Going farther than I intended

[Jack605]

Bad day

Decided to go to the shop to do a little work on the truck. I removed the rear end a week or two ago so I was going to do a little rust removal. Broke my right angle grinder, got the rear springs stuck under the fork truck when the fork truck ran out of propane so I moved onto sandblasting a couple of parts to only realize that someone has been using it without the shield on the glass. Okay to late to do anything about it now. And to top off my day I broke the last tip that I have so now I am home sipping some Wiskey.

[Jack605]

Rear axel

So I am into re-doing the seals on the rear axel, Who ever was in there last did not install an oil seal should I look deeper or just go ahead and install my new seal and be done with it. The visual inspection was good the bearings look good. I was looking through my TM's and could not find the one for replacing the oil seal on the differential some help here please.

[Desoto61]

Pulling them is notoriously tricky. You'll want to drill and thread in some screws and use a puller. Think I have some pictures in my thread.

Obviously pay careful attention to the wear area of the yoke. I highly recommend the adapter that M-series offers, not cheap but it's a better alternative to the old seals.

[Jack605]

Tm

Anyone have the TM number for replacing the seals on the differential? getting ready to do this on Wednesday. Got the axel seals done over the weekend with the boys they really enjoy working on the truck unfortunatly we spent half a morning working on the sand blast cabinet, the cabinet still needs work but it is getting there along with the truck.

[Desoto61]

Which seals on which differential? There is only one seal on the actual differential itself. The number I turned up is National (Federal Mogul) #6127.

VPW has them, as does Midwest, probably cheaper than you'll find from a local parts place, and I'd bet they'll have to order them too.

If you look around here though you'll find that it's not the best option, it's a leather type seal and will not hold up over time like a modern seal. I highly recommend contacting M-series for a pair of their conversion kits. Money well spent in the long run.

[Jack605]

Replacing the seals on the differential and it has 1/16" of play side to side. I am no expert but this cannot b,e good.

[Desoto61]

Replacing the seals on the differential and it has 1/16" of play side to side. I am no expert but this cannot b,e good.

It's not a very good evaluation of the unit as it sits in the picture. The drive shaft yoke is what pulls the pinion gear against the bearings. So the only thing keeping it from falling to the back of the differential is the ring gear in that picture. I would expect you may see some significant movement with that yoke removed. If you still have it with the yoke installed and torqued THEN I would worry!

Make sure you look at the yoke for any pitting or wear, it probably needs to be sleeved before putting the new seal in place. Also, a dab of RTV on the washer under the pinion yoke bolt will prevent any leakage around the splines, which has been known to happen as there is a passage to carry lubricant up to the upper bearings.

[Jack605]

It's not a very good evaluation of the unit as it sits in the picture. The drive shaft yoke is what pulls the pinion gear against the bearings. So the only thing keeping it from falling to the back of the differential is the ring gear in that picture. I would expect you may see some significant movement with that yoke removed. If you still have it with the yoke installed and torqued THEN I would worry!

Make sure you look at the yoke for any pitting or wear, it probably needs to be sleeved before putting the new seal in place. Also, a dab of RTV on the washer under the pinion yoke bolt will prevent any leakage around the splines, which has been known to happen as there is a passage to carry lubricant up to the upper bearings.

I understand what you are say with the drive shaft yoke pulling against the bearings. What worries me is the side to side movement not the in and out movement, I have over 1/16" movement side to side on the drive shaft yoke. I have the sleeves and am ready to install.

[Desoto61]

I understand what you are say with the drive shaft yoke pulling against the bearings. What worries me is the side to side movement not the in and out movement, I have over 1/16" movement side to side on the drive shaft yoke. I have the sleeves and am ready to install.

But the bearings aren't forced to sit in their cups with no tension on the pinion. The upper cone is held in the case with a special nut behind the seal. Until you put some pressure on that cone, it's free to move around inside the housing, and it woudn't need much end play to create a decent amount of lateral movement.

If you really want to test it, wait till you pull the seal, then bolt the yoke back on and torque it and see what you have. That will put everything in compression and there will be no support from the seal. If you still have lateral movement, THEN I'd worry!

[Jack605]

But the bearings aren't forced to sit in their cups with no tension on the pinion. The upper cone is held in the case with a special nut behind the seal. Until you put some pressure on that cone, it's free to move around inside the housing, and it woudn't need much end play to create a decent amount of lateral movement.

If you really want to test it, wait till you pull the seal, then bolt the yoke back on and torque it and see what you have. That will put everything in compression and there will be no support from the seal. If you still have lateral movement, THEN I'd worry!

I got it, did not realize that the bearings were cone type bearings. Thanks for the help now I just have to pull the seal and install the sleeves. Sometime next week when I have time to try to pull the seal again.

[Desoto61]

It's a very HD design with three pinion bearings. I have some pics in my thread, nothing perfectly clear but you can get the idea.

[Jack605]

Got the seal out it was very tight. Used a different method to pull the seal worked great when the slide hammer was not working at all.

[Jack605]

Someone has been beating on the differential end you can see the splines are a little flattened and the flange shows signs of being pounded on

[Jack605]

Another picture