ATF in a Manual Transmission?

[Nathan in MI]

The Tremec 3550 I'm getting is supposed to use ATF for lube, just like the OEM T5s. I don't understand, though- ATF is not an extreme pressure lubricant, so how in the world is it going to properly lubricate the gears and synchronizers? Couldn't I run real gear lube in it instead?

Thanks, guys.

--Nathan

[DuceAnAHalf]

the tremec T-5s call for ATF Mercon-III. DO NOT USE GEAR LUBE, unless you want to destroy your tranny. there are cone shaped clutches in there (i think they are blocker rings?) gear lube eats clutch material

[Nathan in MI]

What do the clutches do? Are those the synchronizers?

[DuceAnAHalf]

What do the clutches do? Are those the synchronizers?

not sure, i just remember when we rebuilt one they had fiber clutch material on them

[Freshmeat]

The ATF enables the heat to dissipate more rapidly also.

[turbo2256b]

Gear lube for a rear end will eat brass or bronze there are some that can be used in both. There are designations that determin it like GL-3 , GL -4 as to what should be used were sorry dont remember off the top of my head.

As for use of auto trans fluid in a manual if they ere designed for it use it most now specify synthetic also. Clearances and oiling assiages are designed for th thin auto trans fluid and using the thicker gear lube could cause oil starvation the componets.

[mrltd]

Yes, the synchro/blocker rings have the clutch material on them.

Ford and quite a few other manufacturers have been using ATF in plenty of manual trannies without issues....