Community Forums:

If you've got a whine it is probably either in the differential or the
tranny - that's where the gears are. Whines come from gears first,
maybe bearings but more likely gears. Check the lube in your differential
and tranny, and note if there are metal flakes. If so that is where your
problem lies.

Yokes: Look at your rear driveshaft and note how it has one yoke at each
end and they are exactly aligned. The front shaft has a slipjoint in it
but also has two yokes, one at each end. They must be aligned the same
way (relative to each other) as the yokes on the rear shaft. If not, you
will get pulsation or thumping because of the uncanceled change in rotational velocity when the u-joints work against each other rather than together.
If they are not aligned correctly you gotta drop the rear shaft, pull
the slip joint apart, turn it until the yokes line up and stab it back
in.
--
George Downs, The "original" Walrus3, Bartlesville, Oklahoma