The Stovebolt Site Forums The Parking Lot Big Bolts 46 1.5 ton Pinion Seal replacement.

Hello gents,

I need to change the rear pinion seal on my 46 one and a half ton. I know where I can get the seal however is there anything special about taking the yoke out? Could someone possibly give me some directions to make sure I'm doing it properly? after taking the castle nut off does the yoke just pull out off of the pinion to where you can easily change the seal?

Thanks

You can get in trouble with the pinion bearing preload if you pull the yoke off without disassembling the rest of the diff. You should carefully check into that process before you pull the yoke. I am not personally familiar with that truck but some diffs use shims and you should be OK. Some use a crush sleeve and you would be in trouble.

Thanks, I'm familiar with the shim type diffs as my brother and I rebuild JEEPS. I was hoping I could just pull the yoke and replace the seal. I'm heading to Carters on Tuesday and will talk to Jimmy.

Thanks again

Lend-Lease 1.5, I can tell you only one thing. As a kid I ran into this and had a mess. My Dad smiled and said.....you didn't follow the exact directions did you. Saved one axel shaft as a pry bar. Doc.

If the '46 1-1/2 ton rear axle is the same as the later ones (and I'd be surprised if it isn't), the pinion is mounted with ball bearings and there's no adjustment, shims, or crush sleeve. The forward pinion bearing is a double row ball bearing, and it has a second ball bearing behind the gear. Everything is held together by a bolt-on bearing and seal retainer. All the adjustment is with the ring gear carrier bearings, so if you don't mess with that, it should be fine.
So it should be a piece of cake (relatively) to replace the seal. Remove the pinion flange, remove the bearing/seal retainer, drive the seal out of it, and drive in a new seal. Bolt the retainer back in place (pay attention to the gasket thickness), install the pinion flange and tighten the nut back on. The 47-54 service manual calls for 160-280 ft-lb of torque on the nut. That might be the hardest part. You'll probably need a flange holding tool to get that much torque on the nut. I would recommend NOT using an impact wrench.

Great, I was hoping that would be the case. I've got the military manual for model 4109 dated for 42 1 1/2 ton civilian version. I see the flange that they were talking about on the diagram I also see where the pinion seal is right next to the bearings. Something I'll tackle on a day soon.

When you drive out the old seal from the retainer, be carful to not damage the felt part that is sandwiched between the seal housing and the retainer. The felt (hard to source replacement) can be cleaned in solvent and reused.

Thanks, who knows if its still in there!

When you pull the the seal housing there may be shims around the bolt flange, just make sure you get them all back in and make sure your drain plug is pointing brown. I wasn't paying attention and ended up with the plug on the side
Lol

I have a 48” pipe wrench useful for holding U-joints.

Ed