Muncie trans

[reborn55]

What is the recommended gear lube for fine splined Muncie 4 speed. Going to change grease before road trip to Hot Rod Reunion.   Have read where GL-4 should be used because of the brass synchronizers--but the 72 Chevelle service manual says to use GL-5.  Thanks

[wayne petty]

what's strange..

my local manual transmission shop has been recommending Non detergent 30 weight motor oil for these for years..    seems the needle bearings in the counter gear get more lube with the thinner oil..


world class T5 transmissions call for ATF.. for a lube.. and they don't seem to have much gear to gear wear problems..  they use ATF for the friction lined syncros..

[rumrumm]

I thought those transmissions required 90 wt gear oil. Am I wrong? I have never owned one, so I don't have first-hand knowledge.

[Uncle Bob]

what's strange..

my local manual transmission shop has been recommending Non detergent 30 weight motor oil for these for years..    seems the needle bearings in the counter gear get more lube with the thinner oil..


world class T5 transmissions call for ATF.. for a lube.. and they don't seem to have much gear to gear wear problems..  they use ATF for the friction lined syncros..

You probably already know Wayne, but in case it's of value to anyone else, SAE 90 gear lube is in the same measured viscosity range as SAE 40 crankcase oil.  Over the road trucks used SAE 40 for years in transmissions.  The extreme pressure additive for hypoid gears in rearends doesn't serve much purpose in an automotive transmission, that application probably resulted from a desire to minimize the number of lubricants on hand at a service facility.