Wanting To Change Gearbox/diff Oils - Advice

[Booki]

Hey everyone,

I have read the stickies that are posted up about which oils people use for there gearbox/diff's and transfer cases.

After reading the 6 pages of opinion's, to be honest i am still confused on what exactly to put in my R33 GTR, and where to buy them, Supercheap?

I am wanting to drop the gearbox/diff oils this weekend. Is there any other oils i should consider while the car is up? (Already done engine oil and filter)

Some people have said they love and use the redline lightweight shockproof stuff, others say don't use it as it has a changed formula.

So sorry in advance for the common question, but I am just balls to the wall confused about what oils to put in the GTR!

[tricstar]

mate, all your gonna get is lot opinions ( I use this, its the best etc ), depends a lot on what you use the car for ?

I've spoken at length to a guy that builds and rebuilds these box for a living, and he basically said this.. if you are just driving around the streets with abit of hard driving here and there, then by all means pay the extra and get the expensive stuff and only change once a year or there abouts..or if your doing a fair bit of track and sprints then any oil the right weight will do the job, just change it after every couple of events..thats what my gearbox guy says anyway.

and he said make sure you don't go too thick in the gearbox, something around 75-80..

It's going to be pretty much the same with the diffs. just make sure you get the right weight .

[turboedsloth]

If you're not fussed about brands, either Castrol VMX-M which is a 75-85, or Penrite Sin manual Trans which is also 75-85. I use both these and don't have any problems in the gearbox.

Diff wise, penrite reccomend 80-90 oil front and rear

[Booki]

I am using the car as my daily for the moment.

Won't be tracking the car. At least not in the near future anyway.

So pretty much get something that is within the manufactures weight recommendation's is what i am after?

[Booki]

Also the workshop manual I have for the GTR has nothing about the Diffs or Gearbox's in it. Can somebody point me in the right direction on where to grab a manual stating the weight required and a guide? Mainly for Torque specs

[tricstar]

mate your changing the oil not the clutch? Torque specs??

[Moodles2]

If you want cheap, Castrol VMX (mineral), if you want something better then the Castrol synthetic range

If you want the best: If the box sometimes crunches at track conditions then, Redline Shockproof. If it doesn't crunch then Motul Gear 300 or Redline MT-90.

In the end the gearbox and diff require a gear oil that meets the GL-4 specification, GL-5 is backwards compatible so any GL-5 fluid at the server manual recommended SAE weight (75w90, 80w90, 75w85 etc). you can use 80w140's for example (shockproof lightweight is an example) but they are more suited for track conditions and can make your LSD lock up in undesirable situations like driving the streets around roundabouts or parking your car.

So as long as you choose a GL-4/GL-5 oil at the correct weight you should be right. I've read people who had shockproof in their gearbox and got scared about all the stories going around about destroying their synchros only to put Castrol in and pretty much immediately dump the Castrol and put the old shockproof back in.

[central coast person]

Well if its a GTR first off so dont stick 80w-90 in your rear diff, it will be fine in your front diff but that oil does not suit the rear diff because the LSD is setup with hypoid gears so normal oil will just squeeze out the teeth on the crown and pinion because of the pressure applied with the way the diff is setup. You need 80W-140 which is made for hypoid gear types and LSD's so you dont run it dry.

From factory

Front diff is: 80w-90

Rear diff is: 80w-140

Gearbox: 75w-80 (just use a redline lightweight shockproof as the box is getting old)

Transfercase: Nissan Matic-D

[Moodles2]

As what was said above, just make sure a LSD oil is put in the rear diff as it is a hypoid diff not a viscous diff (found on RB25DET equipped cars). You can put LSD oil in non-LSD's that's no problem if you plan on using the same fluid front and back.

[R31Nismoid]

From the Nismo manual:

When the L.S.D. is installed, a chattering sound (a clanging or clanking sound produced by heavy pieces of metal striking together) is heard. This is a sound produced when the L.S.D. is working and there is no problem with performance.

Use the L.S.D. oil of NISMO make (GT-R racing oil L.S.D. 80W-90) or the Nissan genuine differential gear oil (Differential Gear Oil Hypoid L.S.D. 80W-90/140).

If oils other than specified are used, an excessive chattering sound may be produced.

I've got LSX-90 in mine, as have many others, no issues and it's cheap for 4L (2 oil swaps out of a bottle)

LSX-90 is ok for Hypoid diff types: https://www.ils.co.nz/B1WebTools/assets/downloads/SKU%20TDS/4100637.pdf

If you get chattering and want to remove it, just add a bottle (it's small) of the Penrite friction modifier

[Booki]

Well if its a GTR first off so dont stick 80w-90 in your rear diff, it will be fine in your front diff but that oil does not suit the rear diff because the LSD is setup with hypoid gears so normal oil will just squeeze out the teeth on the crown and pinion because of the pressure applied with the way the diff is setup. You need 80W-140 which is made for hypoid gear types and LSD's so you dont run it dry.

From factory

Front diff is: 80w-90

Rear diff is: 80w-140

Gearbox: 75w-80 (just use a redline lightweight shockproof as the box is getting old)

Transfercase: Nissan Matic-D

It is a GTR, and from my knowledge its still all factory. No mods. So stock box.

What is nissans service intervals for the diff's, gearbox and transfer case oils?

Guess i will be shelling out the big bux for the redline shockproof...eeep

Edited May 11, 2012 by Booki

[Booki]

mate your changing the oil not the clutch? Torque specs??

...Fair point ha ha, I'm just a REAL fussy owner.

[KiwiRS4T]

...Fair point ha ha, I'm just a REAL fussy owner.

g/box filler and drain plug 25 -34 Nm or 18 -25 ft lb

diff 59 - 98 Nm or 43 - 72 ft lb

(from the R32 GTR manual)

[Booki]

Ah thanks!!! Little too late though, Already done and dusted...

Took some pics too so will post up a bit of a DIY/Thoughts.

I ended up just throwing in Castrol VMX-M.

Shifts pretty much the same as it did before, going into first is smoother thats all i noticed.

The old oil smelt like ass and was black as, and the magnetic sump was full of filings so i think it was still worth while to change it out.

[Booki]

So the gearbox oil change went on without a hitch.

I bought a little pump from supercheap auto, There were a few pumps around $10, but i opted to go for the $20 pump.

I highly recommend it, didn't take long at all to pump the 4L of Castrol VMX-M into the gearbox.

For some reason the last person who changed the gearbox oil had put some gasket goop around the sump, i opted not to this time. So far it hasn't leaked. Is this common/best practice to do so for diff, gearbox, transfer case sumps? First time i have ever seen it.

Also for the record, the sump/fill plug sizes are 1/2". I used a 1/2" ratched to do them up. Used a breaker bar to get them off.

What do you guys put in the Diff's (Front and rear) and transfer case?

Also found out i have a "Ganador" exhaust. Thoughts? Any good?

Edited May 14, 2012 by Booki