Wired 24/7

iTrader: (2)

For a list of proper lubricants to use in various parts of the car, please see the top 100 questions thread
https://my350z.com/forum/2003-2009-nissan-350z/197329-the-top-100-common-questions.html

ATF != MTF (!= means does not equal)

sifuK

so is the lsd oil and manual trans oil in the same tank. sorry im a newbie to manual and lsd oil change.

Roger V

iTrader: (4)

I am pretty sure the at diff takes the same oil as the mt

Wired 24/7

iTrader: (2)

Sorry, misread post and thought you were talking about auto tranny versus manual tranny fluids.

genxnympho

iTrader: (3)

Thanks for all that info, makes things easier when crawling underneath the Z on a weekend.

Wired 24/7

iTrader: (2)

YAY just finished. Took me like 2 hrs because nobody was there to hand me tools/shop towels/etc, and I don't have a creeper.

I used ~3.75 quarts of Redline MT-90 and almost all of the ~2 quarts of Redline 75W-90 gear oil (LSD-version). You just keep pumping the fluid until it leaks out into your drip pan.

I will post my impressions soon! I am curious how it will shift since I didn't do the 1/2 and 1/2 mix of the MT-90 and MTL as some people have recommended. The specs of these two are really close, but I chose the heavier one especially since the website says MT-90 is popular for Nissans

I was *VERY* surprised at the following:
The old manual transmission fluid was VERY clean... not expected at all. Whereas the old differential fluid was blacker than coffee. I guess the diff is broken in now?

By the way, why does diff fluid smell so damn awful??

Zlayer

I called my local Nissan parts dept. and they said that the washer for the diff is not a crush washer, and that it didnt need to be replaced. Also at a local speed shop they had Redline "Shock proof" gear oil. On the back it said it exceeded 75-90, so is that OK to use?

Wired 24/7

iTrader: (2)

The service manual states to replace them, both fill plug and drain plug washers.

They may not appear to be "crush washers" but they do in fact get deformed when you install them.

I mistakenly only ordered 2 washers but I really should've put new ones on the fill plugs too.

About the shockproof, I have no idea, how about contacting redline.

n8vz

good to know. The local dealer parts counter quoted me $5 for each washer. I told him I will check online for cheaper prices

zand02max

iTrader: (22)

subscribing, I will do this when I put my Nismo Exhaust on.

Is the washers the same as the oil plug washers?

350Zenophile

iTrader: (20)

Perfomed this service yesterday on my car and a friends MX-5. Here's the breakdown:

Mileage
10,750 (85% city)

Visual condition of exisiting oils
Tranny was golden and clear with no sign of breakdown or metal shavings. Differential was muddy and magnetic plug was full of fine shavings and one large (by comparison) shaving.

Replacement Fluids
Specialty Formulations MTL-P Manual Transmission Lube
Amsoil Gear Lube SAE 75W-90

Cost
Fluids plus 8 washers with shipping=$93.11

Notes
1. Having a fellow gearhead around to make sure the bottle doesn't tip over and the suction pump tube stays submerged is very helpful.
2. Washers are not of the crush variety and looked to be in excellent condition. Good form to replace, but you'd probably be fine without.
3. Need a neck brace and a bottle of advil for soreness of previously unused neck muscles next day; either that or invest in a creeper.

Conclusion
Shifting smoother, even when cold. LSD appears to be working properly. Glad I found the SF stuff and went with the Nissan recommended weights since I make a lot of short trips and rarely get the tranny temp up. Diff was more peace of mind since it was so dirty. Overall, very happy..worth the effort and expense!

SilverII

i've changed my diff at 15K, 20K, and 30K. Only at 30K the diff fluid seems somewhat clear and with little shavings on the plug. This time I will go until 40K before the next change...

zand02max

iTrader: (22)

Is the washers the same as the oil plug washers?

zand02max

iTrader: (22)

Where can you get the washers for the diff?

Wired 24/7

iTrader: (2)

I posted it in this thread already... take another look. I gave part # and everything.

350Zenophile

iTrader: (20)

OK, I'd like to tentatively retract my smooth shifting assessment!

I guess the tranny was still warm enough when I drove it after the fluid swap to color my opinion. I drove it again this afternoon after it had a chance to sit for +48 hours and it was difficult to get into any gear until about 20 mins. into the drive. Much more so than with the stock fluid. Once warm, it shifted great again.

I may have overfilled it by 1/2 quart at most, so I might try draining some off. Any other suggestions/recommendations would be appreciated. I bought this stuff to help with cold shifting and we are heading into Fall here people!

I have an email in to the manufacturer. We'll see what he says. This stuff is supposed to be especially formulated for our trannies and low temp shifting:
http://www.specialtyformulations.com/MTL-P.htm

Wired 24/7

iTrader: (2)

I guess the question is, what makes cold shifting rough but warm shifting smooth...? Viscosity too high when cold? Hrmm..

gringott

iTrader: (17)

Sounds about right. I'm from Chicago, and back in the coldest winter days it was a bear to shift gears in a MT of any kind that I owned when cold. Just feels to me that the Z has the problem in relatively mild weather. Perhaps it is a combo of the temp and the sycros Nissan used - they have to warm up to be effective? Do the newest revisions of the trans have the same issue? I changed out my trans fluild with Amsol a month ago, at first it felt a little better, but after some driving it either is the same as before or I got used to it.

350Zenophile

iTrader: (20)

Let me also state that "cold" in Florida yesterday afternoon was about 85 degrees.

The SAE weight of the MTL-P, 75w85, is identical to the stock dino, but from a bit if reading on bobistheoilguy.com it seems these numbers are more significant:

Specialty Formulations MTL-P
K. Viscosity@100C: 11.3 cSt
K. Viscosity@40C: 73.2
Pour Point: -47 F
Specific Gravity: 0.87
Viscosity Index: 141

If I can dig up the stock dino numbers can anyone translate?

350Zenophile

iTrader: (20)

For comparison purposes:

Royal Purple Max-Gear 75w90
K. Viscosity@100C: 21 cSt
K. Viscosity@40C: 144.5 cSt
Pour Point: -40 F
Specific Gravity: N/A
Viscosity Index: N/A

Redline MTL 70w80
K. Viscosity@100C: 10.6 cSt
K. Viscosity@40C: 56.2 cSt
Pour Point: -58 F
Specific Gravity: N/A
Viscosity Index: 183

Redline MT 90 75w90
K. Viscosity@100C: 15.6 cSt
K. Viscosity@40C: 90 cSt
Pour Point: -49 F
Specific Gravity: N/A
Viscosity Index: 185

Quite a range...40C is 104F but seems to be best indicator of "cold" viscosity, if that is the indicator of performance we should be watching. We know Redline MTL is a lighter weight than the others, so is it safe to assume a lower cSt viscosity is thinner?