[puttster]

I have a periodic vibration around 60 mph coming up through the seat. Probably the rear wheels but it might be the new tranny tail bushing, universal joint or driveshaft. To test those things I'd like to get the rear axle up on jackstands and run the engine in drive up to 60-70 mph. Theory is, if it still shakes the problem is in one of those things, not wheels.

Not sure what that test would say about the rear end or axles buit I would like to eliminate the tranny tail bushing,universal joint or driveshaft. Is this a good way to do it?

 

[FEandGoingBroke]

yes there is a good way.

Chock front wheels raise and support. Remove rear wheels adn place 3 lug nits snugly on rear drums.

Start, engage into gear, arrive at 60 or 70 mph. Feel or don't feel vibration.

STEP ON BRAKES to stop rear axle BEFORE putting in park....

Bad things:

1: Only ONE side is going to be turning.
2: There will be no load on the car so the test is kind of useless unless it's a drastic vibration....

 

[puttster]

how come take off the wheels?

 

[JD66Falcon]

If you take off the wheels and the vibe is not there I would say its a tire or possibly rim. A bent axle is always possible too. I have chased a vibe once that the only thing it could be was in the actual rear end as in the gears or pinion.