I have fitted an R32 GTR LSD to my car so thought I would share some details of my install. It's a fairly straight forward swap and a good opportunity to upgrade over standard R200/R230 Viscous LSD. Notes: My car is a '90 Z32 TT, converted from NA, so it already had the standard NA subframe in it with R200 VLSD. If your car is a TT with the TT subframe and R230 VLSD then this mod will be slightly different for you. You will need to swap to an NA subframe and your prop shaft may need modifications. My car does not have ABS so I can't confirm the ABS tone wheels on the diff are the same as Z32 as my NA diff does not have tone wheels on it. For those of you with ABS it is worth checking this prior to attempting the mod. GTR FDR is 4.11:1, Z32 NA FDR is 4.08:1, I don't really notice any difference in terms of RPM vs speed as the FDR difference is negligible. This FDR suits me as I mainly use the car for track work. Why do this? Increased strength in the drive line. If you are running the standard NA rear end then you are running the R200 VLSD with 5 bolt output and 5 bolt half shafts, this is essentially the same as R32/R33 GTST. With sticky tyres, high torque launch and a bit of axle tramp, there is a good chance you will break the half shaft. See here for an example, note semi slicks in the picture: http://www.aus300zx.com/forum/showpost.php?p=1316839&postcount=4 The Z32 TT and R32/33/34 GTR use the 6 bolt half shafts which are thicker and stronger than the 5 bolt halfshafts. The wheel bearing is also larger to accommodate the larger spline end in the wheel hub. The NA cradle swap into a TT saves approx 30kg. This upgrade offers the weight reduction of NA rear end, 4.11 FDR, with the strength of the 6 bolt TT shafts and the big one... GTR uses a clutch type LSD centre. Z32 (NA and TT) are Viscous LSD. What you need: R32 GTR diff not V Spec 2 active diff. I believe R33 GTR (non V Spec) may be the same however it does not have the same finned cover the R32 GTR diff does. You don't want the active diff (R32 Vspec 2, R33 Vspec) as it uses computers and hydraulics to control a pump which operates the locking centre in the diff. Z32 TT half shafts (6 bolt). Note that S13 also uses 6 bolt shafts but in a 3x2 bolt pattern. These are weaker than Z32 NA and TT shafts. Make sure you're getting Z32 TT shafts. Z32 TT wheel bearings Z32 TT wheel hubs Z32 TT wheel bearing seals - these are larger than NA Z32 Spacer plates and longer bolts to join R32 GTR diff to Z32 TT half shafts. This is needed as although Z32 TT and R32 GTR diffs have the same output flange bolt pattern, the Z32 TT R230 diff is wider than the R32 GTR R200. You fill the gap with spacer plates. I have the drawings for these if you need them. They can be made in the lathe quite easily. The TT wheel bearing seals that press into the knuckles. How to do it (use service manual or tech section for procedures and torques) -Remove NA diff -Remove NA half shafts -Remove NA hubs and bearings Prep R32 GTR Diff: The R32 GTR diff bolts straight in except you will need to swap the pinion flange between the Z32 NA diff and R32 GTR diff. This is required because the R32 GTR diff uses a CV joint on the prop shaft (as per Z32 TT) whereas the Z32 NA uses a uni joint. This is not quite a straight forward swap as setting the torque on the pinion flange nut affects the preload on the crush tube and bearing in the diff. I had a workshop set up the diff for me as I also had a Nismo clutch disk kit put into the CLSD centre. This makes the diff a bit more aggressive than a standard GTR CLSD. It's also a good time to change the rubber mounting bushings in the nose of the diff and put in some good diff oil. If you don't swap the R32 GTR pinion flange then you will have to put a CV joint on your prop shaft or make some sort of 4-bolt --> 6 bolt adaptor for the pinion flange. Note: I don't have enough measurements on the Z32 TT propshaft to determine if it is suitable length for R200 GTR diff. Prep the knuckles: Swap the Z32 NA wheel bearing seals to Z32 TT wheel bearings seals. Pretty straight forward, they just push out/in. Fit the Z32 TT wheel bearings and hubs - same bolting pattern on the knuckle as the Z32 NA wheel bearings. Torques as per FSM. Torque down the handbrake anchor and refit the handbrake assembly, rotors, calipers etc. Fit the Z32 TT half shafts - note that they are different lengths, the longer one is fitted on the RHS in this install. Fit R32 GTR diff to vehicle. The mounting points are the same as the Z32 NA diff so just use the FSM for assembly guide and torques. Your standard NA propshaft will work with the R32 GTR diff if you have swapped to the Z32 pinion flange. Torques as per FSM. If you are using a TT propshaft with GTR CV pinion flange on the diff then you might need a spacer between the propshaft and R32 GTR pinion flange (CV). I'm not sure on the physical size difference between R230 with CV and R200 with CV. Fit the spacers between the R32 GTR diff and the Z32 TT half shafts and torque the bolts between the diff output flanges and half shaft. I upped the torque to account for the spacer plate between the diff and half shaft. They are 34-44 Nm from the FSM. Finish the rest of the install as per the FSM. Don't forget to torque the half shafts to the hubs as per the FSM and install the locking pins Hope this helps.
i will be doing this as well soon , as we spoke about when you were at my house , i would love to take the car for a spin and see how it feel . great work sandeep , looks great , is it really 30kg tt subframe vs NA subframe ? with diff or with out ?, i assume with diff , thats alot of kilocycles, :zlove::zlove::zlove:
If you were doing it on the cheap with used parts: R32 GTR diff - $400 from a wrecker. I scored a bargain here because they generally go for $500+. Mine was in really good condition too, the workshop said based on the bearing, gear and seal wear it was only about 10% worn. Z32 TT halfshafts - $100 from a wrecker or someone parting out a car on the forums Z32 TT bearings and hubs - $50 from a wrecker Z32 TT bearing seals - $12.50 each new from CZP Spacer plates free if you make them or about $100 to get them machined at a shop I bought new hubs and bearings from CZP as I didn't really want to risk using a used bearing on my car. The labour for the diff was optional as I wanted to do the clutch pack upgrades and get it all set up properly by Racepace. They do a few tricks to the to clutch plates during the install to set them up for track work.
Nice writeup Sandeep, are you able to put this in a .doc or .pdf? If yes I can ask Pex to add to tech.
Hi Alex. for sure, you can have a drive after I run in the clutch plates and change the fluid. UAS did a weight comparison between R230 and R200 and they are about 16kg heavier in the diff itself. Blackbeast mentioned that once you swap to full NA rear end on a TT and delete HICAS you'll lose about 30kg overall.
Sure. I just clicked the view single post button in top RH corner of the post (#1) and can print the first post as a PDF. Will wait a bit to see if there are any more questions.
Then you've already saved the weight, Alex. Yeah I agree. When people say they saves weight going to an NA rear subframe it actually has little to do with the subframe itself...
Here's a diagram i made up last night which may be of use to add to later on ...I was getting confused between Prop shaft and Driveshaft and mating flanges, but once i had it drawn i understood.
Looks like this diff swap just got even easier. Gktech make off the shelf spacers in 10mm and 15mm for 6x1 bolt half shafts. https://gktech.com/index.php/6x1-10mm-axle-spacer-pair.html?SID=631efee5be5ccebef6d59e8d9e0c9c19 Note: I haven't tried their spacers but the price seems good. Thanks to Mijake for the heads up. My diff has been fitted for close to a year now and all is going well. The clutch LSD is a noticeable improvement over the standard viscous unit.
