97 ZJ select trac 4.0 auto. 200k all stock.

Over a few weeks this whining noise came up in neutral and drive. Sounds almost like your turning a piece of metal on a lathe scribing it with small tool.
It speeds up slows down with vehicle speed. haven't tried it in 4wd yet.
Rear diff seals, axle bearings and axle have been replaced so would think that area is ruled out.
Thought it may be the front hub bearings which were pretty loose.They are being replaced right now.

If this whine continues what could it be ?

I have seen some posts regarding the Transfer case bearings or Pinion bearing on diff. -I will change the frnt Diff gear oil. as it may have never been changed so far.
Can transfer case oil be drained/ refilled?

Vehicle is used for commuting to work and 2-3 hrs drives to the mountains -no real off-road use.
Thanks

 

i had a similar noise and it was from part of thew caliper being messed up and grinding on the rotor.

 

Thanks for both replies to my posts,
Right now the vehicle is in the shop disc brakes are off due to the hub bearing/axle replacement so I'll ck it out.
Hopefully it is not a transfer case/ diff bearing issue, Kinda tired of replacing parts on this for now.

 

I have searched thruout the forum and seen alot of posts re;whining noise, some point to the Diff and others the transfer case,
Is there a definite test for either to find out exact location/cause ?

 

Jus tand update for all:
the Whining noise was the front hub bearings -Replaced both sides and all is good
Really hard to tell location of noise when driving. Seemed like unless you or someone sits on the hood while driving and hangs their ear down , You'd never guess where it's coming from !