Diy:diff Shimming For R33 Gtst

[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 some one in the car operating the hand brake for the exhaust side as there's little room) Use the old ringy with a spanner end + another ring to get leverage trick.

4. I drop the hicas down a touch via its 2 bolts so I can easily get to the diff rear nuts

5. Remove the rear diff mount nuts

6. Place the std sizzor jack under the front of the diff to hold it up

7. Remove the front diff mountings

8. Loop a piece of thin rope around the subframe and under the rear to middle of the diff and have the rope sticking out the wheel arch tied to a piece of wood to hold on too

9. As your mate or other half in my case slowly lowers the diff via the rope wind down the sizzor jack and wiggle the diff out past the exhaust etc.

When removing the diff center from the housing with a small jimmy bar (supercheap have $8 ones) make sure you take a photo or something of how the shims under the main caps are positioned. I mark them with a white paint texta.

Don't forget to remove the half shafts before attempting to lever the center out lol... Not quite sure what I was thinking, I'll blame it on being tired. The short half shaft may be really stuck in there, I use an extension bar with a rubber mallet through the center of the diff. Just be sure to be carefull when positioning it.

Getting the diff back up in to the cradle... Its a heavy bastard so use the rope to help lift the sucker up, I first lift the front up and sit it on the sway bar, then with the help of my other half with the rope in her hand I lift and wiggle the center back in.

TOO easy..

[sinistaGTR]

cheers cubes might go to main north if i get time today and order my shim lol

[Trust33]

mine is still chirping on the tight corners but has worn dow a fair bit.But hasnt lost the lsd effect,and still has the bind/unbind happen.like yours cubes.

When it was first done though it was tight as can be.If you have probs geting the lsd back into the housing use nthe bearing caps to guide it back in.dont go bashing the lsd .Aslo remember the way( up/down) + direction they and for that matter everything goes.

Judging from the shim size that i had you could prolly go slighly bigger,though i wouldnt take it past 4mm of preload cause it will be a hard focker to get back into the housing.Also get the little phillips head screws screwed as tight as you can before the crown wheel and 10 bolts go back together.Use loctite heat proof one on the bolts and the rest of the assembly,let it cure then u can think about filling it back up with oil.

If you need help though keep the questions coming.

[Trust33]

My diff has tamed down since its first inception.But it still locks well.Maybe everyone needed a little more than just a stock shim thrown back in there.Both sides are better by the looks of it.

[SECURITY]

wouldnt it be better to remove the old shim then put in a thicker one?

wouldnt just adding a shim cause slip between the old and the new?

[Cubes]

I've found the 2 shims side by side still take out the increased preload on the housing.

Mine chewed away at it quite considerably. You could also see how the spider gears were binding from the metal squashed look on the spider gears.

If that makes sense

[SECURITY]

ok but say i wanted to be 100% sure there was going to be 0 slip.

what thickness shim would you recommend if i took the old one out and replaced it with a single one?

[Trust33]

there arnt ones that thick.

i can see where you are coming from.1 instead of 2 so there is no possible way of slip between the shims..

the biggest shim is 1.49mm thick.

making 4mm of preload will be hektik as,1-1 lock for sure.especially when new.then it will wear down but will stop and stay their at a certain point as has mine.wile mine is 3.2mm off the top of my head it is still a good predictable diff even after being daily driven since it has been installed.

when mine was first done it was 1-1.now more like 1-.80.

im not to sure,but what side you shim may have an effect on which direction the preload will affect.!!just going out on a limb here!!

wait now i thinkl about it it prolly really doesnt have an effect on which direction the preload will affect. there is no real gearing that would allow a differing change over in tourque from foward to reverse.its prolly right to say the tourque preload is the same foward to reverse.

[SECURITY]

yeah but diffs that are open wheeling compared to diffs that arent so bad will have different wear on the shims. what im saying is - is there a certain shim size i can use to replace so i know it wont slip at all?

can i use a 1.49 on 1 side and a 1.49 on the other, making it 2.98 in total. will that work?

i just dont like the idea of 2 shims up against each other.

