Vibration issue, tire related?

[SSLance]

I've been slowly but surely over the years chasing down every single little vibration issue on my car to make it as smooth as possible at highway speeds and I've got it pretty dern good now...but I'm still fighting one thing and I'm stumped over what it can be.

So I'm posting this question to see if anyone else has an issue like this and if it is common or unusual in my case.

When I take my car out of the garage and go down the highway, initially it'll have the typical flat spot feel from the tires sitting in one spot. It generally only takes about 3 or 4 miles of highway time for that to go away though...then the car is super smooth wherever I go with it. There is virtually no vibration at any speed when the car starts out cold like that.

But say I drive it to work, and it sits in the sun all day...on the trip home it'll have a shudder that feels like it's coming from all 4 tires between 60 and 70 mph. I can drive through it, or raising or lowering the speed just a bit will make it come or go, but it'll settle back in and not go away. It's not bad enough to make the rear view mirror unusable, but it is certainly noticeable. I first started noticing it on the way home from an autocross event, it scared me pretty good the first time because I thought I broke something in the rear end. But I drove the car again a couple of days later and she was smooth as silk again. The shudder only happens after the car has sat outside in the heat for a while after the tires have been heated up.

It is definitely tire or drivetrain related, pushing the clutch in and coasting doesn't change the vibration at all. and I feel it in the steering wheel and my butt, so it feels like it's comes from the front and the rear. Is this just a trait of 200 tread wear performance tires? Do the rest of you that run a high end sticky street tire have this happen as well?

All of my wheel bearings are fresh and tight, the Falken 615Ks have about 750 miles or so on them, everything else on the suspension is tight and fresh and even the rear axle and clutch have all been freshly rebuilt with no change in this attribute...it almost HAS to be the tires themselves right?

And I'm okay with it...as long as I know that's what it is. If there is something I can do to help it I'm in, or I can just deal with it.

[Sieg]

The last two sets of Bridgestone tires on my Tundra pickup will flat spot from sitting. It takes about 10 miles for them to make themselves round again.

Haven't noticed the issue with the NT05's on the Camaro.

[Vegas69]

It's been some time since I had Falkens on my BMW but I was less than impressed with them from a drivability standpoint.

[SSLance]

I should add, if I leave my car in the garage at work, and drive home that evening, it's fine. It only happens when the car has been sitting out in the sun\heat for a while. And it does not go away until the car has been parked back inside and cooled off.

I guess I should start checking the tire pressures and tracking them to see if they change drastically before or after this occurs.

I know i'll bleed 4-6 PSI out of them during an autocross event so they are low after it sits for a while before the drive home. but once home I fill them back up and they stay like that until the next race.

I LOVE the way this car handles on these tires, they really are amazing. And if this is just a trait they have, I'll deal with it. I don't think it's damaging or anything like that. Just trying to get the ride as Rolls Roycey as I can get it. :)

[Track Junky]

First off, before I let my car sit I always over inflate the tire a bit so that they don't flat spot. If your vibration is wheel balance related, I dont know about auto cross, but under road race conditions the tire will slip around the wheel causing an imbalance.

[SSLance]

Just curious, about how much extra air do you put in them when you let it sit for a while?

I've had tires that flat spot when sitting before and these do that as well, but that goes away very quickly. What I'm experiencing and describing now happens after it sits outside in the sun for a while and does NOT go away after driving it.

[Track Junky]

Tires I currently use I run at 30 lbs hot. I inflate to 36 lbs when car is sitting in the garage.

[Formula43 Wheel]

It could be tire related, but could be many other things. The odd thing is it is not constant.

You could try switching the tires from one side to the other and then back, because they're directional.

Check the sidewalls for any odd bulges, a belt separation that will get worse over time. The expensive part would be to replace the tires completely.

Do you feel the vibration in the steering, seat bottom or both? If from the steering wheel it's coming from the front, seat bottom, than the rear.

This is a difficult vibration to find if it isn't tires.

Good luck!

[SSLance]

The vibration became consistent so I began chasing things down again tonight. Found a loose axle bearing in the driver's side rear. Pissed because it's a brand new part, just a couple weeks old but happy that I found it and it makes sense. Not knowing is worse.

I'll get a new bearing ordered tomorrow and get it swapped out later this week.

[Che70velle]

Lance, I'm curious, what bearing manufacturer?

[Sieg]

The vibration became consistent so I began chasing things down again tonight. Found a loose axle bearing in the driver's side rear. Pissed because it's a brand new part, just a couple weeks old but happy that I found it and it makes sense. Not knowing is worse.

I'll get a new bearing ordered tomorrow and get it swapped out later this week.

Nice catch :thumbsup:

Lance, I'm curious, what bearing manufacturer?
Well............we're waiting. :D

[SSLance]

Let me give the seller the chance to make it right before outing them. :)

Things happen, how you react to things happening is different though.

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[SSLance]

I now feel okay about calling them out. I ordered the bearings from Moser on 05/12/2014. I installed and drove on them the first time on 05/16/2014, have put 270 miles on them including 4 runs at one autocross event. Apparently Moser buys their bearings from Green Bearing Company and they do not come with any warranty whatsoever. If I want I can send the bearing back to Moser and they will try to get a replacement for me.

