Transmission / Overdrive: flightomatic transmission

[RayS]

is there anything in a 1960 flightomatic transmission that would cause the car to shake at 60+ mph ?

[StudeRich]

Probably not the Transmission, more like a "U" Joint, Driveshaft (bent, lost a weight, out of Balance), Rear Wheel Bearing, loose rear Hub & Drum.

Try to determine Where the it's coming from front/rear etc. maybe on a 2 post hoist or rear wheels jacked up etc.

[r1lark]

In addition to StudeRich's list, look really close at each tire & wheel, since a big knot from a broken belt or just a bad tire or a bent (or cracked) could make the car shake. Probably best to jack up each end and check each tire by rolling it and watching/feeling it.

[RayS]

Thanks StudeRich& Paul, I have replaced the u joints and balanced the driveshaft. the tires and rims are new. the tapered axle hubs and axle bearings are new along with new rear brake drums. all of that hasn't helped. I don't know what else to check. there isn't any issue with the steering or front suspension.
thanks for your response, any other ideas would be welcomed.
Ray

[64LarkLover]

Ray,
The only thing I could add is I had a 65 Studebaker Commander back in the late 1980's which began to shake at then highway speeds-55-60mph. The front king pins were worn and was the cause of the vibration-going from 30 plus years ago memories I think replacing the sleeves and bushing fixed this. Hope this is of help.
Rick

[StudeRich]

I think knowing THAT, all I can say is be careful, because NEW nowadays is not all that !
A "U" Joint could have been improperly installed, little things like that can bit you.

We had a Member here recently, that his problem and story sounded like it was exactly the same, he took the driveshaft back and had it re-balanced and found a mistake.

[RayS]

Thanks, the drive shaft was balanced after the "U" joints were installed.

[StudeRich]

You DO know that you cannot fully assemble the bearing Cups of a rear U Joint into the Differential on the Bench right?

[Jeffry Cassel]

It is both amusing and disturbing how so many in this forum assume competence in parts and serfice providers. I had a somewhat similiar situation decades back and discovered the problem when a friend followed me and said "You do know you have a bent rim, don't you?" It takes very little wear in a U-joint to make a vibration. Ditto bearings and bent axles. Fixing things that aren't broken seldom solves the problem, Make a disgnosis and then address the problem. (Rich: I do put the cups on and wrap a strip of electical tape around them to keep them from falling off and losing one of those very lose-able little needle bearings.)

[enjenjo]

I recently had a car with a similar problem. It would shake from 57 MPH to 61 MPH. My repair shop diagnosed it as a broken belt. When they were installing a new set of tires they found two bent wheels. So I bought two new wheels. That improved it but did not eliminate it. A couple months ago my Grand daughter noticed that when I pulled in the driveway the left front wheel moved back when I braked. There was a bad rubber bushing in the front lower control arm. I replaced that and the vibration is gone.

[StudeRich]

So Multiple issues caused your problem ! A Bad Tire with it's belt or belts broken, a Bent Wheel AND probably the major cause, a loose "A" Arm! ...Amazing.