Ditto on all of the above. Hypoid gear lube is for rear ends- - - -not transmissions, as it contains high film strength additives intended to deal with the loads of spiral bevel gears that mesh below the centerline of the ring gear. If lubricant in a transmission is too slippery the synchronizer rings can't get a grip on the cone clutch part of the gears to match the speed as the synchronizer collar meshes with the gear. Mineral oil only is also needed in Fuller Roadranger twin countershaft transmissions. Hypoid gear lube causes carbon deposits to build up on the synchronizers and makes them fail prematurely. I visited a Fuller repair depot in San Francisco once where they had 55-gallon drums full of ruined brass synchro blocker rings.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!