BlueBalls

Jeep:
2001 Sport Limited
228K
4.0L I6

Approx. 2 weeks ago I started to notice this problem and many things have been tested, checked, diagnosed.

I was coming home from a friends and noticed that each time I turned there was a weird popping, chattering, 10 speed bicycle-ish kinda shifting sound.
I thought NO problem will rip the front end down and verify that all is good. Prior to this allot had been replaced.
{Replaced}
motor mounts
axle u joints 2 yrs ago.
hubs 1-3 yrs ago.
suspension parts including springs, bump stops...uca & lca 2 yrs. ago. As was the diff mount bushing on d30.
steering parts TRE's , track bar, drag link, stabilizer shock, pitman arm, steering pump...etc.
shocks
brakes and all associated parts 2 years ago.
Did an examination and all passed with flying colors.
SO NONE of these parts were bad lol!

Figured the next thing to do was place the XJ on jack stands with the drive shafts removed and test.
At this point it was diagnosed as a bad Transfer Case and I tore it out. (Took the original case apart - bad chain, bearing etc..)
I contacted the local Pul A Part and sourced another NP231J with all associated parts as mine were junk.
This past Thursday installed the T-Case (with new trans mount) and finished with the rest of the stuff on Saturday.
Everything was reinstalled and double checked.

Went for a run around the block and all the original bad T-Case sounds were gone.

NEW Problem! (Junk yard T-Case)

I now have a grinding stone sound when I put the XJ in 4WD high.
I don't mean when I shift it into gear. I mean when I'm driving strait ahead at 10-15 mph it grinds just like someone at a grinding wheel.
Sunday tested the XJ with the front DS removed and the noise was gone in 2WD, 4WDh and 4WDL. While driving on ground.
Figured the front DS was problem[ found some rust and crap in bearing caps] .
Monday (today) took the front end all back apart and removed the Diff carrier and inspected the bearings. There definitely bad. Drivers side race and bearing are pitted, scored, flat spotted...etc.

My concern is, if the carrier bearings are scored on the drivers side of the carrier should I also check the pinion inboard/outboard bearings?
I can spin the pinion yoke and I don't hear any unusual noise.
My other concern is could it just be that the replacement NP231J (junk yard) is cr@p?
Which would be odd because the grinding was completely gone when the front DS was removed.
I suppose it is possible that the bearing in the T-Case could be bad on the 4WD output side.....although I get a small amount of grinding when in 2wd with front DS installed.
The other thought I have is with the Diff Carrier bearings damaged that might be what is causing the grinding any whoooo?

Thanks for reading and thanks for any help. Sorry about the long 1st post.
I've read a lot of stuff for several years from this site but really never needed to post b4. Usually got the answer just from reading other peoples post lol.

Wanted to amend this;
As of Tuesday 112321
Tore the pinion bearing, yoke, crush sleeve etc. out to inspect. There in excellent shape. Other than some very fine hair like scratch and a bit of tarnishing on the races they are fantastic.
That is great news by the way.
Also, rebuilt the original np231J transfer case with all new parts.
Ordered a master rebuild kit for the D30. should be here this week.

agreen

Unless you have experience with setting up gears, I'd just source another axle. The D30 front axle is pretty common. And you have a low pinion axle, so if you get one from a 99-, you can get a high pinion D30

BlueBalls

Yes, I've got the basics covered with the d30 rebuild.

Dave51

The way you describe the sequence of events the new (used) TC is the source of the noise.

I tend to be frugal (cheap) so if the pinion preload is OK I'd leave it and just fix the knowns (universals and carrier bearings). That said,

the rebuild procedure is not "let's rebuild half of it and hope for the best". If the carrier bearings are worn then some of that material hit the pinion bearings and they are undoubtedly worn. In for a penny, in for a pound, change 'em all out.

BlueBalls

Yea, I whole heartedly agree. I'm in all way up to my curlys at this point lol.
I'm uncertain about the junk yard t-case. It does lend itself to being the problem, which sucks because it's not exactly light weight. The time alone to get it out/in is no cake walk either.

BlueBalls

Have the necessary differential rebuild kit and fluid now. Will try to get this done this weekend. Just got the drive shaft Tuesday night. I'm hoping that is all I'm needing.

BlueBalls

Well my 1st attempt at doing the axle/diff was an absolute ^%#!@^$%#!$... lol!
Just kicked my Irish ****. But of course I'm not going to quit.
I've regrouped and ordered more supplies. Also, picked up some more tools.
The weather was like 30degrees Fahrenheit the other night and it was just cr@p.
Plus, I had nothing but problems with the Motive Gear stuff (just my experience and opinion) which caused more horrible headaches than it was worth.
The bearing closest to the yoke was completely wrong as was the race.
The bearing and races for the diff carrier were actually the part #'s for the rear D35...Ugh!

Today I ordered the Timken bearing master rebuild kit for the LPD30.
It listed the exact items necessary. It also includes a crush sleeve and proper pinion seal.
The Motive Gear provided a really poor fitting seal. NO crush sleeve and poor fitting components.

Dave51

What was the Part# for that kit? Maybe it was for the older D30.

RCXJ

I will think about this and get back with you

RCXJ

true

BlueBalls

Well got it back together. Have yet to test drive. Will update.