Parts required for 4:11 diff gears in an R34 GTR Vspec (A-LSD)

[djvoodoo]

I kinda have an idea, and there is some bits and pieces on the forums about it.

Looking to do the "Mines R34" diff gearing in the Getrag 6 speed. I want to retain the A-LSD in the Vspec more for the "PuRiTy" aspect of having a Vspec.

Is it a matter of more or less just using the pinion and gears into the existing rear Diff housing?

So: from an R33 or 32 GTR

Front diff pinion/gears

Rear diff pinion/gears

Rear axles/ shafts as the lenghts are different?

Is that basically it?

 

[GTSBoy]

28 minutes ago, djvoodoo said:

Rear axles/ shafts as the lenghts are different?

If you're just changing the CW&P, then nothing else in the diff changes and you don't need to consider the axles (neither the stubs or driveshafts).

I presume that it is nothing more than CW&P required at each end of the car, seeing as it's been done any number of times by others. If it was a circus, you'd hear about it being a circus.

[djvoodoo]

Nice. I was hoping that was the answer 🙂

[Jumbotron]

On 3/9/2023 at 3:38 PM, djvoodoo said:

Nice. I was hoping that was the answer 🙂

Hi did you end up doing the 4.11 gears? Is it only the front and rear CW&P that needs to be changed?

[djvoodoo]

1 hour ago, Jumbotron said:

Hi did you end up doing the 4.11 gears? Is it only the front and rear CW&P that needs to be changed?

I now have 4.11's - But, not a straight fit for the 34 Vspec. The 33/32 CW&P does not mesh inside the 34 A-LSD diff housing (different wheel to pinion thickness)

In order to retain the A-LSD, i bought a 33 Vspec rear diff.

Front is the same across 32/33/34.

 

[Jumbotron]

9 hours ago, djvoodoo said:

I now have 4.11's - But, not a straight fit for the 34 Vspec. The 33/32 CW&P does not mesh inside the 34 A-LSD diff housing (different wheel to pinion thickness)

In order to retain the A-LSD, i bought a 33 Vspec rear diff.

Front is the same across 32/33/34.

 

Thanks for confirming glad it worked out in the end. For the r33 vspec rear diff is it a direct swap, any modifications or r33 driveshafts needed? 

Also do you mind sharing where you sourced parts from? Having trouble finding front CWP or front diff from r32/33

[djvoodoo]

5 hours ago, Jumbotron said:

Thanks for confirming glad it worked out in the end. For the r33 vspec rear diff is it a direct swap, any modifications or r33 driveshafts needed? 

Also do you mind sharing where you sourced parts from? Having trouble finding front CWP or front diff from r32/33

33Vspec diff direct swap. No other modifications needed to the 34 rear end.

Initially, was hard to source the 33 vspec diff at a reasonable price. I found 1 at JustJap.

Otherwise Yahoo auctions, or go through an importer like ImportMonster etc

[Old man 32 GTR]

12 hours ago, Jumbotron said:

Also do you mind sharing where you sourced parts from? Having trouble finding front CWP or front diff from r32/33

If you just want a CWP check out neat gearbox’s in Adelaide, they make replacement CWP for GTR in a number of ratios. Not OEM and not cheap either! 
they do front and rear and they do have a good reputation, I sourced a new rear CWP and sent it to them with my front and had them shot peened, looked good when I got them back. 

[Jumbotron]

37 minutes ago, Old man 32 GTR said:

If you just want a CWP check out neat gearbox’s in Adelaide, they make replacement CWP for GTR in a number of ratios. Not OEM and not cheap either! 
they do front and rear and they do have a good reputation, I sourced a new rear CWP and sent it to them with my front and had them shot peened, looked good when I got them back. 

Yea their stuff looks very nice but man 4k for front and rear CWP 😭

[GTSBoy]

Owners of GTRs cannot complain about the cost of parts.

[djvoodoo]

2 hours ago, Old man 32 GTR said:

If you just want a CWP check out neat gearbox’s in Adelaide, they make replacement CWP for GTR in a number of ratios. Not OEM and not cheap either! 
they do front and rear and they do have a good reputation, I sourced a new rear CWP and sent it to them with my front and had them shot peened, looked good when I got them back. 

Neat don't yet make the CWP for the 34 vspec A-LSD. I know this because i was talking to them about it last year. They were looking to source a Vspec diff to get the measurements

[Heyyob22]

On 4/9/2024 at 1:43 AM, djvoodoo said:

I now have 4.11's - But, not a straight fit for the 34 Vspec. The 33/32 CW&P does not mesh inside the 34 A-LSD diff housing (different wheel to pinion thickness)

In order to retain the A-LSD, i bought a 33 Vspec rear diff.

