How Do I Tell If My Diff Is Fcuked?

[Shaun]

Hi,

Since i completed my engine conversion, ive kinda been going for long drives away from civilisation and having a bit of fun. Ive discovered that my rear wheels are spinning more often than not due to ridiculous power for a rear wheel drive. When i look in the rear vision mirror, however, i can only see one black line, and my passenger side rear tyre is wearing significantly more than the drivers side.

Im wondering if my diff is worn and is now single spinning. Or is it that my weight on the drivers side is enough to keep the drivers side from spinning?

Is there any simple way of checking weather my diff is worn? Also, what are my options for freshening the diff up? Can they be reco'd fairly cheaply?

This is an area that i know little about. Its an R32 gtst R200. Oh, and please no comments about hooliganism. Im sensible about it and do it when no one is around.

Thanks,

Shaun.

[GTScotT]

as the cars are getting pretty old now the diff is proberly warn, mine leaves 2 nice marks everywhere i try.

and yeah regardless of how far away from civilization you go, unless its private property watch out cause police also go there to find people who they can book

as for your options, you could possible rebuild your stock diff, or you could go to an aftermarket diff, or even find a cheap r32 gtr diff 2nd hand

[Shaun]

Are gtr diffs better than gtst diffs? I thought they were all R200, but clearly im no expert.

I think i'd opt to rebuild the stock diff, as they seem like a pretty good piece of gear.

[Morgs]

I'd look at getting an aftermarket centre into it with that kind of power

[Shaun]

Right. Ive really got no idea where to start. Ill have to do some research. Any of you guys know of any diff gurus that i can call for advice and quotes?

[some_cs_student]

If you jack the car in the air, and turn one wheel, the other wheel will spin in the opposite direction on an LSD diff.

In my car, if you spin one wheel a little, the other "locks" after a while, and then they have to spin together or not at all, eg. get someone to hold the other wheel....and try and spin the opposite side.

The above will work on a tight LSD...the one black line does sound like it might be slipping, you can get new shims for the LSD's from Japan I believe or a diff re-builder may have them.

EDIT: Stock GTR diff's can be very tight after shimming, and fairly cheap for the R33's, but not sure about the r32 diff's. Also, GTR's pinion/crown wheel would be a different size (diff housing?) wouldn't it? <-- too technical for me

[Shaun]

Yeah, ive just been searching about the different diffs (1.5 and 2 way), and i can see the dollar signs already. Im after a fairly cheap alternative; maybe a 23gtr diff with the kit from Nismo.

I dunno.

[Shaun]

Ive been doing a bit of ringing around, and discovered that a complete R32 gtr rear end (from disc to disc) is about $1000 from SSS. The only thing that im worried about is the length of the rear drive shafts. The guy at SSS said that the gtr shafts are 40mm longer than the gtst ones, and he wasnt sure what people do about this.

Can anyone confirm that the shafts will fit without problems? Also, ive got DBA rotors on the rear of my car atm; will i still be able to use these with the gtr rear end?

Thanks in advance,

Shaun.

[cuppas]

If you jack the car in the air, and turn one wheel, the other wheel will spin in the opposite direction on an LSD diff.

In my car, if you spin one wheel a little, the other "locks" after a while, and then they have to spin together or not at all, eg. get someone to hold the other wheel....and try and spin the opposite side.

theyll spin opposite directions with an open diff... LSD spins both same direction

[some_cs_student]

theyll spin opposite directions with an open diff... LSD spins both same direction

Yes, your talking when putting power down, I'm talking about in the air.

Open diff would not need to spin the other wheel at all, it would be open with little resistance.

[dano4127]

Mine is starting to feel a little warn now too, I am going to try shimming it up before i even consider aftermarket

have a look in the DIY section for info or take it to you local dif guy even your mechanic should be able to shim it up

[Shaun]

Yeah but everyone ive spoken to about it says that they can shim it up no worries, but ill just start open wheeling soon after. If i had standard (or close to) power thats exactly what id be doing, but i dont think the viscous diffs like over 300kw.

[CEF11E]

i shimmed my stock lsd nearly 3 years ago and it was great for less than 2 weeks untill it started to open wheel again. i pulled it apart and it had cooked the viscous coupling and had fine metal paste all through the oil.

not reccomended.

I fitted a nismo sss housing in my centre and it always plants both down even when you don't want it to. clunk clunk clunk in carparks. and sideways action in the wet. also understeer pushing you into corners..

if you are going to get a mechanical diff...

