Drivetrain rumbling noise

[Andrew Pawlisz <apawlisz@tufts.edu>]

Hi,

Recently, I have noticed a rumbling noise coming from the front
drivetrain (88 5ksq).  The noise seems to be coming from both sides.
Initially, I suspected the wheel bearings.  However, I was not entirely
convinced that it was them as I it is unlikely that both bearings would
give out simultaneously.  Moreover, I do not hear
"wwwwaaaaaawwwwaaaaaaawwaaaa"  when going straight or when cornering.
Futhermore, inspection of the wheels shows no play top-to-bottom or
side-to-side in the bearing what so ever.

What I do hear after driving for a few miles is a constant rumbling
noise thay does not change when cornering.  It only gets louder the
further/ longer I drive.

Last Saturday, I went under the car to look for the source of the noise.
I discovered that:
a. the left driveshaft has more play at the CV jonts than the right, and

b. the left driveshaft flange where it joins the inner CV joint has some
side-to-side play in and out of the gear box.

Question:

1. Could worn CV joints give me the rumbling noise? Eventhough, threre
seems to be no slack upon accelerantion/ deceleration?

2. Is the side-to-side play of the driveshaft flange from the gearbox
indicative of a shot differential bearing or worse, the whole final
drive/ gearbox?  ---and this is the real source of the rumbling noise?

Thanks

Andrew

Boston, MA
84 4ks
88 5ksq