How to: Fitting a rear Nismo LSD

Lynx

Member
I installed my Nismo over the weekend.


First thing is to get the car up.
Take off the rear wheels
Remove 32mm axle nut
Remove 24mm long Parallel link bolt (good luck)









If you break one and can't find a replacement you can use an STI bolt. They are slightly longer but just use some washers and they fit perfectly.


Remove the 24mm Trailing arm bolts
Drain the diff
Remove axles from diff

Remove breather tube from diff
Remove 4 12mm propshaft bolts
Remove 4 17mm nuts at rear of diff
Remove 2 19mm bolts from front of diff
Get ready to catch the diff
Remove other 2 19mm bolts from front of diff
Remove differential from car




Clear a work station







Remove 8 14mm bolts from end of diff and remove end casing
At this point it is a good idea to check the ring gear tooth contact with prussian blue or ferric oxide
Remove 10 12mm bolts from the side caps
Keep the Left and right parts separate and marked the shims should stay with the same side
Diff should be free now inside the case
Remove diff from case, this part is tricky, when you get it it will just slide right out. You want to stand the diff on end with the flange down. Then rotate the diff so that the ring gear is facing up and at the same time pull the diff out of the casing. If you get it right it will be easy. Don't force it. If it's not working, take it slow and think about it.






Now that the diff is out you have to swap over to the nismo diff. I had all new bearings waiting just in case, but I decided to re use the old bearings as they were in great shape and already worn in with this case.











With a bearing puller, yank the bearings off both sides of the factory diff

With a press, you guessed it, press both bearings on the Nismo diff, taking care to not mix up the left and right sides
At this point I would remove the C clips that are inside the Nismo diff. They caused problems later as they are so new and stiff, and also too thick for the passenger side shaft c clip groove I have a feeling that the ideal solution is to find nismo side shafts(good luck), but rest assured that I installed two Passenger side shafts with no problems.




After putting the diff back into the case and bolting up the side flanges, check the tooth contact again. If it is not centered I would just go to a diff shop and seek assistance, as adjusting everything is so damn complicated without the proper tools. A good nissan mechanic from the olden days would be a god send as there exists very specific tools solely for this diff, and if someone knows how to use them that would be heaven.


As luck would have it my tooth contact was beautiful. Then check the total preload. You will need a torque wrench that reads inch lbs or equivalent. Turn the pinion flange several times to make sure everything is seater properly. and put a socket on the nut inside the flange. Turn the flange with the torque wrench and watch the needle indicator to see how much force it takes to turn the pinion. Proper range is 8.7 - 13.9 inch lb. If it is too high add same shims to both sides of the case. If too small, yup, remove same size shims from both sides.

Put the casing back together.




Then go ahead and install this back on the car. If you took the C clips out make sure both driveshafts you use have c clips on them. I used two passenger side shafts, and both seated perfectly in the diff. I think you can probably chop your drivers side viscous lsd spline off and it will still work, but I didn't try it so I'm not 100% sure. Keep in mind that the two shafts use different c clips, and are slightly different lengths. They could probably be machined to work if you cant find another passenger side shaft.




Install everything in the reverse of removal. Don't forget to fill the diff with LSD oil. You can use what you like as long as it is designed for mechanical lsd. I use Subaru LSD oil for a 2004/2005 STI, as their r180 plated diff is practically a rip off of the nismo one.




Break in is recommended by Nismo as 300km of under 60 km/h driving.




Every other diff manufacturer says to drive 30 mins of figure 8's in a parking lot with no applied torque while turning (clutch in)




I did the figure 8's and you can definitely hear the diff chatter. I just kept going until the chatter disappeared (about 35 mins) If you turn while applying torque during break in you will definitely hear lots of clunking. This is the diff working, but isn't really good for it while you are breaking it in. You want the plates to wear into each other smoothly. Just like clutch break in or, brake pad bedding.






Man this car is fun to drive now. I did the Modena front on Sat and the Nismo on Sun. The Nismo Definitely added a ton of grip. In a turn when you get on the power you can just feel the car fighting for grip and the acceleration in the turns is awesome.






I have 2 autocross events this weekend, so I will post vids and impressions during some real performance driving.
 

red reading

Active Member
so you have not set the bearing pre-load nor has the back lash been set on the crown wheel? you should not just change diffs like this it is not correct and is highly likely to cause problems.
 

Lynx

Member
The only thing I have checked is preload and tooth contact. Backlash and pinion height effect tooth contact. Since it was spot on, I didn't bother taking it to a diff shop. If it kills a ring and pinion I've got 3 more, but I doubt it.

I agree with you that getting it set up at a diff shop is the best idea, so that they can check all the specs to compare to factory spec and adjust if needed.

edit: I see I forgot to add checking preload to the how to. I shall edit it.
 
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