factory Viscous LSD going bad?

[Brettt]

So.... I pulled the transmission and have taken it apart. It looks fine. There isn't a bad bearing on the output shaft like we had hoped and the spider gears in the LSD seem tight. The fluid we drained out of it has little pieces of what appears to be a hard bearing-type material and the drain plug had some larger pieces stuck to it. One of the pieces was even a skinny shaving that looked to be 1/4" long. I'm trying to get some pics of the gear stacks and other internals to show you guys, but I'm not sure how helpful pictures will be when it seems to look good.

Not really sure where to go from here considering we have new hub bearings, new halfshafts, and the transmission doesn't seem to want to show me where the metal pieces came from. And with the new hubs and halfshafts we had the worst vibration ever when we tried to run at Topeka. So to sum it up, everything but the transmission internals are new, the same internals don't show bad wear anywhere, and the vibration is worse than ever.

Please help!

[Matt93SE]

Maxima trannies are really bad about eating input shaft bearings. have you looked closely at them?
http://blehmco.com/pics/car/drivetra...y/IM001410.JPG

I don't think that would cause your problems, but you never know...

another thought is to check the play on the diff.
Since you have the case split, drop the diff back in with the bearings and put the case back together. check the axial play on the diff while the case is together.
I wonder if the final drive is rubbing against 1st gear..
http://blehmco.com/pics/car/drivetra...y/IM001408.JPG
(That's my Maxima tranny, but yours probably isn't much different.)

[Brettt]

another thought is to check the play on the diff.

After scratching our heads for a while, we decided to put some axle stubs in the VLSDs from both trannies and see how they turned. The unit that came out of the car basically spun like an open diff. with the added benefit of being really notchy... I think we might have stumbled across the problem. The donor transmission had another stock unit that actually worked like an LSD and didn't produce the bumpiness of the other one.

Right now the case is back together and we're going to have it on the car shortly. Hopefully it'll still be light and we can test it out, but if not there is an open track day tomorrow for more testing.

As always with this mystery vibration, going to keep the fingers crossed!

[Brettt]

Thanks to a donor transmission differential and a deepened inner CV joint the Sentra rides again! That, coupled with the suspension changes I've made gave me some of the fastest laps I've ever run at MAM this weekend. It was a little slick from the rain but still handled great after some suspension tweaks. I swapped the springs around to 560lbs in front and 700lbs in the rear and once i started to get a handle on where the set the dampening, it really started to rotate and fly. I had a ton of fun!
Big thanks to Damian at http://findtheline.com/ for hosting an awesome event!

Thanks for all of the help everyone, it is awesome to have a working car again!

[Greg Amy]

Good news! Now keep your eyes peeled for one of those discontinued NisMo LSDs, as you'll eventually want it. Second choice is one of the discontinued Quaifes.

Personally, I'd try fitting in a spider diff from something else (could not tell you what would fit, though) and weld it up. You've got power steering, drive it like a big boy!

[ramoncito89]

Good news! Now keep your eyes peeled for one of those discontinued NisMo LSDs, as you'll eventually want it. Second choice is one of the discontinued Quaifes.

Personally, I'd try fitting in a spider diff from something else (could not tell you what would fit, though) and weld it up. You've got power steering, drive it like a big boy!

I started racing with open diff and drove a friends SR with nismo LSD at the track and decided to weld mine, the feeling is great as long as you don’t decelerate in the middle of a corner and the car gained .3 seconds per lap over an open diff.