I am finally getting down to tracing the noise I have been hearing form the new 81 240's rear.
I notice it most a low speed <20 mph and it feels like a rumble that is loudest as you are backed off the throttle and then back on it again. It seems to disappear when under constant load but it also may be blended with the rest of the mech clatter of the car.
I looked at the center carrier bearing and d/shaft ujoint and stuck a screwdriver into them and tried to see if there was any play in them and did not get any appreciable looseness.
I assume I will probably have to remove them to really check. Is this correct?
The driveshaft has no excessive rotary play and the flex discs look ok.
I loosened up the e brakes to eliminate any drag. The rt side adjuster is broken but turned in to the minimum and it rubs a little but that is not the sound.
There is a noticeable clunk at the diff when the clutch is released between shifts so I have drained, flushed and refilled the diff and did not see any obvious metal particles and the fluid while brown was still somewhat clear. Sound still remains.
Axle boots are intact but I have not confirmed that the shafts are ok though I also think they are not the noise.
I will be checking the rear wheel bearings next and hope it is not them as the fix looks involved.
Any help will be appreciated.

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1981 240D 143k 4 spd manual -SOLD

2004 VW Jetta TDI 5 speed 300k -still driven daily