The Stovebolt Site Forums The Shop Area Driveline Steering box

I have a steering box out of a 1941 1/2 ton, model AK that I have two questions on. 1: What is a good lubricant to use?
2: After bead blasting, I noticed a small hole (approximately .100”) about an inch in front of the fill plug. Should it be there? I can’t think of a reason for it, I don’t see a crack and it’s not a vent.
Thanks,
Ken

Ken, as for lubricant I mix 90 weight oil with corn head grease until I obtain a thick but pourable mixture. The fill plug is a good clue for you...GM intended the lubricant to be poured in and not forced in using a grease gun. The GM steering box lubricant was a bit thinner than fresh honey. To my knowledge it isn't sold any longer, though. The last I bought was in 1977. A lot of people claim they just use corn head grease but I believe it to be much too thick. You want something that is going to bathe your recirculating balls and all your steering box gears nicely and it must be self-leveling. If you turn corn head grease upside down, it won't pour out of the container. It is not self-leveling at all. I don't know that that little hole is...never noticed one before but I don't have a box from 1941.

My '41 gear box doesn't have that hole, it's not a vent. I use straight Corn Head grease from John Deere. Tractor supply has steering gear lubricant, or you can use CV joint grease used in front wheel drive cars. Grade 0 or 00 self leveling grease. I poured the grease out of the tube into a heavy plastic bag, then cut the corner off and squeezed it into the gear box. The more you move it around, the runnier it gets.

Do you know if the hole goes all the way in? Spray some cleaner or light oil or something into the box and see if it runs out the hole.

Can you shove a paper clip into the hole and see it through the large hole?

Ken - I read through Chevrolet Shop Manuals for 1938, 1940, 1941 and 1942 and none show there being a hole in the spot on the truck gear box cases. In someones mind perhaps, it might have made sense to put a hole there to allow for air to escape when filling the gear box through the threaded port above that hole, but then leaving it open to allow contaminants inside is counter productive.

I think you can safely plug the hole and move along with the rebuild of the unit.

To make lead rivets, I drill a hole the size of the hole I want to plug in a piece of metal about the same thickness, then take a tapered reamer I got from the local hardware store and ream out the hole to a taper but not so deep it comes out the back side. The hole should be straight with a taper at the top. Then cut off a piece of a tire weight or soft copper grounding wire. Pound the lead or copper into your tapered hole till you know its full. They push out from the back side pretty easy, now just put it into the hole you want to plug and hammer it it. If you really want to make nice rivets, use a piece of flat stock with half a hole to form the head of the rivet with as you hammer it into shape. I filled plenty of carburetor holes with this method with no leaks. Making the half of a hole in the flat stock was the hardest part!

How about 600 wt or 140 wt gear oil? The 600 wt is what I use in Model A Fords.
Thank you to all who answered my questions.

Here’s a photo showing the gear box on Sparky. Note that the filler plug does have a hole in the center. My assumption had been that it was factory delivered that way, but I don’t know for certain.

Guys - Per the 1929-54 Chevy Master parts Book the '42-'46 Steering gear box filler plug has a 1/8" diameter breather hole in it. Sparky, your plug would be correct. I need to go dig through the '41 book to see if that steering gear box used a solid plug with a vent hole in the housing instead?

Back later when I can provide more info.

Okay - The 1929-41 Chevy Master Parts Book does not list a filler plug of any sort for the 1941 truck steering box. Next best/closest things is what's listed as a "Bolt, steering gear housing breather" for the 1938-40 truck boxes.

Perhaps the hole in the housing was GM's initial thought for venting the gear box differently for 1941, but later replaced by the vented filler plug in 1942???