Wheel Question Again... the saga continues

[Racinfan83]

Ok as some of you know I have had a vibration since I got the car. Multiple balances, new tires, checked car over several times both by myself and the best Vette tech in town, still has vibration. The Vette guy thinks problem is because the aftermarket "OE Wheels" are not hubcentric. And they are loose on the hubs by about .036-.038. I finally got ahold of a guy at OE Wheels and this is part of what he sent back: The only thing I can think of is that maybe the hub on the true c4 ZR1 is smaller in diameter than the base Corvette of that year. We would not have any hub rings for that because the center bore on the wheel is 70.7 mm. I don’t know if there are any hub rungs even available in the size that you indicated."
Is that a true statement? My hubs measure 2.75. Wheel center bores are 2.786 (70mm and 70.7mm). I have been trying to Fab some shims that fit inside the wheel bore, tried .020 aluminum last night and its too thick. Gonna see if I can come up with some .016 stuff and try that. Any other ideas?

[GOLDCYLON]

Ok as some of you know I have had a vibration since I got the car. Multiple balances, new tires, checked car over several times both by myself and the best Vette tech in town, still has vibration. The Vette guy thinks problem is because the aftermarket "OE Wheels" are not hubcentric. And they are loose on the hubs by about .036-.038. I finally got ahold of a guy at OE Wheels and this is part of what he sent back: The only thing I can think of is that maybe the hub on the true c4 ZR1 is smaller in diameter than the base Corvette of that year. We would not have any hub rings for that because the center bore on the wheel is 70.7 mm. I don’t know if there are any hub rungs even available in the size that you indicated."
Is that a true statement? My hubs measure 2.75. Wheel center bores are 2.786 (70mm and 70.7mm). I have been trying to Fab some shims that fit inside the wheel bore, tried .020 aluminum last night and its too thick. Gonna see if I can come up with some .016 stuff and try that. Any other ideas?

Do you still have your stock wheels? If so you could mount those to rule out bad hubs, warped rotors, problems with your Wheels or something else etc since you have already ruled out alignment and balance issues. PITA but would answer the mail on the hub centric issue if there is indeed a difference or as suggested spacers. My son had to go to spacers due to this problem on his Mustang GT when moving up to 20inch Foose wheels. The spacers solved his vibration problem. That and and removing the factory lockwashers Ford had placed on one of each of the wheel studs to retain the rotors in place which would not allow the wheels to get to flush with the mating on the back side of the wheel to rotor hat. He since has bailed on the Mustang and is throughly enjoying his Scion FRS. The kids love those.

[hiperf406]

I had a similar problem - Discount Tire balanced wheels several times & even replaced both rear tires. I checked the rear wheel bearings & I found one to be slightly loose so I changed both out & that seemed to fix the vibration. I had just put different rims & new tires on my car.

[GOLDCYLON]

I had a similar problem - Discount Tire balanced wheels several times & even replaced both rear tires. I checked the rear wheel bearings & I found one to be slightly loose so I changed both out & that seemed to fix the vibration. I had just put different rims & new tires on my car.


Yep I had a vibration issue after my last thrust angle alignment. Replaced a loose axle hub and it was like driving a new car. Ended up replacing the other side when I could hear a clunk when backing up and you could hear the hub when running on the freeway. Went with a NOS OEM unit and happy with that result. Next time will try a Timken a few folks hear have reported them to be good replacement rear axle hubs

[Racinfan83]

I have a set of factory wheels - but like an idiot I had the old tires mounted on them for "winter tires" thinking the new tires were gonna fix the problem. So to check that option would be another chunk o change to swap them all around again. Got some aluminum tape so gonna try that next...

[batchman]

There is no problem with using your wheels as lug-centric as long as they're tapered seats with conical lug nuts. My complete and utter total abuse with slicks has proven this time and again as my CCWs have a huge receiver and are No.Where.Near hub centric.

I am really surprised to hear hub play turn into vibe as I run my hubs next to death but of course I never take this car on the highway either...

I will say I have had quite an interesting variety of hub snout sizes among all the hubs I've changed. I still believe all the hubs found today are from the same factory in China and you get whatever snout/flange/label/etc were rolling around the bin at the time.

Meanwhile, did you try just changing to your factory wheels/winter tires? Will help pinpoint whether it's wheel/tire or car...

If it's tire/wheel I will guess bent wheel, if it's the car I'll guess bent axle or maybe (as above) bad hub.

