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Diy:diff Shimming For R33 Gtst

Trust33

By Trust33,
in Tutorials / DIY / FAQ

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daineisdabomb Collaborator

daineisdabomb

Posted
Posted

DO NOT TRY THIS AT HOME!!!!!!!!

i think u forgot to tell ppl that they need a diff housing spreader to get the centre back in as it simply wont go in without 1. the tolerances need to be perfect and there needs to be literaly no play in the diff which can only be done by spreading the housing to allow all the spacers to go back in. i learnt this the hard way by attempting this tutorial. now my centre wont go back in!!! gggrrrr very angry now my car is stuck and i cant move it till i get a diff place to put the centre back in. aahhhhhhhhhhhhh

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Cubes
Cubes

Simply add the new shim to the existing shims. I usually remove the diff by: 1. Drop the sway bar chassis mounts, leave the risers attached. 2. Remove tail shaft. 3. Remove Half shaft bolts (have

Rolls
Rolls

It is just shims, they can be easily removed or changed. No need to find a whole new diff.

Bauerpower
Bauerpower

For the first time in its life my 33 has finally seen some decent hp after a turbo upgrade (gt3076 on 20psi) and an ecu of course. Not to my surprise the LSD had no chance at doing its job and started

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donut_kng Experienced

donut_kng

Posted
Posted
DO NOT TRY THIS AT HOME!!!!!!!!

i think u forgot to tell ppl that they need a diff housing spreader to get the centre back in as it simply wont go in without 1. the tolerances need to be perfect and there needs to be literaly no play in the diff which can only be done by spreading the housing to allow all the spacers to go back in. i learnt this the hard way by attempting this tutorial. now my centre wont go back in!!! gggrrrr very angry now my car is stuck and i cant move it till i get a diff place to put the centre back in. aahhhhhhhhhhhhh

dont be soft mate just give it a bit of a tap and she'll be rite then once you can get the threads going on the cap bolts slowly do them up simultaniously.

  • 1 month later...
33drifta Community Regular

33drifta

Posted
Posted
DO NOT TRY THIS AT HOME!!!!!!!!

i think u forgot to tell ppl that they need a diff housing spreader to get the centre back in as it simply wont go in without 1. the tolerances need to be perfect and there needs to be literaly no play in the diff which can only be done by spreading the housing to allow all the spacers to go back in. i learnt this the hard way by attempting this tutorial. now my centre wont go back in!!! gggrrrr very angry now my car is stuck and i cant move it till i get a diff place to put the centre back in. aahhhhhhhhhhhhh

its a hard job but i managed. who ever told you you need a diff housing spreader is full of shit. i didnt use/need one. like donut_kng said, dont be soft :thumbsup:

  • 2 weeks later...
axe s Experienced

axe s

Posted
Posted
DO NOT TRY THIS AT HOME!!!!!!!!

i think u forgot to tell ppl that they need a diff housing spreader to get the centre back in as it simply wont go in without 1. the tolerances need to be perfect and there needs to be literaly no play in the diff which can only be done by spreading the housing to allow all the spacers to go back in. i learnt this the hard way by attempting this tutorial. now my centre wont go back in!!! gggrrrr very angry now my car is stuck and i cant move it till i get a diff place to put the centre back in. aahhhhhhhhhhhhh

I had this problem (Mine went in but very hard)...

Pull it out and put it together again... mine wasn't lined up properly (didn't put the half shafts through before i put it together...)

Second time it just dropped in...

donut_kng Experienced

donut_kng

Posted
Posted

just thought id post my results..

first went a 1.49 + 0.8 on each side and was ridiculously tight (I did this before I knew this thread existed!)

then I went town to just the 1.49 on each side and it was nice but still a but clunky on the talkshaft off throttle,

today I wacked in a 1.20 on each side and it basically feels like a fresh stocker, which is a but soft cock for my liking.

My next go is either 1.3 or 1.4, I am undecied but leaning towards the 1.4

Does anyone know if having different sized shims on either side (i.e 1.49 on once side and say 1.20 on the other)) have any affect besides making a 'custom' total pre load thickness?

  • 2 weeks later...
  • 2 weeks later...
jester_oh Explorer

jester_oh

Posted
Posted (edited)

Heres something that hasnt come up yet here . oils . seeings as its not technically on topic HERES a linky to something i found interesting while researching to do this mod.

