further bench work:
Took drive axles apart for grease change.
My D had only 17K miles on the meter and that grease had become as hard as drying clay.
ANYBODY not sure when this job was done on yours no mater how many miles on your speedo, 30 year old grease in a semi airtight compartment like that can get sufficient for lubricating.
Please schedule your change as well. It is an easy job, yet time consuming and messy. Or just have a shop do it for you.
Here is the picture:
This one didn't look too bad. In fact it was the only one which the grease was still in good shape.

The other three ends looked like this:

before cleaning

after

VIN 5992/Body 5697/Frame 6000/Grey/Manual/LEDs/HALOs/SPAX/DMOCO SS shifter/MOMO/Custom SS exhaust/K&N/SS: f.fascia mounts,brake+clutch lines+tank cover+heat shlds/Posi-quiet brake pds/Poly bushing: steering +f.sway bar +radius.