Is Mobil 1 ATF safe for T-56 Manual Trans?

[Ron-Indy]

A while back I had read that Mobil 1 ATF was not suitable for Borg Warner T-56 manual transmissions because of an incompatability with the paper lined blocker rings. Unfortunately I can now not find the source of that information.

Does anyone have any data that categorically states whether Mobil 1 ATF is acceptable for the older pre-Tremac T-56's?

Thanks much

[ March 27, 2003, 11:10 AM: Message edited by: Ron-Indy ]

 

[Patman]

My 98 Formula had a pre Tremec T56 in it and after I put in Mobil 1 ATF that is when the 1-2 shift cold grind would happen. Any rpm above 3000, if the transmission fluid was cold, it would grind a bit. This normally wasn't a problem in normal driving since I'd drive it gently till it warmed up but it presented a big problem for me at the dragstrip.

Often when I raced in cooler weather, the car would sit for an hour between rounds, so when I made my next pass, the transmission fluid was cold, and it would grind on the 1-2 shift. It never did that with the stock fluid at all, and even later on when I replaced the Mobil 1 ATF, the problem still existed, I suppose the damage had been done.

 

[jason07-1zzfe]

Personally I wouldn't use it. I'd go with RedLine MTL. Much more barrier adds. Check out Molakules UOA of MTL and his VOAs of ATF. No comparison. Yes MTL is slightly thicker but if you don't drive in arctic weather it won't be a concern and will actually protect better when running hard.
Also MTL will not shear. Most ATFs shear down even thinner than they start out at. Check out Als UOA of M1 ATF in an auto transmission for 1 example. I think the Nissan Maxima.org spreadsheet has some too. I think a manual transmission will be even harder than the auto as far as shear. If you still insist on an ATF I'd use RedLine D4, IMHO.

 

[Judd]

I also tried M1 ATF in my 2000 Firebird, I didn't like it either. Bout the same reasons, made the transmission a bit more notchy feeling.
I tried GMs Syntech and I like it. The next fill will be Redline to see what that is like.

 

[Judd]

I'm sorry folks, I messed up in my post above. It's GM Syncromesh-not Syntech. Dunno, what I was thinking.

Anyway the stuff seems to be thicker than regular Dextron. A friend who is into Fords recommended it, seems Ford T5s like the stuff too.

 

[vettenuts]

Not being familiar with this transmission, is the same as in the Vette? I changed from stock to Amsoil and still get a little "grind" during cold shifts. Has anyone tried the Redline MTL in this transmission?

 

[Patman]

Yes, the C5 uses the T56 as well. I've heard of a few people using Redline MTL with success in these transmissions.

 

[Soma07]

I used it in my T56 for a year and half with no problems, even on a very high mileage car (approaching 170k).

This past summer I switched to Honda ATF following the advice of some others who liked it. As long as the weather stays above ~65F its great, however in cold weather it shifts noticably worse than the M1 ATF.

My $.02

 

[Alex D]

I went through this whole scenario on the T56 in 1998..bottom line..M1 ATF is too slick and the synchros have a harder time matching the gear speeds before they engage, therefore you get gear clash which is really not good at all for the transmission because it sends ultra brief, high load shocks through the gears to the bearings.....kinda like pre-ignition/pinging in the combustion chamber

 

[RobZ71LM7]

If you're interested in using Redline MTL scroll down and see what LateApex has to say...
Redline MTL

 

[Alex D]

In all the trails and tribulations I had with my 98 LS1 Z28 6-speed trying to find the right transmission fluid, I figured in the end that the best fluid for the T56 is plain-jane Dexron III ATF. PERIOD......if you are worriedd about oil break down and want always fresh stuff in there, just change it once a year........everything else gave me problems when the car was hot or cold or both....in the end I went with automatic cars again and I will never look back

[ April 04, 2003, 10:33 AM: Message edited by: Alex D ]

 

[1 FMF]

that's an interesting read about redline mtl. glad I didn't go with it. I've run redline d4atf in my 99 Camaro SS 6-speed, I put that in there at 30k miles, and sold the car at 44k. The d4atf was great in the cold mornings, I could shift into 1st and 2nd. Only downfall I seemed to notice was during the summer when it was hot and the car was hot, shifting at higher rpms seemed to give some feedback, like the d4atf was too thing and the gears were banging when engaging. I never had any grind issues though nor any shifting problems, but I was reluctant to use d4atf in my 2002 SS. The 2002 has 8k miles on it so far, and has always had a problem shifting from 1st to 2nd. I drained the factory atf out last week and it was dark red

. I know good clean atf is supposed to be bright red, and GM says the T56 never needs a fluid change

After a lot of research, I decided to go with gm synchromesh, part #12345349 at $9.41/qt. I noticed an immediate difference, the transmission runs and shifts quieter, and you can feel how much thicker the synchromesh fluid is over the atf, it seems like the shifter is shifting in jello vs. water if that's a good analogy. I still have some problems getting into 2nd gear once in a while, but it is much better with the synchromesh. Maybe with a few more miles it'll get better.

My only concern with the synchromesh fluid is it's compatibility with dexron atf. I'm wondering if I should go a few thousand (or hundred) miles on the gm synchromesh, then drain and refill to ensure all the atf is out of the transmission?

Pennzoil/quaker state, and havoline have synchromesh transmission fluids equivalent to GM #12345349, they can be found where the differential gear oils are in parts stores, not where atf transmission fluids are, and is around $6/qt I think. I found this out after I bought the GM stuff