OR...

I can pick up a different bearing from a local Napa for $59.00...I believe it's an SKF bearing. According to Moser it's a better bearing but does not have the O-ring seal like the cheap arse Green bearing...

http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Wheel-Bearing-Rear-Wheel/_/R-BRG88128RA_0297815522

Or Auto Zone has a Timken

http://www.autozone.com/autozone/parts/_/N-5yc1s?itemIdentifier=766295

And O'Reilly and Advance Auto have a Federal Mogul National

http://www.oreillyauto.com/site/c/detail/BCA0/88128RA.oap?pt=03337&ppt=C0362

Advance is $39.99, everyone else is about $59.99 for one. Moser charged me $65.00 for a pair...

I dont' care about the money, I want a quality bearing. One would have thought I WAS buying a quality bearing from Moser themselves... Shame on me for trusting them.

[Che70velle]

Lance, I certainly wasn't trying to get any bad vibes out here for a particular bearing company. It's a rare deal to see this happen to a rear axle bearing, is only why I was inquiring. A rear wheel bearing SHOULD easily go several years with little to no noticeable wear.
I'm a believer in Timkin bearings. No affiliation what so ever, but it's a quality bearing that I know you can trust. It's the only bearing I ever bought for my race cars, and as pictured in my build thread, I rebuilt my 12 bolt for my chebelle with Timkin.
I found my local Napa beat everyone's price on Timkin. Call them, before you settle on the internet pricing, although if it's on the internet, it must be true...
Bonjour!

[NAPA 68]

PM sent

[SSLance]

This had to be just a fluke deal, the bearing started failing in less than 100 miles. The outer race is so loose i can wiggle it back and forth in my hand now that the axle is out of the housing.

There was a little bit of gear oil between the seal and bearing and it was clean, no metal in it...and no metal inside the axle housing. I'll get the new bearing pressed on tomorrow and then keep a close eye on both of them for a while.

Thing is, I now know exactly what it feels like when it starts to go if they do again.

Moral of the story is, if something doesn't feel right, it probably isn't...check it out.

[Vegas69]

Perfect time to go to those tapered bearings.:D

[SSLance]

No...no it is not!!! :snapout:

[SSLance]

Check out the movement on the outer race...

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This bearing started to fail in less than 100 street miles. Here in the first autocross lap I ran on it you can hear it already failing...Go to about 34 seconds in

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[dontlifttoshift]

Make sure the bearing retainer isn't bent. That may be the root of your problem.

[SSLance]

Which bearing retainer are you talking about? Are you talking about the keeper or "wedding ring" that is pressed onto the axle to hold in on?

Or the plate that bolts on the outside of the brake backing plate that tightens the axle to the housing end?

The prior bearings had over 5,000 hard miles on them and were both just starting to get a bit rough feeling when turning them, there was no side to side movement to them at all yet. I replaced them just because. I changed nothing else, the axle tubes have billet ends on them that look fine and the axle themselves are straight and true. Here we are using a lathe to turn the old keepers off of the axles...if anything was out of whack it would have shown here.

https://lh4.googleusercontent.com/-za1MsdqK1xs/U3U5t_-frxI/AAAAAAAAOl4/GLtSXJQFOjM/w999-h563-no/IMG_20140515_125928_305.jpg

https://lh5.googleusercontent.com/-baa1UstIADc/U3U5sOzXz0I/AAAAAAAAN10/WsREzOBsG8E/w999-h563-no/IMG_20140515_130651_548.jpg

We'll double check the trueness of everything axle related later on today when swapping the bearing.

[dontlifttoshift]

Or the plate that bolts on the outside of the brake backing plate that tightens the axle to the housing end?

.


This.

[Vegas69]

My moser roller bearing set up had that much play as well. From the day I first touched them to the day I swapped them for a tapered bearing. I don't think it's your shimmy. I do think it is why your wheel is rubbing your shock bracket. When I built my car, wildwood and moser weren't on the same page and there wasn't proper preload on the roller bearing. They fixed it after I made them aware. Make sure your bearings are properly preloaded. Moser should have that spec.

[SSLance]

So much smoother now... :excited:

This is what the inside of the Green Company bearing with 270 miles on it looks like.

https://lh4.googleusercontent.com/--mP_QV7d6_c/U6IaiKuKOpI/AAAAAAAAOu4/8XM5RK9Q7l8/w1215-h685-no/IMG_20140618_164640_196.jpg

That is metal from the outer race that has turned the blue colored grease dark.

Just for comparison, this is the inside of the Federal Mogul bearing that came with my axles 5 years ago that have about 5,000 very hard miles on them.

https://lh3.googleusercontent.com/-8wtImSX883Y/U6Iak_34qsI/AAAAAAAAOvE/f_mRPMgqYPg/w1215-h685-no/IMG_20140618_165634_438.jpg

They still didn't have any play in them but were a little rough feeling when turning.

The new Federal Mogul bearing also turns much smoother and easier than than the Green Company bearing it replaced. I'll probably do the passenger side as well soon just because.