rx7ryan

i went to 2 different auto parts stores in the area and the only closest tranny fluid that they had to valvoline full synthetic 75w-90 (what the rebuilder suggested) or to Redline MT-90 (forum suggested) was Castrol Syntec full synthetic 75w-90 gear oil. The bottle says that it far surpasses conventional API GL-5 and MT-1 gear oils. Is this good enough for my freshly rebuilt tranny?

theagavejazz

iTrader: (4)

you should order some MT-90. I order from Jeg's. They ship super fast.

deadRX7Conv

Its is NOT what I would use. But, it IS good enough!
Enjoy the Castrol!

rmriggin

I have mobil synthetic 75-90 and it seems to be doing great. I just checked it a couple days ago to see how the color and level was and after 5k it still looks brand new and the level is perfect. Redline fluids are highly recommended (I run that stuff in my Diff and it is great) so I don't see why not use it. I believe factory recommendations are 80-90 for both gearbox and differential. I would go with the synthetics because they will last longer (may cost more and be a little more noisy than regular, but worth it in my opinion).

rx7ryan

i think ill use this for a few thousand then switch to redline mt-90

philiptompkins

iTrader: (4)

anyone use royal purple? I just put the non synthetic castrol in my tranny and its hard to get into first, syncros messing up maybe? anyway i think it sucks, might have something to do with my clutch adgestment though.

deadRX7Conv

You can use any gear oil you want. But, some might not be the optimum choice.

The problem with the GL5 gear oils is that some might not be synchro safe. This means that the synchro won't last as long.

I prefer the GL4 or GL4 safe gear oils.

I don't care for the Mobil1/Valvoline/Castrol fluids because they are "GL5" gear oils. They are not advertised as GL4 safe or synchrosafe.
If the GL5 gear oil is friction modified, it won't shift too easily. Friction modified gear oils are marketed as having the LSD additive in it already(like Mobil1 or Valvoline).

Some choices(GL4 or 'safe' GL5):

Redline MT90 (GL4 and my favorite)
Redline 75w90ns (GL5 but without friction modifiers)
Amsoil MTG(new GL4 from Amsoil)
Amsoil ATF
Neo 75w90hd(hard to come by)
RoyalPurple Maxgear(a little thick when cold, but might help with noisy tranny)
Motul(Motylgear and Gear300)
Castrol Syntrax
LubroMoly
Synlube MT
MaximaUSA
SpecialFormulations MT-R(new boutique oil)
Pennzoi/Coastal/Stalube/Noco/Quakerstate/Esso/Citgo have GL4's. Some autopart stores will order it. Sometimes you can find them at the bargain type stores(costco, jobber lots, wholesale warehouses....). Yellowpages oil distributors are another option.

SureShot

Then - to really make it shift great - install a short throw shift lever.

RX7_Nick

Man, free shipping but a $9.99 handling charge? I take it this stuff can't be found at the local Autozone? How much do you order to make it worth it? lol

I do need to change my oil, so the recommendation sparked my interest.

theagavejazz

iTrader: (4)

well when I order, I usually order three quarts of it and it comes out to like $29. That's only $3 S&H. I can't get it anywhere locally.

Pinfield357

Advance Auto Parts can get it but the kid behind the counter most likly wont know that. They can "Add Order" it so that it shows up on thier weekly stocking truck. But it will take atleast a week to get. It is about $8.50 a quart from them. I work there and i still buy it other places cause i can get it cheaper. Usually from a speed Shop.

Pinfield357

i also buy my redline products from www.myoilshop.com they are cheaper and will ship but i deal with them cause there warehouse is about 20 min from me so i can just go pick it up