Has the driveshaft been balanced or has the spot welded counterweight come off??

Lance,

I have not had them balanced.
When I first bought the car I found the shafts were out of phase, causing a vibration. Switched the out of phase shaft back where it should have been and it cured that portion of the vibration.
I will look to see if there is a spot weld holding a weight.
Is there supposed to be one on each shaft?

Rob

If you get a clunk going into forward and reverse, it usually means the idle is set too high.I'm sure you've replaced the u-joints.

That "clunk" could also be a loose axle shaft nut.

You have to make sure both drive shafts are lined up. They are marked and when laying on the floor the u-joints should all line up. Walt.

Try putting the car up on jack stands run it up to the vibration speed and see what is shaking. You can eliminate the tire/wheels by removing them and run it up again. I have seen brake drums that have caused a vibration. If you feel the vibration in the steering wheel, the problem is in the front. If you feel the vibration in the seat it is from the rear. Make sure you have the stands under the diff housing and not the body so the drive shaft is not hanging at a steep angle. Pay close attention to the tire and rim for runout. Good luck

If it seems to be at the rear, double check that the differential-shaft pinion nut is tight and there's no looseness at all in the shaft. I had a hard-to-find vibration in my '51, and found the pinion-shaft nut wasn't tightened down, so the shaft bearings were loose. That was the Hudson differential of course, but could happen with a Dana as well, I would think.

I put it up on stands and checked the two drive shaft sections.
Neither have any sort of balancing weight, or evidence of having one.
The shafts are in phase.
The "U" joints are not loose.
The pinion nut is tight.
The wheels are tight on the axle, so the axle nuts seem good.

I did discover I have 0.12 lateral run out on the left rear wheel though...must have hit something since we put the new tires on and checked everything...

So, I'm in the market for a rim...The spare is worse, which is why it is the spare...

Thanks for the help!

Rob

Standard rim Rob? If so I can help with that. 704 792 9110.

Did you actually check the axle nuts? Remove the split pins and check them to be real tight (120 lbs min.)

As Geoff and Lance have recommended, have the driveshaft balanced by a known good company and remove the cotter pins on both rear axles nuts and check the torque. Is the hertz level real fine or slow. Is the vibration in the seat, steering wheel ?. It could be the rear end as well. Make sure it has the proper hydramatic support bracket at the center carrier.

Lance,

Thank you.
I think have one located close to home, if not I'll give you a call!

Rob

Jeff and Doug,

No, I have not pulled the cotter pin and put a torque wrench on them, but I will!

Vibration is in the wheel and seat, but more in the seat. It feels like it is in the left rear area of the car.
I put the car on stands as Chris suggested and the left rear wheel is way out. I removed the wheel and tried with just the hub. Still some vibration and wobble (lateral). I haven't pulled the hub yet to try without it.

How quiet should it be when spinning?
There is some growling.
The vibration when driving is well, like a slightly bent wheel. At low speeds you don't notice, a higher speeds it becomes annoying.

What would/could be wrong in the rear end, bearings?

Thank you both.

Rob

Rob, I think the wheel should be replaced. You can go to classic wheel and buy new ones. Drill out the clips for the caps on the old wheels, weld them back on and you have a new set of wheels. These wheels are 5 on 4.5 x 6" . There is nothing like a new, true rim, so just an option. With your plans in towing long distances, I would recommend changing the wheels anyway. You will be glad you did !