Best,
- Jeff

[Racinfan83]

Yeah I tried bolting on the factory wheels with the bad tires. About the same vibration with them as I have now with the aftermarket wheels and new tires. But of course - the tires that are on the factory wheels failed two "road force" balancers - so that vibration could be the tires themselves?? I should have left the old tires unmounted until I figured this out I guess - then it would only cost me $100 to switch em and try new tires on factory wheels..:rolleyes:

I do have the correct angled lug nuts. The nut seats are angled too - looked at em on the one wheel I had off last night and they are somewhat scarred up. But I would still think they should center the wheel? I've read a bunch of stuff and pretty much the concensus is that hub centric is best??

How do I check for loose bearings in the rear? Wouldn't think so with 19k miles but I guess its possible. No noises or anything that I've heard...

I got some "500 mph tape" that they use as temp patches on planes. It is aluminum and thicker then the "foil tape". Gonna try that tomorrow and see if I can get them tight and go from there I guess. This has been THE MOST frustrating thing with this car...:mad::mad::mad:

[USAZR1]

Yeah I tried bolting on the factory wheels with the bad tires. About the same vibration with them as I have now with the aftermarket wheels and new tires. But of course - the tires that are on the factory wheels failed two "road force" balancers - so that vibration could be the tires themselves?? I should have left the old tires unmounted until I figured this out I guess - then it would only cost me $100 to switch em and try new tires on factory wheels..:rolleyes:

I do have the correct angled lug nuts. The nut seats are angled too - looked at em on the one wheel I had off last night and they are somewhat scarred up. But I would still think they should center the wheel? I've read a bunch of stuff and pretty much the concensus is that hub centric is best??

How do I check for loose bearings in the rear? Wouldn't think so with 19k miles but I guess its possible. No noises or anything that I've heard...

I got some "500 mph tape" that they use as temp patches on planes. It is aluminum and thicker then the "foil tape". Gonna try that tomorrow and see if I can get them tight and go from there I guess. This has been THE MOST frustrating thing with this car...:mad::mad::mad:


Stupid question maybe but if a bad hub was the problem,would the road force balance job know the difference?

Yes,it is possible for wheel bearing to be bad at only 19K miles.

[gbrtng]

How do I check for loose bearings in the rear? Wouldn't think so with 19k miles but I guess its possible. No noises or anything that I've heard...

Tire off the ground, E-brake off, grab tire at 12 and 6 pull-push. There should be no play, but I have run with as much as 1/8" play with no vibration. And all C4 bearings are the same - ZR-1 and base car. You might have a couple of bad half-shaft u-joints ...

[GOLDCYLON]

Tire off the ground, E-brake off, grab tire at 12 and 6 pull-push. There should be no play, but I have run with as much as 1/8" play with no vibration. And all C4 bearings are the same - ZR-1 and base car. You might have a couple of bad half-shaft u-joints ...

This will work but the best way is to pull the tire and grab on the rotor/hub at 12 and 6 and the 3 and 9. There should be little to no play while trying to move it left to right

[Franke]

Do you have someone nearby that could lend you their wheels for a run down the road to eliminate the possibility of tire/wheels.

[GOLDCYLON]

Do you have someone nearby that could lend you their wheels for a run down the road to eliminate the possibility of tire/wheels.

Great idea

[Dynomite]

Do you have someone nearby that could lend you their wheels for a run down the road to eliminate the possibility of tire/wheels.

That will work like Daryll said :thumbsup:

[Racinfan83]

Wish I did...:cry:

[Vette Guy]

I chased down a vibration for a long time.... Rims, tires, bearings, u-joints.... Switching out the driveshaft and yoke made all the difference. I intend to have my original drive shaft and yoke balanced, and anticipate they will be able to tell me how much off it was. My vibration was bad around 68ish, above or below, it wasn't too bad... Eliminate one variable at a time if you can. Good luck.

Mark

[Racinfan83]

I chased down a vibration for a long time.... Rims, tires, bearings, u-joints.... Switching out the driveshaft and yoke made all the difference. I intend to have my original drive shaft and yoke balanced, and anticipate they will be able to tell me how much off it was. My vibration was bad around 68ish, above or below, it wasn't too bad... Eliminate one variable at a time if you can. Good luck.

Mark

Yeah this vibration is at any speed above like 50. Below 50 you just can't tell it. It is not a harmonic vibration like I have had with bad u-joints in other vehicles. Checked the half shaft u-joints they are tight. Will check hub bearings today. Rotors aren't warped - stops smooth as silk when braking. (Had my share of those on other vehicles too) I'm not blessed with a plethora of ZR-1 friends here in this area that I could go swap wheels with unfortunately. Wish I was closer to the Chicago gang but that is over 5 hours away....

[WVZR-1]

Knowing what you've been through and have done chasing the issue I'd think your only reasonable diagnostic tool would be to do a ride along with someone or drive along and if you find a car that "suites you" (not meant in sarcasm) at speed, you then take those tires and wheels to your car and see if your car still has the same issues or not. There is no other economical or feasible way to accomplish it.

