Looking for some expert advice - I just installed some fresh rubber on my TT. I've got 997 19" rims with old 235-35-19 PS2s up front and fresh 315-25-19 Nitto Invos in the rear. I have confidence in the shop that mounted and balanced the Invos.

When I put the tires on, I also installed a set of wheel spacers that I purchased a few months back. In the rear, I went with 1/4" (6.35mm) - I had planned to use the 3/8" (9.5mm) versions, but these spacers do not have a machined lip. They are completely flat on both sides, and I wasn't crazy about the amount of hub "rim" that was left for the wheel to mate to. I used extended lug bolts with these.

I also installed some ~1/8" (3mm) spacers up front. I used stock lug bolts with these.

Driving in to work this morning I noticed considerably more vibration than usual at highway speeds. Definitely more of a seat of the pants type sensation than a steering wheel feel.

Ideas?

Balance not quite right?
Spacers causing a problem?
Other?

Thanks,
Trevor

 

If the spacers aren't hub centric, they could cause a vibration.

Bent wheels, or improper balance could also be something to look at.

 

Trevor, I agree with ^. When I installed 7mm spacers in the front,it caused pretty bad vibration in the steering wheel at around 55mph. To make sure it's the hub rings, I'd suggest taking off the front rings and putting the wheels back on to narrow it down. If there's no vibration, you know for sure it's the hub rings. If there still is, it could be bad balancing (or maybe even bad tires).

If it's vibration from the rings, one procedure that I used that helped get rid of 95% of the vibration is that while you are installing your wheel (with the hub ring), with the wheel still in the air (no load), tighten the lugs in a star pattern in incrementally increasing torque (50lbs -> 70 lbs -> 90lbs - 110lbs) with someone stepping on the brakes. When I did that, it got rid of most of the vibration. Hope it works for you

Edwin

 

Hi guys,

Thanks for the input. The spacers are definitely hub-centric. Also, I torqued down the rears while unloaded. For the fronts, I hand tightened them, put some weight on them to keep them from spinning, then torqued them.

I'm definitely going to remove them as a first step in diagnosis. I'll keep you posted.

 

If the spacers are flat on both sides, then the are not technically hub centric. The spacers with the centers raised a little will make sure that the wheels are sitting perfectly center. I would suggest getting some HR spacers. They are worth the money. I have the same exact tire sizes you have with spacers on the back and I have zero vibration at any speed. Also, I have not personally used Nittos, but some on the forums would not recommend them. Personally, I have PS2 all around. It could be that the Nittos are compounding your problem. The 315 25 19 size is a tough tire to manufacture since the tire has such a low profile.

 

Good luck Trevor. As I think I've mentioned via email, if the spacers are totally flat it is pretty easy to get a vibration if you don't torque in a star pattern while the wheels are off the ground. It took me a couple tries on my old c2 to get the wobble out of a set of H&R non-hubcentric 7mm spacers I was running up front, but I eventually got it. Good luck.

 

So how can the spacers not be hubcentric if their inner hole fits over the stock hub ring and enough hub ring remains to center the wheels?

Scott - yeah, I remember you saying that. The rears were definitely torqued while in the air, but the fronts did have some weight on them. I'll diagnose this problem more shortly, but right now I've got an alternator / battery problem (see new post).

 

[quote=tbarcelo;2983348]So how can the spacers not be hubcentric if their inner hole fits over the stock hub ring and enough hub ring remains to center the wheels?
[quote]


If they are flat on both sides, then only one side can fit onto the hub. If there is a hub ring that the wheels goes onto, then I would say that it is your tires causing the issue and not the spacers.

 

Trevor, I had the vibration issue even though I too thought I had enough hub sticking out to "center" the wheel. (my 7mm spacers were h&r and were not "hubcentric" as they did not have an intergrated flange like the 14 mm spacers I was running in thear wich effectively acts as the new hub). The problem is that the amount of hub sticking out, even with 5 to 7mm spacers, is not enough to properly center if there is even a moderate amount of weight on the wheels before they are torqued pretty good in the air in a star pattern to ensure even torque. It also depends on the wheels and how they are made...some wheels have no problems centering on a small amount of hub, others need more. Good luck!

 

Cool, thanks Scott. Once I get the alternator back in I'll try that.

 

It was the tires. I removed the spacers and the problem was still there. My tire balance shop said that both of the new tires had severe radial runout. He was able to correct most of it on one, but the other still has it. I'm going to try and get replacements from DiscountTireDirect. Not sure whether I should try to replace them both or just one ...

 

Hi all,

I still appear to be battling this issue. I now have brand new, freshly balanced 235-35-19 Nitto Invo rubber up front to match the 315-25-19 Nitto Invos in the rear (about a year old). I am not running any spacers up front, but I do have a ~5mm spacer in the rear.

I'm still getting a pretty noticeable vibration (felt in the steering wheel) at highway speeds.

Some days it seems to be worse than others (and I really don't think it is flat spotted tires because it has been happening on consecutive days, lately, with high ambient temps).

Might this just be Nitto Invo tires? Worn suspension components? Something else entirely? Anyone have some good diagnostic ideas?

Thanks.