'52 GMC 150, 3/4 ton, 125" wheelbase, same as Chevy truck as far as this seal goes I think. I need to replace the seal that keeps transmission gear lube from leaking out the back end of the enclosed portion of the "torque tube". These 3/4 ton trucks have the ball type cover over the U joint immediately behind the transmission and about 2 feet of "torque tube". Inside the rear of the tube is a seal that I need, a snap ring on the driveshaft, a sealed bearing and a snap ring to hold the bearing into the shaft. A splined U joint yoke bolts to the end of the enclosed driveshaft and connects to the rear, exposed, driveshaft and on to the rear end. The seal is designed to run on a 1.5" OD shaft. I don't know the ID of the torque tube where the seal resides. GM part number is 3689176. Anyone know where to get this seal?
3/4 T AD driveline I have often wondered why it might not be simpler to switch out the sm420 parts from an old 1 ton truck to convert to an open yolk. Would it be possible to then have a driveshaft fabricated to yolk into the 3/4 T open drive rear end? I believe I have the 1 ton yolk from an sm 420 I switched into my torque tubed 3100 some years ago if you think this could work. I assume there is a frame crossmember in the way as well. Good luck finding the parts you need. Jim
Seal Bill I found the seal at olds obsolete.com. Part # and description sounds like what you are looking for. $45 though not cheap!
I took the trany out of a 48 grain truck 1 1/2 or 2 ton. Save the old drive shaft. I took the end that bolted to the trans and the measurement to Inland Truck in KC and 150 later have a great set up. Nate did tell me the check final drive gear and it was 1 to 1. The grain truck only had 50k trany was in great shape and so was the cab. Papy
Thanks for the suggestions on getting rid of my "worst of both worlds" 1/2 torque tube, 1/2 reqular driveshaft stock driveline guys, but I think I'll try to keep it. A member over on the OldGMCtrucks forum had an old paper catalog that crossed the GM part number to a modern seal and my local NAPA has one in stock. I'll pick it up in the morning. I've ordered the gasket/shim kit for the ball along with a new set of bolts and lock pieces for the forward U-joint from our host. As soon as the parts come in I'll try to con Bilbo into giving me a hand swapping out the seal, as he claims to be an expert at working on the ball seals and shims. Hopefully, I'll take a few pictures for Ziggy.
OK, Bill, glad your in business. I was going to suggest you measure your old seal: ID, OD, and thickness and then go on the Timken or National seal site where seals are listed by dimension rather than number.
During my search for the seal I needed I came across an Oil Seal cross reference book on SKF's web site. It had a bunch of GM part numbers in it, including the one I was looking for. Only bad thing is that it is not searchable by computer, you have to eye-ball the pages. Good news is that it is in part number order, so it is easy to find what you are looking for if you have the (GM for instance) part number. Here is a link
Thanks, Bill! I'm sure more that I would appreciate the visuals. Good luck with this project. BTW, since I already said "thanks" for taking pictures, I guess you are now committed to doing just that.
Bearings & Seals Glad you found that interchange Bill ; It's the easiest and best way as once you have the current p/n running one down is dead easy . I don't think your drive line is a bad deal at all . Still working at 70 years old and only needs an oil seal ? nothing ever made with ' Hotchkiss Drive ' will ever do that .
