Rear diff pinion seal removal rockwell PR75

[Mooseknuckle]

I'm having some trouble removing the rear diff pinion seal on my Timberjack 230. 
I took the u joints apart and slip yolk out. Used tge air gun to take the big nut off the pinion shaft    Took the yolk out.   
The seal looks like its metal then a rubber gasket then a metal centre another rubber gasket the metal again.  I'm basically ripping it apart as it diesnt want to come out.  Any tricks to getting it out?? 

  

  

 

[loggah]

unbolt that pinion seal cover and you should be able to drive it out from the back,you already got the hard part done.

[Neilo]

I think they go in from the back. Like Loggah says, take the retainer off and drive it inwards.

[Mooseknuckle]

Ok, the good news is the seal is out now.  But the bad news is when we took the 8 bolts out of the cap we pryed awayand damaged some of the shims until we realized that the cap just pops off. 
So now we have to get that plate out remove the shims and get new ones made up.   
The problem we face now is something is holding that plate on.  Is that bearing holding it on?? Any and absolutley any help woyld be appreciated.  I hope i did mess it right up. 
I think we determined that its a Rockwell PR75 but below is a photo of numbers on the top of the diff. Maybe that will verify what it is. I have also included pictures of the rear diff as it is now and the seal. Of course we mangled the seal exactly where the numbers were. Does anyone know a napa xref seal number for it??

  

  

  

  

  

  

 

[HiTech]

Haven't done one in awhile but if I remember that bearing is a tight fit and yes it is probably holding the cover or pate on. I also believe there are drilled and tapped holes for insertion of bolts to push the cover or plate off. Where these holes are you will also find holes in the shims so they are not hurt when the bolts push the cover off. Be sure to line the shims up the same way when replacing them. When reassembling you may even have to use bolts to draw the bearing and plate back on. Once it reaches a certain spot it will come off easily or start easily. You will have to draw it all the way on with the bolts. Good luck. 

[Mooseknuckle]

Ok sounds good Hitech.   I'll give it a go.and see what happens. Doe it look like a PR75 from the pics?
I'm in close to Barrie Ontario. Does anyone know where to get part for this kind of stuff around here?
Once again thanks Loggah and Neilo for your help ,always appreciated. Neilo would you have a schematic for that Differential/axel assembly? If my memory serves me correctly i think you mentioned that you believe its a Rockwell PR75.

[lopet]

I would try  Preston in Sundridge , dealt with them before. If they don't have it they can get it but they're not cheap . 

[Neilo]

Yeah, as you now know you only wanted to take off the seal retainer, not the bearing carrier.

The bearing carrier has two taper roller bearings in it with a spacer between them. All of this is on the pinion gear. At the inner end of the pinion, there is a ball race that is held in with a lock ring.

For you to get the bearing carrier off the pinion, you will have to move the inner bearing you can see along the shaft (with or without the carrier). Be careful prying on the pinion and carrier as a whole as it may break the lock ring. A bearing puller would be a better idea.

[Neilo]

Oh, shims are 3 or 5 thou.

[tantoy]

MooseK, I need to do my PR52 seals soon, so thanks for the lesson. Question, how did the yoke look where the seal rides. Was it grooved up and could you speedy sleeve it if needed?

[ohiowoodchuck]

Try a big truck shop for the seals. Rockwell axles were put in tons of semi's etc. Just because it has plantearies on the ends doesn't make the center part any diffrent then the rest of them.

[Mooseknuckle]

Hey Tantoy, the yoke had a very slight groove in it so i ordered up a speedy sleeve. They also ordered a new seal off of measurements. I should have it all in by Monday.  I got the stuff through B&B Dixon which is Napa's competitor where I am. I also sent the pictures to Timber Parts in New Brunswick. They have tons of parts and seals there as well, and they ship anywhere. Their mechanic looked over my pictures and advised that i will be good to clean and re-align the shims without removing that yolk plate (thank God) 8)
Put the seal in and speedy sleeve and bolt it back together.  I had another mechanic look it over as well and he said the same thing and he has worked on a lot of Heavy Diffs. FYI the seal was 16.00 canadian and the speedy sleeve 38.00 Canadian 

[Mooseknuckle]

Well just about got it all back together. I tried lining the shims back up but it proved to be to difficult. I ended up taking Neilo's advice and my buddy Coluch used his gear puller.  It worked excellent and popped that plate with the outter bearing right off. I took all the shims out straighened them all back up.  Cleaned and buffed all parts.  Installed the speedy sleeve and new seal.  Just about ready to put it all back on.   But before I do so, does anyone know the torque spec for the pinion nut?? Below are

   some pictures of my parts layed out.  Hopefully this will assist others when working on their Diffs!


  

  

 

[Neilo]

1 inch pinion thread diameter is 300-400 ft lbs
1 1/4 inch pinion thread diameter is 700-900 ft lbs
1 1/2 inch plus pinion thread diameter is 800-1100 ft lbs

[pdxh20]

Just dug into my PR75 front diff on a '74 IH S-8 skidder I'm fixing up. My tin cover that holds the seal is demolished and there was only about 1/2 cup oil and a quart of water in it. Did the R&R on the big pinion bearings but the lock ring is gone on the pinion shaft and it's groove would need to be "rebuilt", plus all that's left of the bearing is the inner race on the shaft and the outer race still in the case. Lot's off oil goo and busted bearing parts in the bottom. Hoping to find the tin seal cover but I guess I can fab one up if I have to.

Anybody know if I have to remove the differential carrier (all those bolts !) to get the the pilot bearing out and really clean everything out before reassembly or will it be good enough without the pilot bearing and do a fluid change soon ?

Happily I have the parts book, and a bunch of local shops & distributors and will ask tomorrow but just curious since y'all seem to know what will work on a low speed application like a skidder as opposed to high speed highway trucks...Thanks !

[Neilo]

I would take the carrier out if you want it to last. A second hand center might be better if it is really damaged.

[pdxh20]

Thanks, I'm sure you're correct. I can't believe it actually worked at all the way it was. NO bearings at all, the just the cups. The only thing keeping it "in place" never mind preload, shims or contact areas (!) was the driveline was too long and held the pinion "in contact" with the ring gear. My use will be occasional light duty, but I think I want to keep the machine. Problem is I want to do all this work in the shop, not in the gravel where I dragged it off the truck. Pulling the axle shafts and that heavy carrier and ring gear out there and making more mess sounds like un-fun.

The pinion and shaft feels pretty rock solid on the new bearings. I'm half hoping I could flush out the rest of the debris and goo and put it together enough to get it in the shop without towing it (steep driveway past the house) but not have to re-do it first thing. The rear is missing a driveline and in unknown condition so the front is all I've got for now. Once it's in the shop I have overhead and portable lifting, air, lights and a steel floor. Tomorrow will tell more when I go over to the big parts dealer/repair shop. I understand it's a piece of precision machinery and the planetaries probably also need gone through too. At the minimum fluid change & inspection.