It would easily be worth a couple hundred mile drive to evaluate another car. You mention before hand the speeds that are your concern or where it's most notable. Have that person pass on to you that his car passes the test he feels and you then do the drive.

If his to yours passes the test you move yours to his car and see if the same scenario plays out on his car. Two tire swaps and the diagnostics are done.

I would think I'd be interested in doing this with someone that has recent tires and maybe stock wheels or if the wheels are aftermarket that their "hub-centric" because there's a few less hassles although as it's been mentioned there's nothing wrong with "lug-centric" and regardless of the center-bore Corvettes are actually "lug-centric" although it's done on wheels that are very close to "hub-centric"!

A good day of driving, lunch or whatever and it's done/over - no more diagnostics.

If you only wanted to do the swap one way from a car to yours you wouldn't need a ZR-1, just a C4 with newer tires, stock wheels and "no issues"!

[batchman]

With no other candidates (c4, c5, 80s/90s camaro/firebird/bmw/others?) to swap a pair of tires (might as well do one end at a time) you could just put your donut spare on one corner at a time. Pain in the butt but will narrow down to which tire or is it the car. So if you move the spare to all four corners and still have the vibe, it's the car.

I get *maybe* 200 miles out of a hub. *Any* hub. It's not the mileage, it's the history.
Forget hub centric, if your lugs are correct and torqued correctly they hold the wheel through much more abuse (see 200 miles on a hub if I'm lucky) and my competition wheels are lug centric only.

Have you had an alignment, did the tech notice one corner needing or having a lot of adjustment range taken up?

You could have more than one bent wheel, in either or both sets too!

HTH,
- Jeff

[A26B]

I chased down a vibration for a long time.... Rims, tires, bearings, u-joints.... Switching out the driveshaft and yoke made all the difference. I intend to have my original drive shaft and yoke balanced, and anticipate they will be able to tell me how much off it was. My vibration was bad around 68ish, above or below, it wasn't too bad... Eliminate one variable at a time if you can. Good luck.

Mark
I agree with this possibility..... driveshaft may have been removed and re-installed out of phase, meaning it was not installed in the same position on the differential yoke just as it was removed. This has happened before.

May also be a worn front yoke or worn tail bearing/bushing allowing the yoke to oscillate. Over-tightened front C-beam bolts can cause the bearing/bushing to incur accelerated wear.

Suggest:
1. Check with the previous owner to see if the driveshaft has been removed, or
2. Use 2 post lift, in neutral, turn the tires & check driveshaft run-out near both front & rear u-joints and in the middle.
3. check for excessive movement of front yoke. If noted, will require removal to determine if yoke, bearing/bushing or both are a fault. If the yoke is to be replaced, contact Bill Boudreau at www.ZFDoc.com (http://www.ZFDoc.com). The correct Spicer yoke can be difficult to find. Bill can tell you the difference from a commonly available yoke which is not quite right.

From Bill (ZFDoc) Boudreau;

Just to warn you up front, finding a suitable slip yolk replacement will be extremely difficult since SPICER discontinued production of the 2-3-13131X slip yolk assembly. There is no shortage of replacement slip yolk assemblies that claim to be exact replacement units of the original SPICER unit, but what they don’t tell you is that in new form, these knock-offs have the same excessive spline play equivalent to an original 2-3-13131X slip yolk with 100K miles spline stretch on it.


None of the above checks will be difficult or expensive and may help to eliminate a distinct possibility. Looks like you have been through the wheel/tire possibility pretty thoroughly.

Good luck.

[Racinfan83]

Well - haven't driven it yet - but I took wheels off again and applied a strip of the airplane aluminum tape around the inside of the wheel bores. Stuff was only a couple thousandths off if that when I measured the inside after tape vs the hub. Hopefully...
Pulled on the rears at 12/6 and 3/9. There is maybe 1/16" movement in both at the outer edge. Good, bad, can be tightened with the nut???
Spun the fronts and tried to look across the top of the tire aligning with a washer edge on the inner fender. They look to be pretty round - just the slightest hint of difference. Once again thats the eyeball method which is what I have.. They do not appear to have any sideways runout at all.

On the driveshaft deal - would that cause a steady vibration or a harmonic one? This is steady. Does it even if I put in in neutral and let it roll. I understand the shaft is still turning but the pressure is off it. I and the mechanic checked it when it was on the lift and could not find anything even remotely loose. Can't find the PO - the guy I got it from got it at auction and didn't do anything to it other then let it sit in his garage.

Alignment is a possibility - haven't gotten with the local guy here to get it on the rack yet. Measured with a tape and boards like we do on the circle track car and appears to be close - although I know that is the "redneck method"..
Will drive it tomorrow to a show - see what it does then. I have to get ready for dirt racin tonite...

