There is a slight pulsating vibration at 50-60 mph. The differential was just swapped out with a lower mileage one.

U-joints?

btw, found a RIDICULOUSLY cheap mechanic in the Tampa area for Jags.

 

Baby just wants to go 80.

 

The obvious possibility is that you lost a tire-weight and a tire is now imbalanced.

I think if you need an alignment it is possible to cause that too, but not totally sure about that.

 

get road force balancing ...pay the money for it and you won't be sorry...see this link

https://www.jaguarforums.com/forum/x...-worked-68347/

 

What exactly do you mean? And did it appear immediately after the differential swap?

 

Yes, I did appear after the differential swap. My tires are in bad need of repair, but its suspect that it came after the diff swap.

After going over 50mph... there is a vibration that is consistent and pulsating depending on the increase in speed.

 

Maybe you could try repositioning the drive shaft.

Usually when dropping the shaft it is marked to reinstall in the same position. That is impossible when the diff is replaced.

Did the whole shaft come out? Was the centre support bearing disturbed?

If you account for the possible 4 positions at the front and 3 positions at the rear, that is 12 possible positions to try.

But, in this case, you will only need to account for the possibilities at the driveshaft to differential companion flange.

 

Tires were the culprit....

 

Did the tires have flat spots ,or did you balanced the wheel?