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:

I ran Motul Gear 300 and PA90 in the rear diff in my STi and it was great. I've been thinking of changing to Amsoil... but I've always had good experience with Motul stuff.

I just ordered the redline 85 for the man trans since I just hit over 30k. I was wondering and never thought about the rear diff. When should that be changed and what's the concensus on what is the best to use??

Has anyone used Mobil 1 syntetic gear oils on their diff and or Manual trans? If so any comments (good or bad) thanks.

Is it true the AT transmission fluid never needs replacing according to Nissan? Also, what is the maintenance schedule for the diff. oil, or is that a "lifetime" oil too?

Thanks...

I think that depends mostly on how you drive. I would flush the AT fluid and replace somewhere between 60k and 100k depending, the flush technique is described in the service manual. I would only refill with Nissan ATF at this point. You need 2x the fluid for the flush.

For the rear-end, the viscous unit is sealed so you can only really change the fluid for the sake of the pinion and drive gears. It's not a bad idea to change it once after an extended break in, 5-10k, there is a fair bit of metallic debris on the drain magnet at this interval.

So the tranny fluid and rear diff doesn't have to be changed until 60?-100k miles? I would go Royal Purple just because they say I'll gain some horses and I saw it on Gearz and the guy gained like 10hp + on his dyno. Is there a how to on the tranny and diff fluid changes with pics???

The Nissan recommended maintenance schedule is as follows:

Oil and filter - every 3750 miles
Diff oil - every 30,000 miles
ATF fluid - every 30,000 miles
MT fluid - every 30,000 miles
Coolant flush - every 30,000 miles
Replace drive belts - every 30,000 miles
Spark plugs - 105,000 miles

Obviously you have to use some common sense. If you drive your car hard constantly then you are going to have to shorten the intervals especially the oils. If you drive like an old lady with 90% highway then you can double the intervals (except spark plugs), and according to Nissan not have to change the fluid in the AT at all.

I can't recommend Royal Purple in the transmission and diff, yes it has shown to increase power delivery by a small amount but it has also shown to increase wear at the same time. It is popular with racers as they don't care about wear, most of their parts fail due to abuse before wear is even an issue. Just remember that what you saw on TV was probably paid to be there.

Basically a repost but different people look at different threads so I wanted to throw it out there.

We have been using Redline for some time at the shop and the fluids we use for the following applications are....
We use the normal 75W90 for the differential. You can find it on our site HERE.
We have recently begun using Redline's MT-85 for transmission fluid. Redline specifically lists this fluid for use in the 370Z. You can see it on their site HERE. I really appreciate a customer and forum member for pointing this fluid out to us. The MT-85 fluid can be found on our site HERE.

Finally you can find the metal washers for the drain plugs on our site HERE.


This is what we have found works well in the majority of 370Z applications.

Bringing the thread back! Just order Redline MT85 and 75w90 diff fluid from Z1. Going to use Motul synthetic in the engine, I've been using Motul 300v Power Racing for the past 2 oil changes and when teamed up with an oil cooler its been great.

Bringing the thread back one more time lol

I have a 2014 370 with the sport/touring package.
It’s time for a diff fluid change and I want to try motul.
I have a LSD and was told I needed the motul 300 LS 75w-140 but when I ran my VIN it said Motul 300 75w-90.
Question is, what will get affected or is it fine to just use the motul 300

Thanks in Advance!

Factory Viscous LSD? If so, either will work. If you are tracking the car, 75w140 is for you.

What is your observed improvement/difference in your 1:1 mix vs. MT-85 alone, as called for by Redline?

ZZ

Yea straight from factory. And I wish I could track it, no time 😭
Thank you though for confirming it!