Grab the diff carrier and look on the sides of the bearing risers, see those stupid little ears that come off of the bearing risers that appear to have been ground to shape?

Those little nubs have almost zero clearance inside the rear axle housing, look in there and you will see what I mean.

Cover the diff really well with bags/cloth and grind a little off the outside face of those nubs. I have had diff carriers that wouldn't fit into any of the axle housings I have without a little clearancing on those damn things.

Isaac

 

This is an mpv diff, but the same setup, I circled the little nubs, those are what you are fighting.




Isaac

 

I screwed around with it again last weekend for hours and hours...I think you are correct, those stoopid "nubs" are hitting that "shelf" inside the cavity and will not allow it to mate. When I initially lower the pinion housing into the axle cavity, those nubs barely clear the mating surface orifice unless lowered very squarely and some jostling around...Why would they not then clear that damn "shelf" in there, too? What the hell are they(the nubs) for, anyway?

 

Thank you flight_of_pain! I done did ground the sheet of them there "nubs" and it finally went back together! Now...Which way do the seals go? A facing towards the wheel or B facing toward the wheel?

 

The cupped side goes inward.


Isaac

 

Well today I finally got the oil seals and axles installed(of course after first putting them in the wrong sides and couldn't route the brake lines, then tried hammering them back out with no luck until I took the nuts back off the backing plates...dope), got rotors and wheels on it, and pulled it outside under the car...It did not act at all like when I initially removed this rear, or the rear out of the car it's goin into. What I mean is; with just wheels on the rear, and pulling/pushing it around by the pinion housing...If I needed to negotiate a turn or change of direction, I could just rotate from standing in the center. One wheel would move in the opposite direction from the other, and it would "turn". With this diff I rebuilt and installed, it was posi ALL the time pushing it around, I couldn't rotate the assembly and have the wheels turn in opposite direction. I forget to buy 90 wt gear oil for it, and found a couple old bottles laying around. I dumped in everthing I had, don't know of the level, the pinion was pointed at the ground when I filled. One was 75/90 wt(a full bottle) and the other was a little under half a bottle of Lucas heavy duty gear oil that was something/155 wt. I of course didn't have the LSD additive for it yet either.
Do I have reason for concern? Did I build the stack too tight? Does it just need broken in? Does it just need the LSD additive? A result of the heavier gear oil and/or improper level? What are your experienced thoughts, anyone?

 

Well, finally got the DRIVE the car with this rear in it. Posi works...Checked it out in the neighbors yard, then on the road NO chatter or noises negotiating tight parking turns or anything. BUT while driving I hear a constant noise from the rear that was never there before. The only way I can describe it is that it sounds like a HUGE rotating metal disk all the time. It changes in pitch or frequency slightly when you accel or let off and when you go over big bumps at speed. The FIRST test drive, I got about 30-40 feet down the road before this noise made me abort and turn around(I remembered I never topped off the fluid level or added the lsd additive and was convinced this was the cause of the noise). It wasn't. Otherwise it seems fine, do I have reason for concern?

 

Incorrect gear lash will typically be different sounding whether you are putting power into the diff, or coasting. Wheel bearings, or pinion shaft bearing are more of a growl.

Isaac

 

Nothing sounds bad or wrong...Just is a loud sound of a large rotating metal mass ~slightly~ dragging on something. Almost like a brake pad close to the rotor, but lounder and different. Def. not the driveshaft on heat sheild or anything like that. I was also convinced once I put all the insulation and interior in, I wouldn't hear it, but it's just as loud. Sounds like this even at the highest height setting for rear, and lowest. I did not replace carrier bearing or pinion bearings, they were great. Wheel bearings are brand new. Backlash was set to ~.005", not .004" by backlash dude, he wouldn't set it any tighter, he say it'd be quiet and smooth.

 

isnt that out of factory tolerance for lash? in Steve84GS's rebuild thread, he states that the factory lash setting should be between .0035-.0043"

 

Yes, that's out of factory spec, but "backlash dude" wouldn't set it any tighter...So far EVERYONE who has ridden in the car inquires about the sound from the rear. There doesn't feel like excessive driveline slack or anything negative, but I can make the sound go away if I match the driveshaft's rpm with the real wheels' rotation whilst coasting downhill...