Sir.William

iTrader: (3)

So I am putting my winter build back together and I am not sure what gear oil's I should use in my tran's and rear. I am looking for some suggestion's. It's a '87 TII. Thanks in advance for any replies.

Evil Aviator

Synthetic gear oil is good for extreme temperature (hot or cold), and it usually makes the shifting less notchy and tends to cut down on gear noise. I use Red Line Oil MT-90 in the transmission and 75W-90 GL-5 in the differential. You can also use other brands, such as Royal Purple, Amsoil, NEO, Idemitsu, Motul, etc. Just make sure you get something that is rated for street vehicles, not only race cars. The factory service manual in the FAQ lists the quantity that you will need. If you have trouble finding synthetic gear oil locally, you can order it from online dealers like Racer Parts Wholesale:
http://www.racerpartswholesale.com/

Cordt

yeah just use the proper weight recommended on the sticker under the hood, any kind of synthetic will do. simply fill it up until it starts leaking out the fill hole (on level ground) and you're good to go.

thejallenator

iTrader: (14)

and since you have a tii make sure that the oild for the rear end has the lsd additive

Sir.William

iTrader: (3)

Thanks guys. The rear end was my main concern is there any gear oils already for LSD or do I have to mix it?

Cordt

yeah there are oils that are formulated for LSD but if you just buy the additive and add it separately you'll have a much larger selection to choose from

Sir.William

iTrader: (3)

Alright what about this Kaaz Gear Oil on mazdatrix?


http://mazdatrix.com/q-supply.htm

Evil Aviator

One of the reasons why I like Red Line 75W90 is that it is already set up for LSD use, so there is no need to spend more money and more time on additives. Some of the serious racers like to use non-LSD oil like Red Line 75W90NS and then add the LSD friction modifier in a ratio to their own liking. Personally, I would rather not go through the hassle.

It is not synthetic, and it is super expensive.

Sir.William

iTrader: (3)

Thank you Evil Aviator I looked into the RedLine oil's and it looks good. If it is good enough for your 20b swap its good enough for me.

Evil Aviator

LOL, far better rotary-powered race cars have used Red Line for decades. The only oil with a better rotary race record is Idemitsu, and I am too lazy to mix in the LSD additive so I just use Red Line.

I consider the Group V (polyol ester) base stocks to be the best. The Group IV (PAO) based oils are great, too, but given similar pricing I would rather choose one using Group V base stock (which is usually blended with Group IV stock). As far as I know, here is a breakdown:
Group V: Red Line, Idemitsu, Total/Elf, Motul, Neo, Silkolene
Group IV: Amsoil, Royal Purple
Group III: Fake synthetics like Castrol Syntec and the current Mobil 1