Ive only been looking at this recently and im not what i would call knowledgable on this topic but the viscous lsd is a clutch . The plates of the clutch never touch , the thin coating of oil between the plates which prevents them from touching either heats up or reacts somehow , to the friction , whilst cornering and increases that friction further.

It sounds to me that the "problem" that the guy in the linked thread had may just be what were all chasing here.

i had a 75w-140 in my diffs a while ago (redline) and cause it was too heavy it created a shudder in steering at low speed turning

maybee its a matter of going to around 2.8 mm total preload and then if its a bit too soft on the cockometer whack in some heavier oil .

Apparently

you want a 80W-90 LSD oil

as standard .

Heres a link to another tutorial . Its for a datsun site but it has an interesting comment down the bottom that i believe applies to us

It doesn't in any way tighten up the viscous unit as these are a sealed, non serviceable unit. This puts more tension onto your spider gears making them not want to turn so easily, and so it will cause your diff to wear more. Its a fine line between tightening it and ending up with a complete locker. It all depends on the condition of your diff of coarse but looking at others feed back anything over 1.5mm of extra shims results in a complete locker.

This changes things again and even more so makes me think that the (75w-140)oil may bring your diff back to life (if your after a streetable good lsd) rather than this method of shimming for an almost ON OFF switch for LOCKED or UNLOCKED diff .

What oil have ppl been trying ?

Edited by jester_oh
  • 3 weeks later...
psi Experienced

psi

Posted
Posted

In a normal clutch or cone type LSD like a borg warner, that would probably be the case..

however, the Nissan LSD pack is sealed. I cant see the merit in going to a heavy oil other than slightly changing the drag on the star gears..

My 2 standard diffs ran 2.1 and 2.4mm shimms all up. So I gave it 3.3mm shimms all up. The diff was all but locked 24/7! was somewhat unfreindly in carparks and servo's. I reduced it to 2.6mm and it one legs EVERYWHERE..

I will be trying 3mm next to see if I cant get a nice result.

jester_oh Explorer

jester_oh

Posted
Posted (edited)

ive just had mine out and i see what you mean about the clutch in there being sealed . i think your right the oil should have no noticeable impact .

just to add to the info available i found in my diff an

0.8 mm washer and a 1.5 mm washer for a total of 2.6mm . it drove very nicely , didnt single spin ever as far as i could tell . (feeler gauge is what i used to measure , there cheap)

i purchaced 2 1.1 mm washers with the plan to jam anything i could in there to lock it up tight for drift work . I could only fit one of them in there for a total of 3.4 mm as theres only so much you can fit in before the 2 screws that hold it together start to look too weak to pull the thing back together .

end result is a win for me , nicely locked up with no real movement . i think occasionally i can hear the spider gears moving half a tooth but it may be the tyres too . drift practice in 3 days woooo.

Edited by jester_oh
  • 3 weeks later...
daineisdabomb Collaborator

daineisdabomb

Posted
Posted
dont be soft mate just give it a bit of a tap and she'll be rite then once you can get the threads going on the cap bolts slowly do them up simultaniously.

nah it just wouldnt go in how hard i tried, i ended up bending one of the big shims that adjust the backlash. i almost ripped my hair out!!! can someone put some pics up of how they got the centre back in??? step by step plz.

  • 2 weeks later...
daineisdabomb Collaborator

daineisdabomb

Posted
Posted

ok i pulled my diff apart again on the weekend (AND GOT THE CENTRE BACK IN THIS TIME LOL) to change the shims coz it was way to tight (well locked all the time) and it was very annoying with 2 1.3mm + 1, 0.8mm shims (3.4mm total). so newayz put 2, 1.1mm shims in. very smooth to drive but back to its unpredictable ways. locks while accelerating hard in a straight line but wont whip nutz nemore and locks/unlocks while turning heavily with foot flat. i hav come to the conclusion. ITS EITHER LOCKED OR LIKE A STOCKER SO BUY A MECHANICAL LSD OR PUT UP WITH IT BEING LOCKED ALL THE TIME or not locked and unpredictable....... and thats my 2 cents worth lol.

  • 1 month later...

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