DANZWS6

iTrader: (67)

Looking To Change My Fluid In 6 Speed.
What Kind Of Fluid Can I Use??
Thinking Of Royale Purple Or Redline.
Thanks For The Help In Advance!
Dan

Deeavi

iTrader: (16)

I have been using Amsoil ATF in mine for two years. That is the Amsoil recommended replacement for Dexron III

02silvaZ

iTrader: (12)

royal purple synchromax, 4 qts, and you're good to go

LS1C5Vette

iTrader: (11)

Penzoil syncromesh, its gm spec, $5 a quart and works BETTER for me than RP syncromax

gold98Z28

iTrader: (7)

does this come from the gm house or local parts store?

Omec

iTrader: (2)

you can get the syncromesh from autozone i know for sure.

Delaware ss

iTrader: (2)

I use AMSOIL ATF in mine. Shifts great

99z28monster

iTrader: (3)

shouldnt use royal purple in a stock tranny. Just use any dextron III or higher fluid.

gold98Z28

iTrader: (7)

thanks, im gonna try it, they say it makes worn tranny's shift alittle better and mine is wore slap out.lol

BALLSS

Redline D4

DANZWS6

iTrader: (67)

why not royal purple in a stock trans???

99z28monster

iTrader: (3)

its bad on the paper parts. Upgraded trannys use carbon fiber so you are good if you have and upgraded transmission. The royal purple breaks down the paper.

BALLSS

paper parts in a T56????

dailydriver

Some say the same thing about the Red Line D4, but who knows?? (There have been 100+ page threads on this very topic!!)

dailydriver

The stock synchro blocker rings in a T56 are made of a cellulose fiber composite material, but most call it 'paper', since water and certain other substances in some of the available synthetic fluids can cause them to swell and malfuntion.

Deeavi

iTrader: (16)

Call and talk to the people who build these transmissions like Six Speeds, Inc. and others. Any fluid that is Dexron III compatible is what is recommended. These transmissions weren't designed to use syncromesh fluid, but people use it anyway?

There are some additives that can also help. I added some Mr. Molly to mine when I changed fluid last time. It coats the gears and parts with a thin film of molibdinum. The stuff works. Mine shifts great!

On that note, eveyone has opinions, but you really should ask the experts if you are not sure what to use.

seabirdak

I wouldn't trust anything less than Amsoil!

EdmontonSS

I've had very poor performance running any ATF in any manual (T-5's, T56, NV3500) and also with the "Redline" full synthetic MTL (only tried in a WC T-5), seemed just as bad... I've now used GM Synchromesh in every manual I've owned with fantastic results. Full synthetic ATF is by far the worst, I had someone do a full synthetic fluid service on my truck (NV3500), it was a cheap special, but the synthetic ATF is the absolute worst... I had to dump it immediately. When I first got the Camaro, I had to change the tranny fluid, came with SLP synthetic fluid package... First thing I did was dump that fluid too (wasn't quite as bad though with over 10000 miles on it already). My opinion is that the ATF is too "slippery" for the synchro's to work correctly (they require some friction to slow down the gears), I guess the faster you shift (and admittedly, the poorer at rev-matching), the more you'd notice the difference. New cars are recommending NO ATF fluid change ever, the ATF fluids have been changing over the years (better quality, more slippery) and are now no longer compatible with manual transmissions in my opinion. The "better" the quality of the ATF the worse the synchro's seem to work...

GM Synchromesh Transmission Fluid (in US 12345349 in Canada 10953465)

RevGTO

iTrader: (12)

My experience matches yours. I changed the factory fill to Mobil ATF and since then, the first couple of 1-2 and 2-3 shifts of the day are harsh. It feels like I'm beating the synchros.

JDM74

I use advance auto dexron III compatible ATF fluid. My tranny shifts like butta.