R34 Gtt Diff Recommendations / Would It Take Gt-r Centre?

[V28VX37]

Did search, found no clear answer:

1. Can the R34 GTT diff housing take R34 GTR diff centre/LSD? Guessing not

2. What (reasonably priced) aftermarket LSD would you recommend for mostly street/occasional circuit use?

My OEM viscous diff is starting to fade and will need an upgrade at some point. Need to retain ABS.

Based on my reading I'm guessing a 1 or 1.5 way might be the go?

From this great Trak-Life writeup: http://www.trak-life.com/basic-introduction-helical-torsen-viscous-mechanical-limited-slip-differentials-lsd/

[GTSBoy]

1 or 1.5 way Nismo or similar. The better Nismo diffs can be reconfigured a bit.

For a mostly street car I would prefer the other factory diff that came in R34s, being the helical. They're a bit like hen's teeth though.

[KiwiRS4T]

Cusco LSD can be adjusted between 1.5 and 2 way or 1 way and 1.5 if you want the choice:

http://www.cusco.co.jp/en/pdf/p27_p29.pdf

[Kinkstaah]

If you find out what centers actually DO fit a GTT I'd love to know.

I personally will be in this situation too sometime in the future, and I know Nismo have a different part number for the 1.5way vs all the other R200 diffs so I presume it must be different in some way.

[V28VX37]

If you find out what centers actually DO fit a GTT I'd love to know.

I personally will be in this situation too sometime in the future, and I know Nismo have a different part number for the 1.5way vs all the other R200 diffs so I presume it must be different in some way.

Will do, not easy to find definitive info.

Are you still running the viscous diff? Mine's still the auto one..

[Kinkstaah]

I am running the VLSD but I got SUPER lucky with the condition of the car I used as a donor car... so I expect with 400+ at the wheels it will only live so long.

So much stuff is listed as compatible with R34 but I don't believe it, due to my TC setup I 'need' the two speed sensors on the half shafts.

Like I am sure you can replace it with a R33 ABS system with R33 half shafts but what does ABS do in that scenario when it has 3 sensors instead of 4 all of a sudden?

Noone seems to know this info, and having being burned enough times I can't even trust when websites say "suitable for R34" or "Suitable for all R200 diffs" cause there's differences, like always."

The nismo part number is different for the 34 so it MUST be different which means something might be incompatible.

It's enough to drive you crazy, and the amount of 2nd hand Kaaz and Nismo's going around just makes me outright sad when you can never be sure whether it will

a) work

b) can be made to work

[GTSBoy]

The ONLY things that the diff centre has to be able to connect to are;

• Your CW&P,
• Your stab axles.

If you're dealing with ABS, then you have to use a diff centre that will happily accept your stub axles. This is actually the normal situation. It's only some of the aftermarket diffs that change the length of one side (or sometimes both) stub axles.

The main source of confusion with R34 diffs is that the few helical ones out there have different length stub axles than the viscous ones do. I would imagine that there is no difference at all between R33 and R34 viscous centres and stub axles (excepting of course the presence or absence of code rings for the ABS on the axles).

If you have a look at the Nismo normal LSD chart, it says that the R33 turbos take either the diff ending with B or BA. If you have a look at the equivalent chart for the GT Pro, it says B for some and BA for others. The R34 helical is listed there as needing the A type, but the viscous is listed as the BA type.

If you can work out what the A, B and BA stuff means, you'll be better off.

[V28VX37]

Ok just scanning through the Nismo LSD chart, it's super confusing. I would have thought the R34 R200 housing would have been the same for all cars, just with different centres?

Also it looks like for most of these have to be ordered in from Japan so you'd want to be 110% sure about getting the right part before ordering...

[GTSBoy]

It's not the housing that's different. Well not insofar as which centres go in. For example, I have an R32 housing with an S15 helical centre with the 4.11 CW&P set from an R34 viscous diff, using S15 stub axles (that are the right length for the helical centre when no other axles are) in my car.

Edited June 16, 2016 by GTSBoy

[niZmO_Man]

That would be a nice diff to drive.

[GTSBoy]

It would be, and in fact when I first put it in I was very happy with the way a helical worked compared to the shitfulness of the original viscous one. The drive feels like it comes from the outside wheel, actually driving the car around the bend. Nice.

But sadly I have a lot of CV joint slop in the S chassis driveshafts hanging off it. I don't want to spend money getting those fixed, when I would rather convert back to 5 bolt R chassis shafts.....but I am having some difficulty working out/finding 5 bolt stub axles to suit the helical centre. The only obvious ones are the ones from H diff R34s. If I could find one of those, I would have had the diff I wanted up front instead of building frankendiff!

