Weird vibration and whirling/humming noise only under decel? HELP!

[cupajoe]

Let me know if swapping out the rear diff works out for you. Have you already tryed changing the fluid?

 

[MellowVR4]

I changed it about 8 months ago or something like that. It seems like it gets worse everyday, i try listening for it while im driving but it sounds like its in the rear but then sounds like the front aswell, /ubbthreads/images/graemlins/dunno.gif maybe im going crazy. I thought it was my driveshaft support bearings so i replaced them aswell as the u-joints. So next on my list was rear subframe bushings and diff. See how that goes.

 

[mooserage]

Yeah the entire drivetrain will resonate (right word?) the sound across all the parts making it really hard to pinpoint.
-shamus

 

^^^^ I'm guessing that's what happening with 1886. I hear this resonating humming/howling sound cruising around 55-65mph around 32-3350rpm. The sound is present when coasting, but nothing on acceleration/deceleration. With what I've been learning in my auto tech program I hypothesized that the pinion gear might not be seated right, either it sits too high or too low or too deep or too shallow on the ring gear (yes the sound is resonating from the rear of the car). Is this normal on the GVR4's with the 4ws still functioning?

 

[cupajoe]

Coming back from the dead. Lol. I'm not sure but mine went away when I changed my drivetrain fluids.