[Cubes]

When I pulled apart my center after being shimmed the shim actually ate away at the center/casing. :S

After removing the shim and bolting it back togethere there was a shiet load of spider gear slack.

Ideally you want the shims to slip and apply as much preload on the spider gears as possible.

[Trust33]

Ideally you want the shims to slip and apply as much preload on the spider gears as possible.

yeah i think that the diff will definently spin up 2 wheels with 1.49 each side.consider that a stock diff has 0.8 each side stock and was considered a lsd when new.

1.49 both sides will be better at lock than when it was brand new.

[SECURITY]

alright so what sizes would you recommend for a single shim on each side?

[bloodsword27]

heya how have you found the durability of your diffs now that you have the shims in? dont really want to be going through 10 diffs a year...

[Trust33]

heya how have you found the durability of your diffs now that you have the shims in? dont really want to be going through 10 diffs a year...

my diffs good mate.

daily driven as well.

alright so what sizes would you recommend for a single shim on each side?

the biggest you can get.

1.49mm

[Trust33]

1.not that i have had much experience in the field.im not a mechanic.i went for 3.2mm as an experimental guess.it is great for drifting but it draws attention to your car on tight corners with chirps.

ive heard that if you go to little on the shim when it wears down in the first few months,and it will,its kind of like a bedding in process it goes through.so dont go to small.id say if you want it to still be a decent streeter/drifter style diff.take it close to 3.0mm at least.it will feel really tight at first for a few weeks.

you could probably get away with 1.49mm shims on either side and sell or give away the stock shims.

2.buy them from nissan spare parts.as far as i know they are only sold by them.ive been to the uxual repco,supercheap and the like and they all couldnt get them for me.use the part numbers that i provided in the 1st post to get the exact size you want.

3.do it if you are going to get into motorsport.imo it is a waste of time and effort,and it can draw unwanted attention to you on the street,doing it for any other reason.

enjoy it

[33drifta]

hey all, i just shimmed my diff on the weekend and thought id tell u all how it went and how my diff is now.....

well it was all straight forward to do thanx to the awsome step by step instructions thanx to trust33, thanx man. however, it took farkin ages due to how tight all the bolts were. i bashed my arm like 5 times in the same spot, skined knuckels and i even bashed my head on the concrete when i put all my might in2 undoin a bolt and it broke free and i went flying lol. the bolts were so tight even my mates rattle gun didnt undo them, i had to use a vice and hammer for those 10 bolts inside the diff. was it worth it u ask, f*k yeh it was. my diff went from single spining all the time to a locker at the moment, i hope it wears in and stops chirping and bouncing around ever corner soon. i replaced the two .8mm shims with 1.49mm shims and its TIGHT as now. the car feels solid as on the road and if i give it to her she steps out nicly, much easyer to control now. i recomend if u are going to do this defenently have...1, a good large vice..2, a mate to help u lift it in and out cuz its heavy.. and 3,lots of paitants cuz it gets frustrating. thanx trust33, i'll let u know how it wears in, in about a month and good luck to anyone that atempts it, its not hard but took me about 7 hours cuz of all the tight bitches.

[Trust33]

no worries shane.glad to hear it all turned out well.

those bolts are the worst part of the job hey.i had a breaker bar and a mini 5 pound hammer at it and every time 1 bolt was loosened i would have to retighten the lsd back in there because it was slipping in the vice.haha.

[33drifta]

yeh man the same thing was happening to me. i had this shit little vice to work with aswell. i was so ready to give up but id come to far to just put it all back without finishing. today was the first day of driving in the wet and it was sweet, so much more control now. very glad i did it but i hope it stops this chirping around tight corners soon, how long did it take your to wear in?

[Cubes]

Definitely need a decent air rattle gun to get the bastards off. Old man has a dewalt rattle gun that got my first diff centers bolts off. But only just. The second center it was only able to remove a few of them. A trip down to the local mechanic and he rattled them off for nothing.

[dead32]

orderd my shims today, i orderd 2by 1.49 shims. lookin at puttin 1 either side.. ill post up once installed.

p.s i got them cheaper then advertised here? duno how like $5 each.