Swap front tires to back and spin it up again on jack stands and watch to see if the wobble goes away.  If it does not, you may have a wheel bearing issue.  Another issue may be the indexing of the u-joints when you reinstalled the drive shaft.  If a u-joint is not seated properly, or a needle missing, you will get an imbalance issue.    Joe-JDC

JDC

Does anyone have a road force balancer in your area? There was a post about this on the HAMB a while back. The tires can be indexed on the wheels to counter the wheel run out. A good shop that knows what they are doing can remedy it.

Durham Missouri

Good points. I'll get the wheels rotated and report back results. 

Not sure on a local shop with a 'road force' balancer. Someone on another board mentioned that as well. Will do some digging.

Thanks again for all the pointers.


Kent — Round Rock, TX
'56 F-100  | '56 Crown Vic  |  '57 Fairlaine 500  |  '57 Thunderbird

Check with a Nissan dealer, they've been using road force balancers for close to 20 years.

Back when I changed thousands of tires for Sears we always rotated the tires on the rims on a come back first before issuing new tires. It worked a lot of the times..

56 Vic, B'Ville 200 MPH Club Member, So Cal.

Eye-yi-yi … so much for wheels/tires. Upon checking for axle run out, a heck of a noise/vibration started. Does not do this in park. Only in reverse/drive. Double checked U-bolts. Can feel a small amount of slack in the yoke going into tail shaft of transmission. I have just replaced the bushing inside the tail shaft. Looks like it’s already leaking after putting a couple hundred miles on it. Doesn’t make sense that it would make that much noise and vibration at approx 15 mph in the video. Sounds/feels like it’s coming from inside the trans. What the heck?!?

Thoughts?

https://youtu.be/UMRg6J2dwVo


Kent — Round Rock, TX
'56 F-100  | '56 Crown Vic  |  '57 Fairlaine 500  |  '57 Thunderbird

WOW! Something is severely askew there. Since you mentioned driveshaft balance is an unknown I think I'd start there by taking it to a driveline shop and have them check it. I'm betting it is out of balance to the point that it beat up your new tailshaft bushing, hence the new leak. New u-joints would also be in order.

Agreed! Seems like the logical next step. Hopefully nothing internal damaged.

Kent — Round Rock, TX
'56 F-100  | '56 Crown Vic  |  '57 Fairlaine 500  |  '57 Thunderbird

When that was happening; did you happen to reach in the car and put it in neutral. If you did, did the clicking slow to a stop?
I know this would a lot of extra work but I would have removed the yoke from the drive shaft and slipped in the trans and tried it again.

56 Vic, B'Ville 200 MPH Club Member, So Cal.

I did put in neutral and it slowed down. I think the issue is the slack in the slip yoke and bushing. This was an issue before that was inadvertently fixed without realizing. Replaced the bushing due to the leak at the rear seal. Now that the car has been driven a couple hundred miles and developed play again, it's obvious the driveshaft needs to be balanced. Will also go ahead and buy a new slip yoke as well.

Once this is fixed, it's back to wheels/tires.

Kent — Round Rock, TX
'56 F-100  | '56 Crown Vic  |  '57 Fairlaine 500  |  '57 Thunderbird