Manual Transmission Fluid

[Alero_1986]

I am changing my transmission fluid along with other repairs currently on the go. Wondering what others with the F23 are running.

GM recommends Dextron III Automatic Transmission Fluid for the Getrag F23 transaxle. However, a few members of J Body Ontario have had pleasant experiences with MTF synchromesh.

Originally Posted by spddmon

I have just switch trans fluid to Amsoil MTF Syncromesh, and it is hands down the best fluid I have used. Whether hot or cold it shifts the best.

For comparison I have also used:

Regular dino ATF was too thick cold and too thin hot.

Mobil 1 syn ATF (for about 20K) and found it way to thin. Very notchy, hard to get into reverse and I had to double clutch to get into first when downshifting from second.

Royal Purple Syncromax was a great improvement from the Mobil 1. Smoother and easier to get into gears. I accidently spilled some when an axle popped out doing a ball joint, and I was surprised to notice that it had significantly darken over the 15K it was in the tranny. I mean it was black, all the other fluids (regular ATF, Mobil 1 ATF, and Amsoil ATF) came out looking brand new even if they had more miles on them.

Amsoil syn ATF was the only thing I could find on a Sunday afternoon after I spilled the Royal Purple. This fluid worked ok but alot of the Mobil 1 characteristics return. I just find syn ATF is just to thin.

I realize that GM recommends ATF for the Getrag but there is also a bulletin to use syn Syncromesh in the Getrag if you experience trans rattle. Plus Amsoil MTF syncromesh viscosity is only slightly thicker than ATF but nowhere near as thick as gear lube (i.e. Redline MTF). For reference RP viscosity is almost the exact same as ATF. Amsoils is also a GL4 lube unlike B&M which is a GL5 which can cause excellerated wear of brass components.

[Alero_1986]

Can anyone see any potential ramifications of running the synchromesh? or should I just stick with a Dextron III compatible synthetic ATF

[Midgear]

Dextron III Automatic Transmission Fluid for a manual transmission?

[Alero_1986]

Originally Posted by Midgear

Dextron III Automatic Transmission Fluid for a manual transmission?

You learn something new everyday, huh?

Yup, Owners manual even says so.

[Redog]

DO NOT CHANGE THE TRANNY FLIUD ON A MANUAL TRANSMISSION!!

The only time you change the fliud on a manual, is when there is a rebuild, manual tranny fliud is more like a lube than fliud

[Midgear]

^ that's what I was thinking.. manual fluid is more of a lube.. some people refer to it as gear oil rather than tranny fluid

[Alero_1986]

Originally Posted by Redog

DO NOT CHANGE THE TRANNY FLIUD ON A MANUAL TRANSMISSION!!

The only time you change the fliud on a manual, is when there is a rebuild, manual tranny fliud is more like a lube than fliud

thanks for the advice, but I'll let you do your own research

[Redog]

^^ Have fun

[Fast Eddie]

Originally Posted by Redog

DO NOT CHANGE THE TRANNY FLIUD ON A MANUAL TRANSMISSION!!

The only time you change the fliud on a manual, is when there is a rebuild, manual tranny fliud is more like a lube than fliud

Funny, the guys at GM told me to change it every 25-30K miles. I know they don't know everything but the MT has all the holes needed to change the fluid as easy as the oil. I've changed mine every 25-30 miles for years now and had no problems.

For the record, I use redline D4, ATF

[spyhunter]

Originally Posted by Alero_1986

Can anyone see any potential ramifications of running the synchromesh? or should I just stick with a Dextron III compatible synthetic ATF

either that or that or Redline equivalent to synchromesh

[jamcllw]

Dude your tranny is as good as gone if you put ATF >>>AUTOMATIC Transmission Fluid in there.

Unless your having trouble with is I'd leave it alone.

ATF was proven long ago to not have sufficient shear strength for use in a manual transmission. That's why the transmission manufacturers switched away from it, though it used to be specified during a time transmission manufacturers were trying to standardize on just one lubricant.

[spyhunter]

Originally Posted by jamcllw

Dude your tranny is as good as gone if you put ATF >>>AUTOMATIC Transmission Fluid in there.

Unless your having trouble with is I'd leave it alone.

ATF was proven long ago to not have sufficient shear strength for use in a manual transmission. That's why the transmission manufacturers switched away from it, though it used to be specified during a time transmission manufacturers were trying to standardize on just one lubricant.

FOR THE RECORD! ATF comes in getrag F23 trannies on both n-body and j-body from the factory.

When changing the fluid for one reason or another, switching to the saturn synchromesh is a perfectly viable option. There was even a minor bulletin about consumers complaining about a noise in the tranny, the solution was to switch to synchromesh.

ADDITIONALLY. Using Redline MTF is fine as well on the Getrag tranny.

Why? Because I've been there, searched, talked, inquired, reaffirmed, backtracked, looked backwards, spelt shit backwards.

[guiguilandry]

Originally Posted by spyhunter

FOR THE RECORD! ATF comes in getrag F23 trannies on both n-body and j-body from the factory.

When changing the fluid for one reason or another, switching to the saturn synchromesh is a perfectly viable option. There was even a minor bulletin about consumers complaining about a noise in the tranny, the solution was to switch to synchromesh.


Why? Because I've been there, searched, talked, inquired, reaffirmed, backtracked, looked backwards, spelt shit backwards.

Yep That's the good thing to do, Saturn Fluid FTW. I did it as well and I worked at a GM Dealership and checked for that bulletin about noise... and also asked to the transmission guy in the place. It helped to reduce the noise alot

[Alero_1986]

Thanks for the opinions guys. I think I'll go with the Amsoil synchromesh as I had originally thought. I may also check a price on the Saturn fluid for comparison.

[kwhauck]

FTW.....

[Cliff8928]

Is that the same Synchromesh fluid that came in the 282s from way back when? (#12345349)

There's also a Friction Modified Synchromesh (#12377916)

From what i gather, the Saturn fluid used to be a completely different part number.

Also, You can use Dexron III for your F23, but under NO circumstances use Dexron VI. GM *SPECIFICALLY* states this and now sells "Manual transmission fluid" which is just Dexron III just for the manuals that require it.

I know the Redline MTL was praised in the 282. However the original synchromesh is all the hype with the honda, acura, subaru, mitsubishi, etc.. owners.

[Nate's Alero]

lol, i was just about to ask this, saturn is a bit low on manual fluid.....thanks again, i was not going to put ATF in my car because of the fact that its not an AT!!

[spyhunter]

Originally Posted by Nate's Alero

lol, i was just about to ask this, saturn is a bit low on manual fluid.....thanks again, i was not going to put ATF in my car because of the fact that its not an AT!!

but ATF works.

[Alero_1986]

Decided to go with the Amsoil Synchromesh. Got everything back together yesterday.

Wow, what a difference! this is probably the best investment I have made yet!. Shifts are incredibly smooth!

I usually cannot tell much change when swapping between brands for "proclaimed gains", so I wasn't expecting much change with the new fluid. This was not the case.

I highly recommend this fluid, or similar synthetic synchromesh fluid, to anyone who is still running the original Dextron III ATF in their F23's.

[Cliff8928]

I might have to do that some time. Mine shifts a little rough in the cold weather. It probably has Dexron III (there is no "T" in Dexron). The dealer replaced an axle seal not too long ago on it.