The Stovebolt Site Forums The Shop Area General Truck Talk Torque tube plug Mystery?

New to the site just days ago and can't believe how helpful everyone has been. I am new to the first series trucks and have many questions. I am trying to solve as many as possible by myself, but one eludes me. When installing a new trans cover/floor panel I noticed a small square headed plug on what I believe is the forward top of the torque tube, just behind where it connects to the 4 speed trans. This plug is opposite the speedo cable connection. I removed it and looked inside, and saw no fluids. I was wondering if one of you kind folks could please help me understand what this plug is for? Maybe it's a dumb question, but I don't want to screw things up by not asking. Thanks a million to whomever can assist me in this Mystery. Mannymoejack

Welcome manny, what year truck do you have?

Manny

Take a picture to confirm, but I think you are talking about the plug that allows you to lubricate the universal joint. There needs to be fluid in there, (90W gear oil) to help extend the life of the u-joint. This spot is often missed and cause good u-joints to go bad.

1953, 3/4 ton, long box, 216, 4 speed on the floor. Thanks for the help.

Thanks, It would have been a major blunder if I missed doing so.

I think that hole, as SWEET states, is for filling the u-joint enclosure, but lubricant also moves between the transmission and that enclosure. By adding lubricant via that hole (after opening/closing the u-joint enclosure), you ensure that the fluid level in the whole assembly (transmission and u-joint enclosure) does get too low (from fluid moving from the transmission to the u-joint enclosure - seeking "a level").

If I am wrong, we'll hear about it.

Thank you very much for the explanation. I originally purchased the shop service and repair manual, expecting this type of info to be there. I realize now, that the owners manual really is a better place to find all the regular service info and specs. Funny, the new car/truck owner's manual don't have near the info of these old Chevy manuals. They really don't build em like they used to.

I know on my 37 it states that the battery ground cable bolt hole is where I fill my torque tube bell that encloses the u joint. I find the manual for my year in pretty vague and purchased a Audels automobile guide copy right 38 to 47. Audels pub., awesome manuals back in the day. It covers much more stuff in detail, and many makes and models. Kind of the bible for anyone who worked on their own stuff or was a garage mechanic in the day. It even covers diesel motors, jeeps and tractors. It is black, looks like a bible and has 1607 pages of information to dive in to.

A Motors Truck Repair Manual is mighty handy too. I've been using Motor's Manuals for nearly 50 years but have never heard of the Audels manuals. I'm going to check it out though. I just found one for a reasonable price on the auction site and bought it. Thanks for the tip, wasat.

Step 10 (48-52, at least).

Universal Joint [lubrication] 1938 (as described above for 1937) - NOTE: "This initial lubrication is necessary to take care of the universal joint until normal lubrication takes place from the transmission."