Front pinion bearing R&R

[Jeff Discos]

Piece of cake, right? DIY job?

Well, something in the front diff is slopping around a bit too much. I had someone sit in the car and put the car from R to D and back again a few times. There is a lot of slop in there. It looked like the pinion bearing from the play I could see. Silly me, I forgot to grab it and shake it around. I'll do that when it stops raining and I can get under there on dry ground.

Oh, and could it possibly be inner axle bearings? There are inner axle bearings, right? (inner axle = ring bearing? d'oh!) hehe...never taken an axle apart in any fashion, but I just may do that after diagnosing it properly.

Thanks again!

Sidenote: Oh...my girlfriend has finally admitted that she really likes my DI. It took her awhile, easy to understand with all the earlier maintenance the Disco was requiring, and therefore, $$$. She almost wants one herself now! This is great, coming from a very ******** Chevrolet background. (her dad owns numerous '57's, a nomad, trucks, etc.) He calls my car 'King George's Revenge'. Hah! Then again, I don't want her to get one...we want to buy a house soon.

 

[Sergei]

There are 4 bearings in diff.

Pinion bearings (2 different ones) will normally produce oscilating growl or just freaky growl / crunch when go bad. In same cases play will be enough to destroy oil seal. Vibrations via driveshaft.

Normal procedure to detect - shake bloody thing. However if everything is tight - it still may be broken, but appears just while moving.

Diff housing bearings (equal pair. I guess thats what you called inner axle bearings) will cause growl, crunchy sounds and side-to-side play inside differential.

Either one is not hard to change. Its not easy per say, as you got to mess with lots of crap and then be carefull about preloads, run-outs & etc - but its not something to be totally terrified of

Eventually it all boils down to having torque wrench, bench or hi-lift handy (so you can set up torque on flange nut without much ado), dial measuring thingy to sort out runouts and either very good eye or prussian blue permatex stuff to check out that contact between pinion and crown is even all the way. Rubber mallet is of huge help, unless you got press to push bearings off pinion and push them on (diff housing ones arent pressed)

Having air tools to get out those bloody nuts on 3rd membery and putting them back helps too

 

[Jeff Discos]

Thanks Sergei

The third member doesn't have to be pulled to replace the pinion bearing, does it? I'm not hearing the growling you spoke of, but there is some vibration that I've just begun to notice. To pull the 3rd, you have to pull the axle shafts, dontcha? ewww, don't really want to do that yet.

 

[Sergei]

Jeff - you have to literally disassemble whole thing to get inner (big one) bearing off pinion. Outer (small one) you may be able to take out by removing flange oil seal and having some tools...

To pull out whole thing eah - you got to slide axles off. I just done it so many times by now that i am doing this automatically

But if you notice vibration - i'd suggest first look at ujoints and how tight bolts on flange. Those buggers, if tightened unevenly may produce quite nasty vibration. Also it can be loosening flange nut. Its got to be tightened up to 127Nms (or something like that) and my truck moves forward when i am getting about 100Nm... Basically - try to see if there is play in front end.

Play can be from not quite tight flange bolts (4 of those) or loosened nut or u-joint.

If that fails -then you may need to renew bearings and reset preload on pinion..

Also can be something as simple as unbalanced tire or alignment wee bit off ..