4.11 Rear Diff Swap discussion

[Jeff Williams]

I finally got around to opening the shipping container that holds my R32 diff this weekend. I popped off the input shaft, and compared it to the input shaft I bought from EI.

Much to my suprise, the stock G50 ABS sensor is on the input shaft, and the casing has about a 1" extension with a cast mount for the sensor, that the wheel spins inside. Then there is a seal and a metal cover that keeps dirt and moisture out.

The R32 diff has dual ABS sensors on the output shafts, and the input flange is much longer (I assume to make up for the extra length). I don't see how I am going to install the ABS sensor on the R32 casing.

In addition, the R32 casing has a larger reservoir for diff fluid, and some really nice fins on the rear cover for extra cooling. I sure hope these will fit over my HICAS steering cylinder.

I did not measure the output shaft face-to-face dimension to compare.

I wish I had a Q45 diff on the bench, to do some more detailed comparisons. I really don't want to diable my car while I figure out the best route to take.

My thoughts are that we can just order the R32 ring and pinion, and install it in the G50 diff housing. The R32 is a mechanical LSD, where the G50 is a viscous LSD, so there may be some other differences that would keep this from being possilbe.

I am going to try to find a parts car to get a transmission and diff out of locally.

Any thoughts or other experiences out there?

[Q45tech]

The 90-96 Q has two versions of differentials. The Q's with Active or TCS have dual ABS sensors on the outputs, The standard Q without these options have a single ABS sensor on the input of the diff.

[3Q Jay]

ah, been meaning to bug you about the 411. i'm surprised...Lola is not TCS? I thought most 't' models were (although i acknowledge that it's possible to have a '94 t w/o TCS). ALL 94/95 actives also have TCS, but not true for earlier years.guess you are going to have to sell me that 411.....

[Jeff Williams]

NOW I find out. Jeesh!

Does anyone know if all R32 diffs came with TCS?

I may do the swap & see if the ABS sensor can be moved to an output shaft. I bet the wiring is not long enough. I don't seem to have any kind of brackets on the diff for the ABS sensor on the output shaft.

I wonder if I could get the TCS equipped OEM cabeling and ABS sensor mouting parts?

[Q45tech]

You cannot move the ABS sensor ...................the software expects a certain number of rpm in relation to the front wheels. With an input shaft sensor the pulses will be multiplied by 3.538 rear vs front

You would need to replace the ABS ecu module and add TCS system modules.

Much easier to find an expert and pay him a fortune to properly swap and shim/lash the new gear set into the correct housing. Get a spare while you are at it.

Anyone who will do it for less than $750 plus twoway freight is not spending enough time or being precise enough.

[elwesso]

They didnt have TCS but they did have ATTESSA, or AWD.

[redmanfx]

The 90-96 Q has two versions of differentials. The Q's with Active or TCS have dual ABS sensors on the outputs, The standard Q without these options have a single ABS sensor on the input of the diff.

How about that!! And to think, I have an active 92Q. So I could do the switch of Differentials without an ABS mess!! Woohoo with a box of nuts....!

Jeff, Christmass is around the corner and I've been a very good Doobie!! I'll trade you my 92 Z32 Viscous 4:08 for the R32 Diff... Come mon, whadda ya think about that???

All this time we never knew "exactly" about the Duel ABS sensors issue, eventhough we have asked and asked, and now we know for sure. I have searched high and low and finally Q45tech comes through with the missing answer. As the Portuguese would say,."abrigado senoir"

[Jeff Williams]

I have done a few rearend gear swaps in my time. Mostly Ford and Chevrolet. The easiest is a Halibrand quick change. I have done hundreds of these at the racetrack, mostly with hot gear lube running down my arms.

Lash is lash is lash.

I wonder if the whole mechanical LSD guts will fit in my G50 casing. If so, this will be the best wy to go.

Anybody have a stock G50 diff they want to ship to me?

I may end up selling the thing after I put it in the car anyway. I may not like the added RPM at highway speeds. I am getting a set of 285/40/18 for the rear, so the speedo will be spot-on with the J30's 3.90 speedometer gear. It should raise the RPM at 80 MPH about 250 RPM with the larger tires. All I have to do then, is figure out how I can fit them in the fenders without rubbing when I lower the car with the CC springs and adjustable links.

[elwesso]

just run a little extra negative camber in the rear....

[maxnix]

All this time we never knew "exactly" about the Duel ABS sensors issue, eventhough we have asked and asked, and now we know for sure. I have searched high and low and finally Q45tech comes through with the missing answer. As the Portuguese would say,."abrigado senoir"

Well known that G50 TCS has four channel ABS with sensors on the halfshafts vs. others three channel ABS with sensor on the drive shaft.

[elwesso]

Well known that G50 TCS has four channel ABS with sensors on the halfshafts vs. others three channel ABS with sensor on the drive shaft.

LIke I said, the R32 GTR uses the 4 channel speed sensors because of the AWD system

[redmanfx]

Well known that G50 TCS has four channel ABS with sensors on the halfshafts vs. others three channel ABS with sensor on the drive shaft.

Well known to who??? Let's not think because someone wrote something that sounds Greek to people that most of us would know what you were talking about. There was no definitive yes or no this would work because of the ABS sensors. I've read many a thread that had the ABS Sensor questions in them and they WERE NOT answered to where many could understand.

LIke I said, the R32 GTR uses the 4 channel speed sensors because of the AWD system

And What?? does this mean something? Sounds Greek to me.. especially when wanting to compare to what the G50 models have. I haven't seen or heard of a comparison between the two that lets us all see what would and would not work. What Q45tech wrote made perfect sense as compared to what others have thought they said.