Trans/Rear Diff oil recommendations...
 

I think I'm going with Motul Gear 300 for the trans and rear diff fluid...good, bad? What do you guys think, anything I should be worried about?

I just changed my fluids. I used Redline MT-L and MT-90 (1:1 mix) for the MT tranny and Amsoil 75W90 synthetic gear oil for the diff. So long as you use some quality stuff you'll be fine.

Hey DJ! What a good choice of fluids! I did the same and the results have been very good. Nice smooth performance and peace of mind.... :icon17:

A very smart man already posted the following info:

Engine:

Amsoil 5W30 full synthetic (ester rated) oil

K & N oil filter (HP1008)

Filter-Mag (SS250)

Drain plug crush washer (PB147)
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Differential:

Amsoil 75W90 synthetic gear lube. You'll need two litres to do this change.



Manual transmission fluid change:

You'll need a total of four litres to do this change. You need to mix the two different fluids to get the recommended viscosity for the transmission.

Red-Line MTL (50204)
Red-Line MT90 (50304)

Amsoil hand transfer pump (G2039)

drain and fill plug washers for the manual transmission and differential. These are available at any Nissan dealership (Cost is around $3.00 each and you'll need a total of four for both changes.) Part number is 11026-4N200.

Generally speaking you shouldn't use GL-5 oils in the manual transmission (in the diff is fine). They contain pressure additives such as sulfur than can cause corrosion of the brass components, and are sometimes too slippery for proper syncro engagement. This Motul formulation might be okay, you should do some research.

Personally I was just do the diff right now (it gets nasty quickly) and do the transmission when you can get your hands on the new Redline MT-85.

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for diff it doesn't matter unless you have a clutch LSD in it(in which case use he oil provided) anything synthetic is fine gear oil is tough stuff and unless you track everyday it doesn't matter for the most part.

From what I understand most GL-5 rated gear oils are backwards compatible to a GL-4 rating. But you are right, in watching out for sulphur based additives, as they are not yellow metal (brass/copper) friendly.
One ASTM test to look for, on a gear oil, is the corrosion test with a result of 1 or less.

FYI my choice of gear oil is Shell Spirax synthetic 75W90 gear oil. I've been using it for 5 years now on all my vehicles, with great success.

Redline MT-85 GL-4 for the trans

Lubro Moly Gear Oil Syn 75w-90 GL-5 Diff
or
Richmond Gear Oil Syn 75w-140 GL-6 Diff

I did the Motul in the diff of my G35 and in cold weather it's embarrassing to drive until it warms up. After a couple of miles it quiets down, so you can't even warm up the car at first to get rid of it. My:twocents:

AMSOIL 75w90 trans fluid for the trans
AMSOIL 80w90 gear lube for the diff

I'm going with GTM's tt kit, is this something that I should change as well? or not really???

Shouldn't matter whether or not you go with forced induction. I did it way ahead of schedule (10 000 km = 6200 miles) just to get good quality synthetic fluids in there.

you mean you changed the diff and tran oil on 10k km?:confused:

I changed mine at about the same mark to put something in them better for the track. The oil from the transmission came out looking like new, the oil from the diff was dark and dirty and the drain magnet was covered in metallic sludge. So if you drive with high diff temperatures I would change the diff fluid every other oil change until it started looking better. The first change is always going to look the worst because of break in.

Thanks for the info....I will open up mine as well then :tiphat: