Well I am back again with another Diff modification this time on my R33 Gts25-T

This time I am adding extra thrust washers(shims) to the inside of the diff. This will give the Viscous Limited-Slip Differential aka VLSD characteristics of 1.5 way or 2 way diff. Google "Differential Characteristics" for an in-depth explanation of how they work for your understanding if you need it.

VLSD is decent over open-diff in relation to drifting, however, after you get use to it, it has limits. This is just another rather cheap but effective modification that can be done to all Nissan VLSD's. I'm going to go out on a limb and say that this can be done to other VLSD's from other Makers. You will need your respective thrust washer/shim.

For those who are weary about welding, this is the next best option before going with a true 1.5way/2way differential.

Tools/Material Needed

-Electrical or Air Impact
-Pry bar
-X2 14mm wrench
-14mm socket
-17mm socket
-19mm socket
-Breaker bar
-Impact Phillips
-Flat head/flat chisel
-Thrust Washer/Shim of you choice
-gasket/silicon for diff cover
-Gear oil

Supplement to help those not familiar with the terms used

Source: http://www.pirate4x4.com/articles/tech/billavista/Gear_Setup

Figure 4 Carrier nomenclature


A Housing (a.k.a. Pig, Pumpkin, Chunk, Centre Section)*
B Ring-gear (a.k.a. Crown Gear)
C Carrier (a.k.a. Diff, Differential, Case)*
D Carrier-bearing Cap
E Carrier-bearing Shims (a.k.a. Diff Bearing Shims)


1. Removing Pumpkin from Rear SubFrame

-Remove 14 mm bolts from the half shaft

-Remove 12 mm bolt holding in ABS sensor

-Remove Hose

-Remove 14 mm bolts that joins drive shaft to differential

-Place pry bar through yoke to prevent drive shaft from spinning

(note) for the r33, the space was very small unlike that of an s-chassis, I had to grind a 14mm 12 point wrench down like so in order to break the bolts lose.

-Remove 19mm Nuts holding the diff to the rear sub-frame

-Position your transmission jack under diff if available, if you're strong enough, you can support the weight with your arm

-Remove 17mm bolts on the forward section of the pumpkin, make sure you don't let it fall to the ground on your foot or something.

2. Removing Diff from Pumpkin

-Remove 14 mm bolts from pumpkin cover

-Clean Cover and apply new gasket or Silicon

-Dump Fluid out

-Tap on Half shaft to remove them, Make sure you don't mix up any portion of the diff. place your items in a fashion that will allow you reinstall everything in proper place.

-Use a pry bar in order to get the diff out. a few good pry's and it will pop out, don't let it fall to the ground!!!!!

-Be careful not to misplace or mix-match the carrier bearing shim (spacers) that are highlighted

3. Breaking Diff down

-Remove all of the 17mm bolts that joins the ring gear to the carrier

-use your impact phillips to break the two screws loose

-Use flat head or whatever you have in order to pry the lid off.

- Once you have done that, take the time to clean off all the oil fluid and sludge

-After that just apply a bit of gear oil if you would like

-get your thrust washers ready to install.

-You can use any thickness you want. there are many different ways you can go. Many other guys run 2 additional shims along with the stock one. You can swap out the stock one as i did along with the addition of two more shims giving my diff the characteristics of a 2 way diff. I am one of each size its up to you results may very.

4.Reinserting diff back into pumpkin

-Place carrier bearing shims back in proper positions

-Place bearing caps back on

- evenly lower diff back into pumpkin

-LIGHTLY tap until even.

-Insert the Long half half into diff when the time allows this will make the diff even out if it is crocked and it will ensure that the diff is indeed inline.

-apply bearing caps

-Place cover back on and tighten down in this fashion

Reverse all of your steps that you used to uninstall the Pumpkin.

After testing the differential out, it felt just like my welded differential in my 240sx but better. It is worth the 17 bucks or so a piece it cost for the thrust washers.