Speedtoys

Its been said/suggested (I do not recall) that yes, you can replace the LSD gearbox in-car without much hassle..compared to replacing just the LSD pack itself which involves pulling the tank.


I have my 928Intl replacement..with about 1/1000th the hassle of any other new or used car part mail-order problem Ive ever had (Thanks guys!)..and its now a 70lb box on my step..that Id like to swap before a trip to Seattle in a few weeks...but could wait if it had to. (pinion carrier bearing going south)

Who -has- done this before, and what gotchas are in store for us?

I have a matching pinion still installed in it's original rear end housing, the matching bearing sleeve with it's appropriate and matching shims for the pinion bearing sleeve height...and new oRings for the various locations they exist..and new bolts just in case.

Other than two challenging bolts to get to, which dont SEEM impossible to get to..looks like it should..drop out, pull the bearing sleeve, install W/matching shims, and done...2-3hrs?

Alternatively, I could bring to Seattle for an install party (with beer/pizza/wings provided in mass quantities) for Sunday the 15th to entertain the dregs that didnt make it to SLC.

mark kibort

ive replaced the transmission in the S4 with Bills help. and have done quite a few LSD removals and installs with the trans in the car.
maybe i dont understand the question.

Speedtoys

Ya..just the rear end gearbox..not the tranny, it would stay in place.

My 2.54 box is bad..because the pinion is bad.


I have a matched set pinion/rear gearbox to swap in. Just wondered if there were any gotchas.

Since nothing that has any critical measurements is being pulled apart, should just swap out and in...from the pinion carrier on back.

Stromius

Speed are you doing this in Norcal, CO or NW??

mark kibort

if the main drive pinon is ok, then its not a big job. just shimming it correctly is the only gotcha.
ive never done it myself , but the monkey's at CT have done it a few times for me and scot.

IcemanG17

Since you must replace the pinon and ring gear....I'd pull the whole thing.....its one of those things that "should" be possible, but typically ends up taking MORE time than the obvious answer....

Bill and I did manage to change my rear main seal with the engine in the car....but it was quite frustrating lying on your back for hours messing with that DAMN seal.... Since I know I can pull my racers engine in 3-4 hours....thats what I SHOULD HAVE done....8 hour job quickly became 2+ days of frustration....

Pulling the trans requires dropping the suspension too...which is a PITA....but Evil Genius Racing did it in the Estate for 8 billed hours or $680....($85 per hour).....they could do yours too no doubt...would be easy since they already did the Estate last January....took the 84 open diff out and installed the 88 S4 LSD....

Speedtoys

I live here in Norcal. But failing scheduling it done, I will be in Seattle for 2wks starting the 8th.

Speedtoys

I have the whole bearing carrier for the pinion..and the matched rear-end for it..and the shim for -that- bearing carrier right here. Thats the only adjustment..and its not changing going from one tranny to another.

Speedtoys

Yes, but the ring and LSD unit stays in the rear end gearbox..it doesnt dissassemble.

5 or 6 bolts hold this to the tranny...and its off.

Then a gear puller for the pinion carrier.

IcemanG17

True...but I am worried about INSTALLING the new pinon to the correct tolerance......its extremely precise.....and the consequences of getting it wrong are PRICEY...pay a shop and they get it wrong.......THEY fix it......do it yourself and get it wrong......$$$$ to you

Speedtoys

There is no tolerance to install to.

The height of the pinion sets the shim..which is part of the matched set I have here.

What tolerance needs set, if nothing with a tolerance is being disassembled?

IcemanG17

Its possible I am incorrect.....but ring-pinons are machined together (duh)....but there might be slight variance in the diff housing that requires precision....not impossible, just care needed during install to make sure everything is right

Remember the ring pinon you have was machined together and drove for ??? miles in a diff housing you don't have (or do you?).....Even still there probably is slight variance in the transmissions location of the pinion too...

Speedtoys

The pinion bearing carrier (960 302 063 09) can be off, which is why the pinion depth is set by shim 960 302 063 0x, which is set by determining the assembled height of the carrier in section 39-29, and this is not changing. That carrier and it's shim are here with me...a well as the fully assembled rear end gearbox that the ring & LSD are within. The shims are re-usbale as long as the same bearing assembly/carrier is still used.

And in the chart, shim 960 302 063 0x shouldnt need replaced for replacing the differential case...as that shim is matched to the transmission case length..to shim out the diff case, and the pinion is set by the matching shim..that came with the matching HW.