If this stuff don't work maybe I just need to suck it up and make a 5 hr trip up to see the FBI gang and swap wheels with one of them...
Thanks all and will let you know..

[WVZR-1]

I agree with this possibility..... driveshaft may have been removed and re-installed out of phase, meaning it was not installed in the same position on the differential yoke just as it was removed. This has happened before.

May also be a worn front yoke or worn tail bearing/bushing allowing the yoke to oscillate. Over-tightened front C-beam bolts can cause the bearing/bushing to incur accelerated wear.

Suggest:
1. Check with the previous owner to see if the driveshaft has been removed, or
2. Use 2 post lift, in neutral, turn the tires & check driveshaft run-out near both front & rear u-joints and in the middle.
3. check for excessive movement of front yoke. If noted, will require removal to determine if yoke, bearing/bushing or both are a fault. If the yoke is to be replaced, contact Bill Boudreau at www.ZFDoc.com (http://www.ZFDoc.com). The correct Spicer yoke can be difficult to find. Bill can tell you the difference from a commonly available yoke which is not quite right.




None of the above checks will be difficult or expensive and may help to eliminate a distinct possibility. Looks like you have been through the wheel/tire possibility pretty thoroughly.

Good luck.

That's way more effort than doing a drive and swap wheels and tires. If the swap of wheels and tires makes it go away all is done!

I thought I was the first to mention the "service slip-yokes" supplied by most aren't any better than a 100k used one. I've a slip-yoke that's been used many times for correct fixes that only requires the use of a 1330/1310 conversion joint and the removal of 30mm from the end. It's got the correct major/minor spline dimensions. Still pretty readily available.

[A26B]

........I thought I was the first to mention the "service slip-yokes" supplied by most aren't any better than a 100k used one. I've a slip-yoke that's been used many times for correct fixes that only requires the use of a 1330/1310 conversion joint and the removal of 30mm from the end. It's got the correct major/minor spline dimensions. Still pretty readily available.

You may have been the first. I just ran across this statement from Bill and posted it as a reference to yokes. You are always an outstanding reference source!

[chriskinzel]

On cheap option is to get a friend to drive behind, to the left and right side while you drive at the bad speed. Have him (or her) look at your wheels. Look for bent rims, or tire bouncing. Anything out of the normal. This is basically free and maybe you might find something. Good luck.

Chris

[tonywy]

I had a similar issue with my 90. Went nuts trying to figure it out. Changed everything you could think of, including two sets of wheels, two sets of tires ,a steering rack. Turns out it was a right front shock that would not compress. It would expand but would only compress to its nominal ride height. Low mile car, so it probably stuck in that position. Two new front shocks on, problem solved.

[WVZR-1]

I had a similar issue with my 90. Went nuts trying to figure it out. Changed everything you could think of, including two sets of wheels, two sets of tires ,a steering rack. Turns out it was a right front shock that would not compress. It would expand but would only compress to its nominal ride height. Low mile car, so it probably stuck in that position. Two new front shocks on, problem solved.

On cheap option is to get a friend to drive behind, to the left and right side while you drive at the bad speed. Have him (or her) look at your wheels. Look for bent rims, or tire bouncing. Anything out of the normal. This is basically free and maybe you might find something. Good luck.

Chris

The observation while driving mentioned by Chris could likely be used to determine if the problem is similar to that noted by "tonywy" and suspension related BUT in your earlier thread and in maybe an email conversation I mention an "on car" spin balance attempt and that I believe would still be the "tell all" if it's related to tire/wheel.

I like the observation while driving and I often see cars on the highway that I can't image how they tolerate it inside the car while watching wheel/tire reaction to the pavement.

I believe you need to do the observations and let someone else do the driving. You just pick the speeds, I'd think 70 MPH should show all. Good pavement a necessity.

[Racinfan83]

Yeah that I think I will do if this doesn't fix it. Plenty of freeways around here I could do that on.
I was going on an hour roadtrip today to a show - but there is a giant green/orange/red blob on the weather radar moving across the state. SO it will sit in the garage til tomorrow. :cry:

[batchman]

Pulled on the rears at 12/6 and 3/9. There is maybe 1/16" movement in both at the outer edge. Good, bad, can be tightened with the nut???

That much movement indicates the hubs should be changed. It is possible that re-torquing the axle nut (remove wheel, remove cotter pin and castle nut, torque to 168 ft/lbs) but the play will come back.

I have not found hub play to lead to a vibe - but it does lead to failure. A new record for me this weekend, about 12 and 1/2 miles. 3rd run in my national event.

Sigh,
- Jeff