1. if you are going to driver it on the road get a 1 way (only lock under acceleration)

2. wear it in properly... dont go drifting on it the day you install it as this will fcuk it big time

3. use the right oil with a limslip additive

you can buy a centre and have it fitted and set up in your diff for $1500

dont shim the stocker its a shit option. its cheap and works for a small amount of time before it f*kcs the diff

[Shaun]

^^^^^ Yeah, thats what i was told, so i'd rather do it right the first time. My car is street driven 99% of the time (although i only drive it once or twice a week, and NEVER in the rain - god forbid), but i think ill go a 1.5 way.

Im really interested in the Cusco RS, but im still waiting on prices from Greenline. The Nismo LSD Pro TT model is too expensive.

It seems no one can beat Slide's prices of $1040 delivered for a Kaaz diff, but im having trouble finding info on them other than generic marketing stuff. I really really dont want an obnoxious diff for everyday driving.

Has anyone had experience with both the Cusco and Kaaz diffs? Are they ok on the street if you use the right oil and bed them in ok?

Shaun.

[Beer Baron]

GTR diff is a good option for street use. they are a mechanical 2 way LSD standard and are tough as all buggery. the $200 clutch upgrade from nismo turns them into what is basically a nismo mech diff. plus the GTR rear end is better too (bigger axles, alloy hubs). be aware if you do the complete GTR rear end that rear GTR lower shock mounts are different than the 32 GTST type. (GTR shocks have fork, vs eye for GTST).

aftermarket centre into your current diff is the easiest option. GTR diff and rear end is the more compelte option. up to you.

[NWR31]

Yes, your talking when putting power down, I'm talking about in the air.

Open diff would not need to spin the other wheel at all, it would be open with little resistance.

no he would be talking when wheels off the ground, cuppas is right, you are wrong.

cheers

[Shaun]

GTR diff is a good option for street use. they are a mechanical 2 way LSD standard and are tough as all buggery. the $200 clutch upgrade from nismo turns them into what is basically a nismo mech diff. plus the GTR rear end is better too (bigger axles, alloy hubs). be aware if you do the complete GTR rear end that rear GTR lower shock mounts are different than the 32 GTST type. (GTR shocks have fork, vs eye for GTST).

aftermarket centre into your current diff is the easiest option. GTR diff and rear end is the more compelte option. up to you.

Thats the info i was after Mr Barron, thanks for that.

Ill opt for the aftermarket centre i think; especially since the gtr lower shock mount is different, as i just installed new Bilsteins and set them up. $1000 for all the gear (from SSS) + $200 for the clutch upgrade + screwing around with my rear shocks = aftermarket centre for me. Just got to decide on which one; Nismo, Cusco, Kaaz; theyre probably all made in the same factory anyway!

It does concern me about the smaller drive shafts, but i suppose i could have strengthened ones made if they become a problem (i dont think they will for my application tho).

Great info, thanks again,

Shaun.

Edited September 5, 2008 by Shaun

[R31Nismoid]

Yeah mine was shimmed/clutched up for $500, its lasted a flogging for 10,000km's so far since it was done years ago.

And no signs of letting go yet

Also im using the shafts from the HR31, so probably smaller than GTR too and ive got no issues.

Rich is on the money

[NickR33]

I run the Cusco RS 2 way... daily driven and it does carry on a bit, clunking and skipping but if you adjust your driving style a bit its not a problem (coast round corners off the throttle)... I believe its a little more street friendly than the MZ as it has springs to absorb the shocks but I have never been in a car running the MZ so I will have to take Cuscos word for it... understeer and wet weather driving aren't a problem, but I run good tires and I wouldn't be so confident on yum chas... very predictable diff, makes the car heaps easier to drive than the stocker which would sometimes lock... sometimes not...

Nismo, Cusco, Kaaz... I don't think there is much difference although I have heard lots of good things about the Tomei series but don't have any first hand experience for you

[Shaun]

Yeah mine was shimmed/clutched up for $500, its lasted a flogging for 10,000km's so far since it was done years ago.

And no signs of letting go yet

Also im using the shafts from the HR31, so probably smaller than GTR too and ive got no issues.

Rich is on the money

Are you talking about your GTR diff^^^^?

Ive got some stock R33 gtr dumps if you want them. Theyre the cast things off the back of the turbine housings arent they. Just to clarify.