Help diagnosing my LSD notchiness

[RLJett]

Hello everyone...I was told by the prior owner of my vehicle that he installed a Quaife LSD. I have confirmed that the differential has been replaced with 2.82 gearing (not sure where it come from though...does the "023" stamped on the drivers side mean anything?). So I'm assuming I actually do have an LSD.

Anyway, while turning (mostly to the left) from a stop, I feel a notchiness from the differential. It is not always notchy, but when it is, you can certainly feel it. I'm wondering if maybe the incorrect gear oil was used by the prior owner? Or is this just how this LSD works (I just read a post from Dave where he described this notchiness and indicated it was normal during initial break-in?)? Should I try swapping out the oil and if so, with what? I recall some posts where there was some debate on which type of gear oil to use but I have not been able to track these down again.

 

[gsxr]

The Quaife should not have a notchy feel. The factory clutch-type LSD can have a notchy feel though. Unfortunately it is very difficult to tell what type of LSD is installed, without removing the diff from the car and pulling the rear cover. The problem is that for the clutch LSD's, you need to be more careful about which gear oil to use. The Quaife will work fine with any oil of the proper rating/viscosity (usually 75W-90 or thereabouts). If you have the time & tools, I'd consider pulling the diff to find out for sure what's inside there...

 

[RLJett]

Thanks as always Dave. Depending on how much disassembly is involved I may be able to tackle this. Do you think the differential could be dropped enough to pull the rear cover by only removing the bolts that secure it to the chassis and leave the prop shaft and drive shafts intact?

 

[gsxr]

Thanks as always Dave. Depending on how much disassembly is involved I may be able to tackle this. Do you think the differential could be dropped enough to pull the rear cover by only removing the bolts that secure it to the chassis and leave the prop shaft and drive shafts intact?

Basically... no. The way the diff sits in the subframe, it has to come completely out of the car in order to remove the rear cover. The worst part of the job is accessing the two bolts which clamp the driveshaft center support to the frame, these are buried behind the catalyst heat shield. You have to loosen those to let the driveshaft move forward so the flex disc will separate from the diff. Otherwise, everything unbolts and the diff drops out. Don't forget to unplug the ABS wire, btw, from the round connector at the floor.

If you find a Quaife (or RENNtech Gleason-Torsen diff) inside, and plan to use synthetic gear oil, don't use the factory blue Hylomar sealant for the cover. It doesn't hold up in the long term with synthetic lube. I learned this the hard way. I'm trying the black MB sealant now (supposedly the same as "Right Stuff"). If you find a clutch-type diff and plan to use the OE MB gear oil, then the blue factory sealant is ok.

 

[sheward]

I've sent you a pm.

drew

 

[gsxr]

Forgot to mention - if everything goes smoothly, it's about 2 hours to remove, and usually less time to re-install.

 

[RLJett]

Forgot to mention - if everything goes smoothly, it's about 2 hours to remove, and usually less time to re-install.

So multiply by the newbie factor of 3x and maybe I could get it done in 6 hours. Wish I had a lift. This is the first car I'm trying to work on (other than brake pads/rotors/fluid and air filters) and starting to see how much more difficult things can be without a proper setup. Oh well. Still learning, just at a slower pace. Thanks again.