More info on the issue(s):

I hear a "growling" sound that increases in pitch when I'm accelerating and decreases in pitch when I remove my foot from the accelerator (there's a big "gap" or "loose" feeling between the two though I'm not quite sure how to word it).

I'm convinced the rebuilt transfer case is good and the entire suburban feels tighter from having replaced the bearings (rear wheel bearing, rear carrier bearings, both drive shaft universal joints, both front wheel bearing assemblings), but once I'd installed the transfer case and put it into H4, I heard a big clunk and then received the message to Service4WD.

I removed the front driveshaft thinking that might shed some light on the situation, but it didn't do much. The noise is clearly coming from the front end center and it sounds like the differential.

I emailed the autoshop instructors at the school I was teaching at and at the school where my boys attend asking for advise. Both seemed to point to the pinion bearing on the front end differential (I can't believe I'd really ignored the front end differential, but I had ... I just don't do a lot of this kind of work, but I do enjoy the challenge).

My Haynes manual is very unclear with two sections that look very similar, but are very different. For example, 24 reads: "Right axleshaft, tube, bearing and shift fork (4WD and AWD models) - removal, component replacement and installation". Then, 25 reads "Axleshaft oil seals and bearings (front, 4WD models) - replacement" and 26 "Front differential carrier - removal and installation".

Since I've replaced the carrier bearings in the rear, the carrier bearings in the front seem to be likely culprets though I'm more tempted to believe the advise of the autoshop instructors (that the pinion bearings are to blame). Still, I can find very little on R&R on the pinion (or whether it would be a better decision to replace the entire front differential).

Has anyone done this work? I don't believe it's rocket science and I know there's a lot I don't know. It seems much of what I don't know is the correct vocabulary and references, but I'm working on it.

All advise is appreciated, but comments like "buy a Toyota" aren't productive. Btw, we have to Lexus' and they've had their share of problems, too. I'd also take it to a shop, but each time I've gone, it's cost a thousand $$$ and it's just not in the budget right now.

Thanks,
Bill

 

Rebuilding a diff is rocket science and if done incorrectly, will lead to problems.

 

i wouldnt call it rocket science but you definately need patience and have to pay attention, did you say you already did your rearend?? its basically the same you just have to remove the whole front diff and split the case instead of pull the cover