ahmedsaleh

i read a little thru the search but didnt find a decent answer..

i have a w58 and stock 92 sc300 5 speed diff.

i make about 500wheel hp and beat the **** out of my car.
whats the best fluid i can run in it.

i just want one simple answer. the best protection from wear for these parts.

thankyou

rwdanthony

iTrader: (53)

best protection would be going back to atleast 400 hp and not beat the **** out of your w58

you should look for your r154 already if you want to keep those numbers.

but your simple answer would be royal purple...

ahmedsaleh

at 400hp id get raped by everyone in cleveland. ill i do is highway pulls so beating the **** out of it was sayin too much..

what wieght for trans and the diff.

rwdanthony

iTrader: (53)

trust me, go to 400, do a r154 tranny and sc400 diff swap. youll be faster then being at 500 hp and what ever torque numbers.

80w-90 tranny about 2.5 qts some guys put 3 qts

you can use the same weight for the diff. 1.43 qts

ahmedsaleh

r154 trans will need too much right now since i just got a new clutch for the w58.
r154 id need clutch flywheel drivshaft slave cylinder and god knows what else.

rwdanthony

iTrader: (53)

well lets not derail the thread

GL on your oil service!

ahmedsaleh

you dont think i should go thinker or can i mix the it. some 90-140 with the 80-90

lemmiewink

I strongly suggest redline mt-90 for your transmission. This fluid is a GL-4 class 75w-90 which has the right "coefficient of friction" needed for the w58-r154 transmissions. It is thin enough on colder days that it will help prevent grinds while waiting for it to warm up, yet it is thick enough at operating temperature to protect your gears and brass.

At least stay away from gm synchromesh, rp synchro max because both are too thin at operating temperature which will promote wear.

Also stay away from any transmission fluids that have friction modifiers. These are GL-5 fluids with friction additives that are designed for LSDs. This will cause very hard shifts. It doesn't grind, but it takes a bear to push it into gear.

Obviously for your lsd I would suggest a GL-5 fluid with friction additives. As for the wieght, I'm not really as experienced on that so I'll keep my mouth shut.

I've used royal purple synchromax and max gear, GM synchromesh, and redline mt-90. All but mt-90 would shift like crap either all the time or upon start up.

ahmedsaleh

thanks for the info

AD_SC3

iTrader: (1)

Damn 500hp? Your tranny loves you

ahmedsaleh

im at 470 right now with 440cc injectors gettin 550cc and a 50shot of spray will see how that goes..

ahmedsaleh

if it does ill sell put another one in and sell it.ive went 10s at 130mph in my mustang and didnt break anything in 3 years and had half the money in it i do the lexus.

Blizzy

iTrader: (-1)

I pretty much agree with this assessment.

The transmission would prefer a GL-4 that would still have the thickness of a w90 fluid. The differential would prefer a GL-5...with friction modifiers (assuming your have an LSD).

Some of the most ruggedly designed gear oil out there is from Redline in their "Shockproof" line. This stuff was designed for the sole purpose of making its way into racing vehicles. The Superlight shockproof is designed to decrease hydrodynamic drag for dyno queens to squeak out a few extra horse. The Lightweight shockproof was designed for most racing applications, and the Heavy shockproof was designed for heavy-duty racing conditions. The Heavy shockproof actually contains microscopic solid particles to help increase the oil's coating ability to maximize cushioning. Some of the MK3 Supra guys have had warning signs of their first gear thrust washer going when the transmission begins to throw itself out of 1st gear, they switch to the Heavy shockproof, and the problem never resurfaced.

That being said, you could have gear oil made out of gold and it will not help you prolong the life of your transmission significantly if you are running a 500hp through a W58. In the meantime, I would suggest buying some quality synthetic 75w90 (Royal Purple, Redline, Amsoil, Mobil, etc) while investing some time to research the R154 swap that should be in your future.

dejacky

iTrader: (2)

how about Redline ShockProff transmission oil?

ahmedsaleh

thats what i put in my wrx when i had it. wrx guys like to put 1 light wieght shockproof mixed with there mt90.