odd noises...broken 4wd

[steveroche]

So I have been holding off on posting this up here because I wanted to figure this out on my own but I can't find something I need so I thought I would post up a quick question to see if you guys could steer me in the right direction. So my 4wd isn't working. I believe I have narrowed it down to the 4wd disco. Both hubs are replaced, cv shafts are both replaced, 4wd actuator works perfectly, transfer case motors work, transfer case works. What I am hearing is a whirring sort of bad bearing noise coming from the front end. I heard an odd clunk in the front end when climbing a small slippery hill, then the front tires stopped getting power but the front drive shaft was getting power. There is a constant bearing grind noise that does not go away until i fully stop the vehicle. I have to get it on a lift at our shop and see if i can pinpoint the sound while looking under it. For now my question is, what are the most common things to break in a 4wd disco? If it comes down to it I am just going to order the parts that frequently are known to break, take mine apart and replace those parts and hope nothing else is broken in it...I know my cv shaft seal is fine, I inspected it yesterday. Thanks for any help guys...

[v7guy]

Kinda reminds me of the disconnect giving up parts. There's a ton of threads showing the parts that frequently die. It's getting pretty common for guys to put in the AWD sleeve. There are typically problems engaging 4WD with a broken disconnect though.
Only other thing I can think of is maybe the diff itself. But that's pretty uncommon.

[DirtyBacon04]

sounds like a front diff to me. I'd say crack it open and take a peek. Be prepared for some grit, though.

[JCrayton99]

I agree. Easiest thing to do is drain the diff fluid when you get it on the lift and see if there are bad things in it. Then go from there.

[steveroche]

Sounds good, tomorrow I'll do so at the shop and let you guys know what happens...

[steveroche]

broken driver side axle seal, muddy diff fluid, fail...ordering the new seals for both sides, as well as bearings, fork, and spring for disconnect and i'll rebuild that as well next week. Hope this fixes it all so I can get her back off road...

[steveroche]

While i'm at it I should probably also replace the upper strut bushing that fell out....

[Trail X]

A bad driver side diff seal wouldn't create torque loss to the front tires alone. Something else has to have failed.

Check the tripod on the pass side for movement when you force it up and down (don't be afraid to lean into it). If there is more than 1/16" of movement you will certainly need to rebuild the disco.