The Stovebolt Site Forums The Shop Area Driveline Torque tube Alemite grease fittings

Anyone know why the torque tube on a 34 1.5 ton has Alemite grease fittings? Can gear oil be pumped in threw them?

Where is the fitting (fittings) located?

On later torque-tube trucks, a grease fitting near the top of the u-joint enclosure was used at the factory to put gear oil into the u-joint enclosure. On later trucks, the gear oil from the transmission will also eventually settle into the u-joint housing from the transmission (this might also be the case on earlier trucks).

People have speculated on why that fitting was installed/needed/used. Maybe for a quick leak-test on the u-joint housing? Maybe for a a quick "pre-fill" of a metered amount of gear oil into the u-joint housing, before filling the transmission?

If I have the correct sized pipe-plug available, I remove the fitting and plug the hole. I do not want anyone in the future mistakenly/unnecessarily putting chassis grease into the u-joint housing.

There is a fitting on the transmission were the ball joint connects, one midway on that drive shaft, one on the housing were the next ball joint connects and one halfway on the next section of drive shaft going to differential. I was thinking there must have been some sort of pump used back in the day for gear oil that would work on alemite fittings.

Tim hit the nail on the head, the fitting was used as an easy way to inject a specific amount of gear oil into the u-joint housing. This is one of the most forgotten lubrication points on these trucks. For a half-ton (and possible bigger) the shop manual calls for 1 pint of gear oil in this area.

What ever you do, do NOT use grease. I have seen what grease does inside this housing and believe me, it is not pretty.

Only thing I'm wonder is why there would be fittings part way down the housing shaft??? I'd assume the differential cover has a fill hole in it, so why have a fitting part way up the housing from it? Unless there is a seal at the pinion end of the differential??

I think he will find that the one half way down the torque tube is a vent not an Alemite. The vent looks a little like a old Alemite fitting.

How do you get 1 pint of gear oil in the ball? My truck is a '41 GMC and is a long wheelbase model. It has a short torque tube and ball about a foot long exiting the transmission, then another tube and ball on the drive line. I always thought they got oil from the tranny...I am hearing noises and I think I know why now...I know there ain't no oil in either ball. Please advise. Jim

The front ball should get some oil from the transmission itself. There is usually a plug you remove to prefill the front ball on the shortwheel base trucks. Not sure about the rear ball on the GMC.

I've found an old grease pump that i'm going to try and use to put gear oil in, if that does't work i'll just remove the fitting and use a funnel. On another site I found some heavy gear oil that is compatible with these older vehicles, it's made by Chevron for industrial use, it's called Meropa 680 and 160w or better. The blue oval folks use it in their model A gear boxes and differentials.