. The dealer disagrees, says "It's an inherent characteristic of the high-performance all-wheel drive"... I have the service manager telling me that on my voicemail... priceless! The service loaner I drove (same car) did not demonstrate this "inherent characteristic", nor did the demo I drove before buying the car. Oh, and the AWD 2002 Subaru Legacy GT with 117,000 miles sitting in my driveway does not do it, either.

I'm meeting with an Infinity rep sometime next week to go over the problem. I am thinking about asking him to swap out my wheels/tires with the ones from the service loaner and give it a whirl. If that cures it, I want new wheels/tires.

So, before I meet with the rep, does anyone here have any other thoughts as to what the problem could be?

 

I have this same problem. I have no idea what it is. It does it even worse when the car is cold. Once it warms up it doesnt really do it till higher speeds.

 

I have over 30K miles on my X and have had no such experience. Sorry I don't have any suggestions other than you are being bull****ted by Infiniti.

 

^^ what Xman said, no problems here either.

 

I have on 05x. Starting around 16K, I too noticed a vibration. I brought it in, they replaced the final drive, put new rotors and balanced the wheels, all to no avail. Infiniti Tech then said that a slight vibration is NORMAL for all G35x's. I'm not convinced. They did however lower the RFD (Road Force) of the tires which made a HUGE difference. I suggest asking your local Infiniti Service about lowering the RFD.

 

was the loaner an AWD or RWD? most loaners are only RWD, in that case, could be a prolem that only exists in the G35X...

 

The loaner was an X. It was smooth and quiet.

Now, what in the world is "Road Force"? This almost sounds like a muffler bearing, if you get my drift....

 

OK, it's like this... If the dealer had a reason to remove one of the wheels, it is quite probable that they didn't put them back on right. My dealer once did an alignment for me and put the nuts back on so tight, I had to use a 3 foot breaker bar to get them off. (Good thing I did because there is no way I could have gotten them off with that little wrench in the tool kit). Anyway, if they f**ed up and put the wheels on without being careful to follow the bolt sequence, your wheel may not be on straight. Take them all off and put them back on yourself carefully following the right sequence and torque specs. I would be willing to bet that fixes everything.

 

The way road force was explained to me (because i had never heard of it either) is that its the way that the tire is mounted on the rim. So for me, most of my wheels had an RFD of 35. After they were done re-mounting the tires, they got the RFD down to about 4 or 5. HUGE difference in the way it drove. I'm not sure how the measure it, i wasn't there to watch them, but thats how they explained it to me.

 

This is the best I can find for a definition of what road force is...

 

Find a Dealer with a Hunter "9700" balancer.
http://www.gsp9700.com/

 

OK, this makes sense. My dealer stated that they use a balancer which simulates load on the tire. I'm sure they just dumbed-down the "road force" explanation.

Here's some encouraging news - I jacked up the car in my driveway this morning and rotated the wheels, front to rear. I then hand-torqued the lugs to 80 ft/lbs per spec. (BTW, 1 lug on each wheel was cranked on, while the rest felt to be within spec) The test drive showed a dramatic change.

The car NO LONGER vibrates at speed. Nada. I used to feel the buzz right around 70, and it is now completely gone. BUT, there is now a slight shimmy in the steering wheel that starts around 50 and continues through 80+. AND, roadnoise has diminished.

I am now 100% certain that there was a problem with one of the rears which is now one of the fronts. I am very relieved that I have isolated this problem and that it has nothing to do with the car.

I plan to bring it in to the dealer sometime next week and show them their precision balancing work, then insist on at least two new tires.
If all else fails, I can bring the car to a tire shop near where I work that does very detailed work. He'll probably be able to get the tire warranty honored for me, too.

I'll post the end result after embarrasing the service department.

 

My G35x has never had a vibration, not have the loaners (all G35x at my dealer). I'm sorry they gave you that BS explanation in yoiur first post. That has not been my experience with Infiniti. They might give you a new tire, even though that is usually a separate warranty through the tire maker. I had a bleb and the service manager, who has known me for years through now my 3rd Infiniti saw me in for service and asked how things were. I told him OK but they said I needed a new tire and to go to a tire dealer. He basically said "let me check" and came back and said they were putting on the tire for me. Good luck, and enjoy the car.

 

It's definitely the tires. And sometimes, no matter how many attempts or the method of balancing, tires will still produce such vibrations. Genereally it's a manufacturing defect in the tire itself.

It does suck, but it does happen. I suggest requesting a full tire service, and if that doesn't fix it, then request new tires.

 

I agree. It was also a problem that Tom Martino (The trouble shooter) had to help a customer deal with. It was just the tires, and new ones fixed the problem. It was different brand of car though.

My 06 X defiantely has not had any of those problems at all. Hope you get it worked out soon.