[Missileman]

s15 helical for sale in the classifieds section atm

[Kinkstaah]

The ONLY things that the diff centre has to be able to connect to are;

• Your CW&P,
• Your stab axles.

If you're dealing with ABS, then you have to use a diff centre that will happily accept your stub axles. This is actually the normal situation. It's only some of the aftermarket diffs that change the length of one side (or sometimes both) stub axles.

The main source of confusion with R34 diffs is that the few helical ones out there have different length stub axles than the viscous ones do. I would imagine that there is no difference at all between R33 and R34 viscous centres and stub axles (excepting of course the presence or absence of code rings for the ABS on the axles).

If you have a look at the Nismo normal LSD chart, it says that the R33 turbos take either the diff ending with B or BA. If you have a look at the equivalent chart for the GT Pro, it says B for some and BA for others. The R34 helical is listed there as needing the A type, but the viscous is listed as the BA type.

If you can work out what the A, B and BA stuff means, you'll be better off.

So what this is implying is that a Nismo 1.5way that fits a R33 center will fit a R34. Presumably viscous/viscous.

Guess need to find out what that is.

My worry is that I do infact need the code rings on the stub axles, both for traction control and ABS.

I could never find out with complete confidence if the stub axles will or won't fit, but knowing that they are different at all (in the sense they HAVE abs code rings) made me think something else is probably different too, because.. just because they tend to be.

[GTSBoy]

If it were me dropping $1k+ on a centre I'd want to make damn sure the splines were the same. If it were me advising someone, I'd be a bit more blase and tell them that the housings are basically the same and the spot inside the housing where the centre sits is the same and that the stub axles they have already will provide the code rings (or not, depending on whether they're there or not!)

Let me remind you what I posted in #9 above. The helical centre does not belong in my R32 housing, nor do the stub axles. Yet they all went together. I'd be 99% confident that your code ringed stubs would happily go into an R33 centre in your housing. So long as we're talking about stuff that is all viscous originally. Helical is 99% confidence the other way!

[Kinkstaah]

99%

If you find out what centers actually DO fit a GTT I'd love to know.

100%

[dr phil]

Was yours originally helical Kinkstaah? Series 2 GTT right?

[Kinkstaah]

Tis a series 2 GTT, but as it's an auto it's a VLSD.

To me it's much more preferable than the Helical I had (but this was a S15 helical in a R34).

But it's only a matter of time really until the VLSD becomes an open diff.

[GTSBoy]

Haha! I got a wheel up in the air trying to do a turn in a driveway last night and lost all drive. Had to reef on the handbrake to make forward or rearward progress. Bloody helicals!

[V28VX37]

Ok so there's a very tempting 1.5-way R34 GTT manual centre for sale, if only I knew whether it fits auto housing... Does anyone know?

EDIT: Reading through the Nismo LSD guide it lists the following for ER34:

• Application          1.5WAY Part no.    Diff type (axle)   Final ratio   
• M/T車‘ 00/8～      38420-RS015-A    R200H              4.111
• M-A/T車‘ 00/8～  38420-RS015-BA  R200V              4.083

So there's definitely a different part number for auto, the concerning part is the 'Diff type', looks like Helical and Viscous are listed as separate. I wonder if this difference extends to the housing?

[GTSBoy]

Listen to me very carefully.

The H stands for Helical.  The V stands for Viscous.  Those two diff centres have different length stub axles.  Actually, I think it is only one of them that is different.  But anyway, if you have the stub axles that fit a helical centre you cannot fit them into a diff centre (say, the 1.5 way you're looking at) if it suits a viscous centre.  Likewise, if you have the stub axles to suit a viscous centre, you cannot fit them into a centre intended to replace a helical centre.

THAT is why there is a different part number.  The diff centres actually are different.  However, and this is important.  BOTH centres (both part numbers) will fit pretty much ANY R200 housing.  So long as you have the stub axles to go with them.  Now, if you need to obtain stubs to suit a viscous centre, that's easy.  They're lying around in any wrecker.  But if you need to obtain stubs to suit a helical, then it might take a bit more searching. The reason?  Because there are so very very few R34s out there with helical diffs.

That's right.  Most R34 manuals have a viscous diff.  If you look in the Nismo guide you'll see the earlier cars are viscous.  I should know, I bought one (hoping it was helical).

 

Short answer, As you have stated that you know your diff is viscous, then I promise you that any centre to suit an originally viscous diff will fit your car.  What I cannot promise you is that the 1.5 way centre you'd like to buy suits a viscous or a helical (well, you know, the stub axles).  But there's probably no-one except Nismo ever made a diff to replace the helical. Most people with a helical would not replace it with a mech diff anyway.