What kind of tranny fluid does a T-5 need? And how much?

This question comes up ALOT.

Assuming your transmission still is what came in your car, you have the 1st design T-5; with brass blocking rings.

Ignore what GM says, and the crap that someone will probably post in response to your question, about how you need to know exactly what transmission you have because GM specifies gear lube in 83 & 84, ATF in 85, gear lube in 86, or whatever. Their recommendation changed several times over the years. They waffled back and forth between gear lube and ATF, even though the actual parts themselves ARE IDENTICAL IN EVERY WAY (and therefore their actual lube needs, whatever those are, are also the same...). It is as though they had some kind of internal war going on between warranty costs (which argue in favor of gear lube) and CAFE (which would favor ATF). The parts did not change until 88, when they went to the new design T-5, which has composition blocking rings; those need some kind of friction modifier, and so their lube spec was always ATF which at least makes sense unlike the early transmission.

Use synthetic gear lube such as Mobil 1. It takes about 2.5 quarts. The drain and fill plugs are both on the passenger side of the case; DO NOT take off the bolt looking thing on the driver's side!!!! If you do, you will be pulling the transmission out and disassembling it, to put the thing that falls apart when you do that, back together.

I can tell you I initially tried to use gear lube (80/90) on my '83 NWC T-5 - because my Haynes manual said so.....and it was horrible.

When cold, it was a pain to get into any gear until it warmed up, then it shifted fine. I later switched to Mobil-1 synthetic Dex III and have had no problems since. I now run a G Force T-5, (WC)and they recommended the use of Mobil-1 ATF. As a matter of fact, they insisted I use it.

- Just my experience with it.

EDIT: I never tried Mobil-1 gear lube like Sofa recommended, so maybe that'll work too. I dunno.

I bought some Castrol Dextron III/mercon. Will this be okay?

I used ATF fluid and it works great.

Also my dad cut up a piece of hose stuck then i fed it down the passenger side exhaust manifold to him and he stuck it in the transmission then I put a funnel on the end and started pouring....easy way to do things

I use Amsoil 10-30 oil with Slick 50 additive my trans shift excellent!

Ya know, I've never tried that, but I bet it works well. I don't see anything wrong with it....unless it harms composite synchos but I don't think it would. What made you think of using oil in the first place?

I have tried just about every fluid available Synthetic Dexron, synthetic gear oil, different oil weights and all the regular oils with only fair results. I use Amsoil in all my vehicles so I decided to try some 10-30 and that works perfect, A friend of mine had a T-50 that was noisy so he added some PTFE additive and cured the noise so I combined the 2 lubes and now have a trans that shifts excellent even over 6K RPM.

what do you all think of penzoil synchromesh for gm vehicles?

i have a few friends that have used it in their 5spd cars (imports) and it has solved grinding and hard shifting problems.

Royal Purple Max Gear is the shiat.

so anyone ever use it...its developed specifically for gm vehicles???

I use the GM synchromesh oil in my TKO.

http://www.lastofthebreed.com/Servic...6FAQexplan.htm

according to that it is safe for the t56

Sorry to bring this thread back to life, but Fast Tony,
how much of each - Amsoil and Slik 50 do you mix and then pour in?
-Andrew