Need R200 L/S diff rebuild... Who? Where?

[ZSaint]

I bought a 3.9 R200 limited slip differential on eBay a year ago. I looked at it after I bought it and it did not have any metal shavings or mismatched wear pattern. I installed it and it is a noisey diff. It has a howl and the clutches are worn out. You can turn one wheel by hand when the other in on the ground! I think it has about 5# of tension on it. I need to have it rebuilt this Winter. I live in the Salem/Portland area. Who is the best rebuilder? I know everyone says they rebuild these rear ends but few succeed. I do not want to get back a noisey ring and pinion. Hell, I can do that! :devious:

[jmortensen]

I bet your diff isn't worn out. I found out some interesting things about Nissan LSDs and advertised vs actual breakaway pressures: http://forums.hybridz.org/showthread.php?t=92629

As far as the howl goes I had mine rebuilt by a shop when I first got it about 8 years or so ago and they screwed it up 3 times before they got it right. What I'm saying here is there aren't too many shops that have dealt with the R series diffs before. Not like they're particularly hard to deal with, but they aren't the usual Ford 9" (which is really really easy).

After I tore into it the last time to shim up the LSD I looked at the bearings, and I think I know what causes the noise. I believe that it is the ball bearing at the end of the pinion shaft, just inside the pinion seal that is the culprit. This bearing is the hardest to lubricate because it is the farthest from any of the gears, and the gears sling the oil. I had my old diff and my 200SX 4.11 diff to look at and BOTH of them had a noisy bearing there, and all the rest of the bearings were fine.

You might want to see if you can pull that bearing yourself and check it. The hard part about getting to that bearing is that the pinion needs to be removed. The FSM says hit the pinion with a BFH and a brass drift. I had to press mine out. I whaled on it with the BFH and that sucker wouldn't budge. Got a press and had it out in 5 minutes.

BTW shimming the diff up is pretty easy to do too if you wanted to give that a shot. Any questions I'd be happy to help.

[ZSaint]

I am tired of working on this 240Z. I have taken it all apart and put everything back together and it is now running. I really do not want to start working on the diff. We used to take the R190's apart at the track and put in shim stock and put them back in the car. It was fun after the race day was over, having a beer and working on the car. AAACCKK! Not any more! I want to take the diff out and have someone who knows these diffs to rebuild it. I rebuilt the 5-speed, I put in new U-joints, installed CV axles and put the new engine together (can you say 'Cam Timing'?). I am a tired old man and the diff is the only problem with the car. I fixed the Corvette brakes and clutch adjustments. The diff is all that is left! Who is the MAN? :sleepy:

[260DET]

Can't help you there but its worth while looking for someone who will put the time in to get it right. Because a properly set up R200 diff will be quiet, if they are not properly done then expect noise. I always thought that they were inherantly noisy but thats not so.

[ZSaint]

I bought a press after spending $25 to have one bearing pressed off the tranny shaft. (Sheesh!) Now I have a nice press to do all kinds of things. I guess I will see if it is the front pinion bearing. If I take it all apart and put some shims in the clutches and put back together with a new bearing, it will run vey smoothly, right? Heh, heh. Don't you just love it. Working on this old Z is my life!

[jmortensen]

I bought a press after spending $25 to have one bearing pressed off the tranny shaft. (Sheesh!) Now I have a nice press to do all kinds of things. I guess I will see if it is the front pinion bearing. If I take it all apart and put some shims in the clutches and put back together with a new bearing, it will run vey smoothly, right? Heh, heh. Don't you just love it. Working on this old Z is my life!

I think it will run smoothly. I'd bet that ball bearing needs replacing, and while you're in there you can inspect all the other bearings, so you'll have a pretty good idea once you get it apart.

I don't know if you read that other thread or not, but I think about .016" worth of shim should get you to about 45 lbs breakaway. Gordon Glasgow and I both found that .020" shim gets ~100 lbs.

I didn't respond to your other request for a shop that knows R diffs because they aren't local, but since nobody else has I suppose it's worth mentioning that John Coffey sends all of his stuff to Unitrax. http://www.gearedbyunitrax.com/main.html

[ZSaint]

I sent them an email to determine the cost of a rebuild. I hate to pay for bearings and clutches when all I need (possibly) is the front pinion bearing and a .015 shim installation. Oh well, if it doesn't work out then I would just have to pull it back out and pay them to re-rebuild it!