Front is the same across 32/33/34.

 

Hey just wondering how does the car drive now with the 4.11 gears now, was there any problems driving with the R33 A-lsd? Also did you upgrade the front diff when you changed to 4.11 gears? 

[djvoodoo]

21 hours ago, Heyyob22 said:

Hey just wondering how does the car drive now with the 4.11 gears now, was there any problems driving with the R33 A-lsd? Also did you upgrade the front diff when you changed to 4.11 gears? 

It's good, but not as good as some people make it out to be on social media. Yes, you can feel the torque come in earlier, yes, it does make the car feel more lively below 4000rpm, and yes, it does feel more responsive, but it's not this 'unicorn' mod. 

Everyday driving? Below 100km/h on Australian roads, it's worth it. At 110km in 6th gear mine will sit on about 2860rpm.

Doing a Motorkhana or a small circuit? Yes, it's worth it.

Doing Texas style speed runs? Prob not.

Do you use the gears more? Yes and No. Doing 60/70km on most roads, I'm using the gears just like any other Getrag. 80km and above, you use 5th and 6th more often.

Absolutely no issues driving with the 33 A-LSD.

Didn't change the front diff, only changed the C&P wheel. Some people say to upgrade to a Quaife etc, but i've had no issue with torque steer or having it wander all over the road.

The one thing that no-one really addresses is the issue of the Speedo being out. It's either use a speedo corrector, find a 33 gearbox speed sensor, or use an aftermarket display with GPS speedo.

[Heyyob22]

15 hours ago, djvoodoo said:

It's good, but not as good as some people make it out to be on social media. Yes, you can feel the torque come in earlier, yes, it does make the car feel more lively below 4000rpm, and yes, it does feel more responsive, but it's not this 'unicorn' mod. 

Everyday driving? Below 100km/h on Australian roads, it's worth it. At 110km in 6th gear mine will sit on about 2860rpm.

Doing a Motorkhana or a small circuit? Yes, it's worth it.

Doing Texas style speed runs? Prob not.

Do you use the gears more? Yes and No. Doing 60/70km on most roads, I'm using the gears just like any other Getrag. 80km and above, you use 5th and 6th more often.

Absolutely no issues driving with the 33 A-LSD.

Didn't change the front diff, only changed the C&P wheel. Some people say to upgrade to a Quaife etc, but i've had no issue with torque steer or having it wander all over the road.

The one thing that no-one really addresses is the issue of the Speedo being out. It's either use a speedo corrector, find a 33 gearbox speed sensor, or use an aftermarket display with GPS speedo.

Thank you for the info! 
 

Did you get a 33 gearbox speed sensor to have your speedometer to work?

Does the Speedo work but not accurate? 

[GTSBoy]

A speedo corrector module has to be the simplest thing. Why anyone would consider any alternative is beyond me.

You could even knock one up yourself with an arduino in an afternoon.

[r32-25t]

Because an r33 speedo bolts straight in and doesn’t require butchering the wiring 

[GTSBoy]

Yeah, and how many of them are still lying around waiting to be used?

I think we're in a new era of Skyline modification, where you can't rely on parts from other models being available any more.

[djvoodoo]

3 hours ago, Heyyob22 said:

Thank you for the info! 
 

Did you get a 33 gearbox speed sensor to have your speedometer to work?

Does the Speedo work but not accurate? 

Speedo is out by about 12-15% I.E - If doing a road speed of 100km, the speedo is showing about 115km.

The 33 GTR speed sensor is almost impossible to come by. I was lucky enough that someone on FB marketplace was selling an entire gearbox, and i just politely asked to buy the speed sensor off him. I have not installed it yet though..

I thought about the speedo correctors, but heard some not so great things about the Jaycar unit.

Lucky for me, i use a Powertune digital dash in the 34 MFD cluster. I have the GPS unit, but the dash also has a speed offset function in which you can choose the offset percentage. So i just bang in an offset of 15% and the digital display shows the correct speed on the MFD.

[GTSBoy]

47 minutes ago, djvoodoo said:

I thought about the speedo correctors, but heard some not so great things about the Jaycar unit.

It's not ideal, by any means, but I think many of the horror stories are because of people not understanding what it is, what it does, what their VSS that they need to modify looks like and whether the Jaycar unit is applicable.

In principle, it is relatively easy to build a device to take in an AC variable (peak) voltage variable frequency signal (which is what you get from most Nissan speed senders) and just spit out a constant (peak) voltage variable frequency AC signal at a different (modified) frequency.