Silvia Club of NSW

I took the back off two diffs this arvo which I thought were an S14 viscous (3x2 bolt O/P flanges) and R33 viscous (5x1 bolt O/P flanges).

The S14 looks as I thought it would, but the R33 (if that's what it is) looks different.

Can anyone confirm what the second diff below is? The cases of both are identical.

The S14



The R33 - which LSD type?

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SR20DET 1971 Datsun Bluebird 1800SSS Coupe - 11.58 @ 122.40 MPH
Historic 1971 Datsun 1600 Wagon - L series nostalgia
Historic 1970 Datsun 1600 Sedan - Budget track racer project
Historic 1967 Datsun 1000 Wagon - A series resto

the R33 one is a 2way mechanical.

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The Engine Whisperer - fixer of things

This is true, it looks like a Nissan centre to since it's cast with some machining.
Perhaps a GTR diff, although the GTR diffs i've had apart I'm sure had steeper angles on the ramps.
Maybe different on R33s if that's the OEM GTR centre.

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1996 180sx
1990 Silvia

nice score, whatever manufacturer it is.

It should have 4.11's in it too if it's a manual r33 diff.

You can check that by reading the numbers on the crown wheel which are visible in the first pic (48/13 = 3.69? seems low geared, auto maybe?).

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meh

Thanks Dave

The upper pic (S14) is a typical 3.7 (48/13 = 3.69) 200SX diff.

The lower pic is a diff I bought for a measly $220 from ebay 2 years ago. The guy was selling it as a "viscous R33 diff" not further described. He hadn't opened it, nor did I - till now. No matter how much leverage I apply to the output flanges, I cannot force them to turn in opposite directions and it's definitely not welded.

So is it safe to say that it is a mechanical LSD of some sort?

I turned the crown wheel and found white pen markings that said 45:10 - so 4.5:1?? is this a normal R33 ratio?

I will actually count the teeth tonight.

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SR20DET 1971 Datsun Bluebird 1800SSS Coupe - 11.58 @ 122.40 MPH
Historic 1971 Datsun 1600 Wagon - L series nostalgia
Historic 1970 Datsun 1600 Sedan - Budget track racer project
Historic 1967 Datsun 1000 Wagon - A series resto

yep, it's definitely a 2 way mechanical LSD.

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The Engine Whisperer - fixer of things

yep, mech lsd.

4.5 seems pretty low, particularly for a 33gtst which typically get 4.1's

my r32 came with 4.3xx's specifically because the rb20 has no guts to run with higher gearing.

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meh

Good news dudes

Had a closer look (with a decent light this time...) - ratio is 37:9 ie 4.11:1 PERFECT!





Here are the flanges - S14 L/R on left, R33 L/R on right



Here's a better view - note the vastly different lengths and designs



So... Has anyone got any suggestions for how I could bolt the R33 diff (5x1 bolt) into my car where an S14 viscous diff (3x2 bolt) currently sits??
Do any of the mechanical R200 LSDs have 3x2 bolt flanges - ie S15?

As you can see, I have done some fairly major mods to the rear of the Datto to accomodate the S14 diff and custom (short) CV shafts, so if I can get away with a diff O/P flange swap or at most, an inner CV joint swap - then that would be great!

Here's the setup:

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SR20DET 1971 Datsun Bluebird 1800SSS Coupe - 11.58 @ 122.40 MPH
Historic 1971 Datsun 1600 Wagon - L series nostalgia
Historic 1970 Datsun 1600 Sedan - Budget track racer project
Historic 1967 Datsun 1000 Wagon - A series resto

you might be able to swap the inner CVs, which would be nice if it's possible - otherwise you might need to try to make some sort of adapter plate.

The S15 diff uses the 6 bolt flanges, but it has larger (GTR size) 31 spline shafts so you can't use those.

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The Engine Whisperer - fixer of things

Sell gtr diff and buy mech centre for the s14 diff??

Nice looking setup btw man

I'd say you could almost certainly swap the inner CV carrier/flange to a 5 bolt type.

The CV shaft is splined and the inner carrier of the CV slides over it. I can't see nissan changing it as the inner flange is the only difference between 5 and 6 bolt s13 shafts. And at 150 for a pair of 5 bolt shafts it's a pretty cheap exercise, even if it doesn't work, re assemble them and on sell.

pm nissanpower. he had a set recently.

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meh

Sounds like a plan Dave - will do. Thanks for the advice/suggestions guys.

maxboost - I really wanna use the 411 ratio for drag and circuit + maybe some drift work, so keen to hang onto the mech diff.

If the 5 and 6 bolt CV splines are the same and the swap works, I'll just leave it like that and go with the 411 mech diff full-time.

Are there any higher ratio cheap viscous 5 bolt diffs available? I occasionally drive the car long distances to shows (eg Syd - Phillip Island) so a 3.7 or higher would be desireable.

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SR20DET 1971 Datsun Bluebird 1800SSS Coupe - 11.58 @ 122.40 MPH
Historic 1971 Datsun 1600 Wagon - L series nostalgia
Historic 1970 Datsun 1600 Sedan - Budget track racer project
Historic 1967 Datsun 1000 Wagon - A series resto