I get a grinding noise when I tap or let off the skinny pedal at anyspeed over 30..it only lasts for about half a second..
sounds like its coming from under me
To try and fix this I have replaced oil/filter,tranny oil/filter,front/rear diff fluids, put front/rear tom woods driveshafts in, replaced wheel seals and bearings in the rear...still there..any ideas?

this is a 95 grand cherokee with 8.8 in rear/hp30 up front, claytons

Sounds like a bad bearing in either the tranny or Tcase, or possibly a missing pad on the shift fork in the tcase. WIthout tearing either/both apart, you might not be able to tell which is bad, but you coudl try to see if it is one of the output bearings by checking for an improper amount of end play in the shafts....

sounds like the fan is hitting the shroud. Check your motor mount and tcase mount.

Not much info to go on:
but is this tranny a Manual?? If so look at the throw-out bearing.

Auto tranny? If it's the front (input) bearing the seal will soon start to leak. The rear bearing like previously mentioned you should be able to view the excess play. But these bearings are in oil and you shouldn't hear "grinding", maybe a "howl" or "grumble". (for the lack of a better discription)

Most of these problems will "find you" sooner or later ..... so IMHO not worth dropping & disassembling a tranny before you're positive of the location of the "grinding".

I would have guess a U-joint in the drivelines first but you said you replaced those. Right?

good luck

sounds like the fan is hitting the shroud. Check your motor mount and tcase mount.

I've had this had happen to me before...check this next

i had some grinding, was my t-case bearing went and put my gears out of alignment. best bet is to check for metal shavings in the fluids. unless your sure its origin. when i first got my jeep the t-case grinding masked the bearing in the rear diff yoke. anyhow my money is on the t-case.

I have the same problem, I suspect it's the tranny or t-case.