'01 Pathfinder - vibration from rear in reverse

[Towncivilian]

Whenever I'm in reverse, there's a strong vibration coming from the rear of the vehicle every few seconds. Transmission fluid/filter changed at 120,340 miles with Genuine Nissan ATF & Beck/Arnley filter/gasket kit, but the fluid smells a little burnt (still red, though) and somewhat overfull so I'm thinking of doing a drain and refill using Valvoline Maxlife ATF to clear that up. Rear differential fluid has probably never been changed; will change that as soon as I get a new drain plug (both plugs are stuck, several applications of PB Blaster, a hammer, and a 25" breaker bar should take care of that though), using Valvoline 80W-90 gear oil. Something I'm missing, or is this just normal behavior? I believe this also occurred before the fluid change too. Vehicle currently has 121,092 miles.

 

[unDummy]

Bad drive train mount or u-joint. If there is a slip joint, might want to repack it with grease. If you have u-joints with zerk fittings, use your grease gun.

 

[Billbert]

Originally Posted By: unDummy
Bad drive train mount or u-joint. If there is a slip joint, might want to repack it with grease. If you have u-joints with zerk fittings, use your grease gun.



+1

 

[Towncivilian]

I'll have to check if I can grease the joints. The factory service manual says nothing about greasing those, just the propeller shaft.

I noticed that the vibration isn't always present, but usually when stopped in any gear (not just reverse) the car will vibrate somewhat from the rear. No issue in park or neutral.

I realize I may have posted in the wrong section; my apologies!