Rear End Wobble?

[RRoller123]

Thoughts on this wobble of both rear wheels? Axle? Out of round tires? Bearing issue? ??

https://i.imgur.com/DsZayo8.mp4

(cant get the video to upload?)

[redcars]

Wobbly rear wheels is normally bent rear wheels, switch the front and rear wheels and see if the wobble follows the wheels. If so then the wheels are bent. If the wobble stays with the rear end then the axles are bent.

[tima01864]

How do the axles get bent? What would cause that must be extreme impact? Could it be the bearings are not concentric when pressed/installed?

[RRoller123]

We could see the wobble on the hub, although obviously less due to the much smaller diameter compared to the tire or wheel. Probably close to 1/8" out at the tire perimeter.

[DieselSpider]

Hard to say with the camera jumping all around. Set a pointer at the edge of the rim and rotate the wheel by hand to measure any deflection there and then at the hub. At the speed the wheels were turning a defective tire could telegraph its out of balance to the axle and cause the whole assembly to wobble.

Could be an tire with a flat spot from sitting parked too long in one spot, partially herniated tire, bent rim or bent axle shaft or something as simple as the rim was not bolted centered on the hub or the mating surface between the rim and the hub needing some corrosion or other debris cleaned off.

When you check for lateral and vertical play in the bearings does it all seem solid or otherwise?

[tima01864]

Have to take a closer look, The rear end comes from a 70 124 installed by owner previous to PO. Changes from 83 to 70 may not really allow that.When all this vibration is solved and fixed I will have a good car. I did clean the rims of rust where they seat on the spacer and also cleaned rust on the spacer and painted. New rotors

[RRoller123]

No obvious bearing slop at all.

[tima01864]

Danny at Fun Imports thinks it is the tires wheels from looking at the video, Will figure that out!

[tima01864]

Put an indicator on the rotor, was true within .010". Installed a rim tourque 65 lbs, no tire, was running out 0.050". Installed another rim. same thing.

[DieselSpider]

If you swap the front rotor to the back are the results the same?

Could be uneven rust cleanup on the spacers too. Some use way too aggressive a method using a grinder instead of a wire brush or medium grit sand paper.

[tima01864]

I cleaned the spacers with a razor blade and a flat file. These are used rims too, EXIP 15". It surprised me that the lugs on the rear are all that centers the wheel. Tried rotating 90 deg, then 90 more. Out around 0.050 up and down. First indicated the rotor and face of spacer, was in around 0.010. Really cold up here.

[DieselSpider]

I cleaned the spacers with a razor blade and a flat file. These are used rims too, EXIP 15". It surprised me that the lugs on the rear are all that centers the wheel. Tried rotating 90 deg, then 90 more. Out around 0.050 up and down. First indicated the rotor and face of spacer, was in around 0.010. Really cold up here.

Well that and the locator pins. The critical alignment though is on the fronts.

[tima01864]

I brought the rims to Firestone, Tech said they were fine when he balanced the rims. (Rule out bad rims) Aftermarket rims, the locaters don't come into play. Maybe the nature of the beast, The fronts should locate on the hubs, next go around will look at those.

[DieselSpider]

Yes the centers on the front hubs do make it easier however they don't need a spacer like the rear axle does. I believe they made one short axle and then adjusted its track with spacers so it would work with multiple cars. I would have preferred that the spacers had centers on them and have thought it would be a great upgrade to get new spacers with locating centers on them.

[tima01864]

Curios, I will look next time at the car. I remember all wheels had spacers? I been thinking on a way to center the rears, but none that would work. I could turn an aluminum, there is only an eighth between the hub and rotor to locate on. Too bad, Have to rely on the tapers on the lugs and getting the tourque to set them on center. I will fit the rims with tires, try to get them centered, Never given this much thought before. Good luck I say