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Diy:diff Shimming For R33 Gtst

Trust33

By Trust33,
in Tutorials / DIY / FAQ

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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

Posted Images

W0rp3D Grand Master

W0rp3D

Posted
Posted
can someone in perth tell me were they orded theres from i cant find any nissan spare parts web sites that have it?

tried nissan?

Or maybe a diff place. ring and ask them where they get theres, teh intranets is not always the answer.

psycodelik Apprentice

psycodelik

Posted
Posted

Order them from nissan, the part numbers on the first page are correct and their called thrust washers, not shims, i bought 2 1.5mm shims and it cost me 16$ total,

also AWESOME tech guide, greatly appreciate everyone for contributing

  • 2 weeks later...
33drifta Community Regular

33drifta

Posted
Posted

ITS someones LUCKY DAY in melb if your thinking of doing this!!! im selling my car and need a stock (un-shimmed) diff. i did this mod to my diff (read back in this topic to see my thoughts). mine is nice and tight still and going strong as ever. give me your stock (working) diff, and you can have my already to go shimmed diff! pm me or call me 0400119068. cheers, Shane.

  • 1 month later...
na beast Community Regular

na beast

Posted
Posted

Shimmed mine to 2.8mm preload just died last night after only 3 weeks :S

Doesn't sound right to have only lasted 3 weeks so going to have to take it apart again and take a looksie.

Definitely going for more lock this time tho.

James

  • 2 weeks later...
  • 5 weeks later...
  • 4 weeks later...
-Jimmy- Mentor

-Jimmy-

Posted
Posted

I'll just let everyone know, I learnt a LOT while doing this.

I ended up using a 1.05mm shim, and 1.40mm shim (2.45mm all up) and I drove my car for the first time tonight and it is completely locked.

I certainly wasn't expecting it, as I was already running 1.95mm and I thought .5mm won't make a heap of a difference.

Also while reading the thread people using 2.6, 2.7 and 2.8 never seemed to end up with a locked diff. I'm quite stumped to be honest.

I either did it really right, or really wrong. I am using Castrol VMX90 oil.

The behaviour of the car is dramatically different, and even on slight bends you can feel the car wanting to push forward rather than easily coast around the corner.

I'll let everyone know how it feels when it has settled in.

-Jimmy.

  • 4 weeks later...
-Jimmy- Mentor

-Jimmy-

Posted
Posted (edited)

That doesn't make sense. That would equate to exactly 3mm of preload? I put 2.45mm in mine and it skips the inside wheel on full lock when parking.

I've driven mine for a few weeks now and it's definitely loosened up. It's probably the best I could ask for, still good for the street but very tight and predictable.

Edited by -Jimmy-
  • 1 month later...
NMD Explorer

NMD

Posted
Posted (edited)

it will depend on how worn the diff is. more wear to the spider gears the larger the shims need to be. can also depend on the oil you use as well.

in my cefiro ive used around 3.2mm of shims as well as 140 weight oil....... the diff was worn out before the shims, would only spin one wheel, but now it doesnt have a choice, its both every time and chirps doinf u-turns.

which is fine because its my drift car :ermm:

Edited by NMD
  • 1 month later...
Mr. Untouchable Experienced

Mr. Untouchable

Posted
Posted

just fitted another diff into my 33 gtst. I purchased a second diff so I could work on one without pulling out my orginal, plus I have a spare housing so when I do finally get a 1.5 way I can slot it straight in.

anyways I pulled the new diff down, very clean and very good condition. It already had a 0.8mm shim plus a 1.4mm shim, so it had been done before. I added another 0.8mm shim to this. So all up it has 3mm of preload. just put some 80-140w nulon high performance oil in it and took it for a lash over some twisties. I'm really impressed with it, very predictable. It's pretty damn tight, kinda mini spool spec doing a 3 point turn but its not too bad.

for the money/effort I think its a excellent mod. Very impressed

  • 4 weeks later...
  • 4 weeks later...
  • 2 weeks later...
Rolls Grand Master

Rolls

Posted
Posted (edited)

Has anyone considered changing the actual viscous fluid in the LSD centre? As changing the preload is really just a tightass hack that won't really work that well. It either locks or open wheels sort of thing, no middle ground where its like 50% locked. The only time you could achieve the nice medium is if your diff was still in good condition and not completely open wheeling.

I've heard of people putting thicker fluid in the viscous centre in 300zx's etc so surely it can be done here, is the centre serviceable, like can it be unbolted and pulled apart? If so it would just be a matter of finding out what fluid is currently in there and replacing it with something thicker.

Anyway let me know if anyone has done this before or knows if the oil can even be changed.

edit: Perhaps I am wrong but I am assuming that the diff centre is sealed and uses a different oil to the actual diff crown and pinion, if not could we just experiment with putting thicker oil in the diff itself? Would make the car slightly more sluggish, but might make a big difference.

Edited by Rolls
W0rp3D Grand Master

W0rp3D

Posted
Posted
Has anyone considered changing the actual viscous fluid in the LSD centre? As changing the preload is really just a tightass hack that won't really work that well. It either locks or open wheels sort of thing, no middle ground where its like 50% locked. The only time you could achieve the nice medium is if your diff was still in good condition and not completely open wheeling.

I've heard of people putting thicker fluid in the viscous centre in 300zx's etc so surely it can be done here, is the centre serviceable, like can it be unbolted and pulled apart? If so it would just be a matter of finding out what fluid is currently in there and replacing it with something thicker.

Anyway let me know if anyone has done this before or knows if the oil can even be changed.

edit: Perhaps I am wrong but I am assuming that the diff centre is sealed and uses a different oil to the actual diff crown and pinion, if not could we just experiment with putting thicker oil in the diff itself? Would make the car slightly more sluggish, but might make a big difference.

the answers to you questions are in this thread, read it.

mark33gtst Community Regular

mark33gtst

Posted
Posted
I read every page, or at least I thought I did, no one mentioned opening up the actual centre and changing the viscous fluid.

The center is not sealed.. Uses the same oil as the rest of the diff.. You can change the oil to a thicker oil but it doesn't last.

Rolls Grand Master

Rolls

Posted
Posted
The center is not sealed.. Uses the same oil as the rest of the diff.. You can change the oil to a thicker oil but it doesn't last.

What happens, only makes a slight difference? What if you almost double the thickness of the oil?

Probably wear the components faster and make the car ever so slightly slower, but be interesting to see the effects on the LSD.

  • 4 weeks later...
jester_oh Explorer

jester_oh

Posted
Posted
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.

update .

been drifting for over a year now . no issues . fully locked . no noises ever just tyres doing there thing .

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