PENION SEAL

[8543bob]

Hey all, I compledted my summer to winter change over: put the canvas top on, checked and filled all the fluids. All were good except the rear dif. the pinion seal is leaking and slinging oil pretty good, the good think about that is it keeps the bottom of the bed from rusting. I went thru the TM and all seems pretty streight forward to R&R. Is there any thing I should look out for thats not spelled out in the TM??
THANKS BOB

[WarrenD]

It ain't easy. Been there, done that. The worst thing is getting the old seal out. I tried several of the recommended ways and nothing worked. The best way I've heard of is to find a pipe about the same size as the metal face of the seal. Cut ends flush and square and weld a flat bar to one end and tack weld the other end to the seal. Beat on the flat bar until seal comes out. I didn't try that as I don't have a welder. Welding metal to the seal face and using a slide hammer is also recommended, but again, no welder here. You could also try to drill 4 holes in the metal face of the seal, thread in sheet metal screws and use a puller against the screws. They pulled out when I did it, I re-drilled and they pulled out again. I resorted to using a Dremel tool with the abrasive disk and was able to remove enough material to get it out with a big pry bar. Be careful you don't mess with the center shaft.
Use a NOS leather seal and soak it in neatsfoot oil for a day or two before installing. Just before install, burnish the leather seal surface with a brass rod. I used a small length of 2x4 and a hammer rotating around with small taps to set the seal. Check your companion flange for any sign of rust or wear, use a speedi-sleeve or new flange. (I used a speedi-sleeve, worked out well as my flange had some visible wear, measure carefully!) Before installing the washer and nut, apply some gasket sealer to the inside surface to keep the lube from leaking out around the nut. Torque nut to 100-200 ft-lbs and insert cotter pin. When I was done, I had a slight leak from where the seal contacted the housing, cleaned it up and forced some gasket sealer in the crevice with my finger. Seems pretty dry now.
Before you drive it, check and replace the axle vent. If it isn't working, you'll pressurize the diff and force lube out the seals (pinion or wheels).

[pfrederi]

I got mine out recently with the sheet metal screw/slide hammer approach. I drilled 8 holes around the seal then worked my way around with the slide hammer just a couple of slaps on each hole. Had to replace the #10 screw a couple of times as the threads began to fail. Took 3-4 trips around before the seal began to move. Took a few more to finish the job...It held on for dear life to the bitter end.

[Sal]

Warren, I was under the impression the Companion flange on the pinion was to be tightened to 300 Ft Pounds ?

Sal

[WarrenD]

I could be wrong, but the 300 foot-lbs is for the flange out of the transfer case. I was told ~100-200 for the pinion.

[Sal]

I have 140--160 Ft pounds for the transfer case Flanges. I got these measurements out of TM9-8031-2 Page 507.

Sal

[WarrenD]

Always safer to go by the TM's than word of mouth...

[Cal_Gary]

I'm swapping my lower transfer case seal on Monday-same principle as the pinion seal so I will take pictures and post as I go....
Gary

[8543bob]

Thanks all for your input. Right now I dont know if the R & R will be my last job before winter, depends on how long the great weather in the esat holds, or my first after winter. I will wait till I see the pics, in any case BOB

[WarrenD]

If it's just going to sit for the winter, I'd wait to do the seal until you are going to drive it. Seals hate to sit.

[Cal_Gary]

Damn! The forum photo limit has been reached so I can't post the pictures? I'll email Robi and MM to see if they can help.

Anyway, here we go:
Get the tools,
Drive the chisel into one edge of the seal (remember to use a big hammer)
As the seal moves inward, it provides a gap on the opposite side,
Drive your screwdriver into the opposite side and pry,
As the seal turns further, use your vise grips to finish pulling it out,
Done in less than 10 minutes (including snapping the pictures).

Install the new seal using wood or a brass drift to drive it in. I also installed the speedy-sleeve and buttoned it up-just need to add GL90.
Hope this helps,
Gary

[cuz]

Just put the photos in a G741 album and link them here.
http://www.g741.org/photogallery/main.p ... 2Fmain.php

[Cal_Gary]

Never noticed this feature, Cuz-I'll try it later today!
Gary

[MSeriesRebuild]

If you have the original 5.83 ratio gearing in your diff, pinion nut torque is 300Ft lbs. If you have the 4.89 ratio gearing, pinion nut torque is 160 ft. lbs.

The seal puller in the photo a couple of post prior doesn't work. We have had one for years, an original that is exactly like the one pictured; nice looking tool. Tried using it a bunch of times, it has never pulled the first seal; it's totally worthless, so if you are thinking of purchasing, don't waste your $$.

Leather seals are also worthless unless you like a seal that drips. Redi-sleeves don't work that well with a leather seal, and usually leather seals leak and continue to drip oil in spite of it, as they are designed to work with a rubber lip seal. ALWAYS coat the housing bore with anaerobic sealer before pressing in a new seal or it will leak past the outer seal case of any seal. Oil will also leak past the pinion shaft threads unless you seal the under side of the nut liberally with premium quality silicone before tightening.

[cuz]

The photo was posted just to give Gary an idea how the linking of photos work. It was not put there to sell or promote the tool. However the one I have has some special magic i guess because I have used it often to pull this type seal without any problems.