diferential oil seal

[oakfall]

Hope you guys can help me out.

I have oil spinning out of the front end of the rear diferential on my 94 serria.

I have a manual but it is very incomplete and I need some info on how to replace the oil seal.I assume it's the oil seal.

 

Thanks,

oak

[the blur]

it's called a PINION seal. and the GM manual is very detailed about it.

[oakfall]

I really need to get a good manual.Can you recommend which one and where I can buy it.

 

Thanks again

[100R1]

I really need to get a good manual.Can you recommend which one and where I can buy it.

 

  Thanks again

 

<{POST_SNAPBACK}>

 

 

 

 

The best is HELM manual, this is the factory authorized repair bench manual

for my Yukon the complete set consist of 5 books.

 

Not cheap, be prepared to shell out over $ 100.00 for a new set.

 

here is the URL Helm manual web page

[GOT_NITRO?]

REMOVE THE DRIVESHAFT, USE A PIPE WRENCH ON THE PINION YOKE WHILE THE TIRES ARE TOUCHING THE GROUND (KEEPS THE PINION FROM MOVING) AND USE A LARGE SOCKET / BREAKER BAR ON THE PINION NUT. REMOVE THE NUT, WASHER AND PINION YOKE. POP THE SEAL OUT USING A SEAL REMOVAL TOOL OR A FLAT BLADE SCREWDRIVER AND A HAMMER. PLACE THE NEW SEAL IN THE HOUSING AFTER LUBRICATING IT AND HOLD IT SQUARE IN THE HOUSING WHILE TAPPING THE OUTSIDE LIP GENTLY WITH A HAMMER OR MALLET. THE SEAL WILL WANT TO MOVE AROUND AND ONE SIDE WILL USUALLY FALL IN FIRST. KEEP IN SQUARE IN THE HOUSING UNTIL IT BEGINS TO SEAT PROPERLY. YOU CAN USE A LARGE SOCKET OR PIECE OF PIPE TO DRIVE IT IN THE REST OF THE WAY. DON'T FORGET TO RE-TORQUE THE PINION NUT TO SPECS!!! THIS IS HOW I'VE DONE IT MANY TIMES IN THE PAST.

[MountaineerTom]

I just replaced the front one on my '99 and a Haynes manual for the new body styles covered it very well.

 

I'm in hte process of working on a techarticle/guide for the site.

[100R1]

REMOVE THE DRIVESHAFT, USE A PIPE WRENCH ON THE PINION YOKE WHILE THE TIRES ARE TOUCHING THE GROUND (KEEPS THE PINION FROM MOVING) AND USE A LARGE SOCKET / BREAKER BAR ON THE PINION NUT.  REMOVE THE NUT, WASHER AND PINION YOKE.  POP THE SEAL OUT USING A SEAL REMOVAL TOOL OR A FLAT BLADE SCREWDRIVER AND A HAMMER.  PLACE THE NEW SEAL IN THE HOUSING AFTER LUBRICATING IT AND HOLD IT SQUARE IN THE HOUSING WHILE TAPPING THE OUTSIDE LIP GENTLY WITH A HAMMER OR MALLET.  THE SEAL WILL WANT TO MOVE AROUND AND ONE SIDE WILL USUALLY FALL IN FIRST.  KEEP IN SQUARE IN THE HOUSING UNTIL IT BEGINS TO SEAT PROPERLY.  YOU CAN USE A LARGE SOCKET OR PIECE OF PIPE TO DRIVE IT IN THE REST OF THE WAY.  DON'T FORGET TO RE-TORQUE THE PINION NUT TO SPECS!!! THIS IS HOW I'VE DONE IT MANY TIMES IN THE PAST.

 

<{POST_SNAPBACK}>

 

 

 

What about measuring the pinion torque before removal and during re-install to the proper preload for the pinion bearing, pinion pilot bearing, pinion oil seal & differental case bearings?

 

this will keep the axle quies and keep form premature future wear

[GOT_NITRO?]

I ALWAYS TORQUE THE PINION NUT TO THE SPECS FOUND IN THE HAYNES MANUAL.

[MountaineerTom]

I rotated mine with the wheels off the ground, with an inch pound beam style torque wrench. It ended up taking 15 inch pounds to rotated it. As per the Haynes manual, I marked the relationship of the nut and pimion shaft and counted the number of threads sticking out of the nut. After all was replaced, reinstalled the nut to the correct amount of threads recorded earlier, then the Hyanes said to go 5 inch pounds more to make up the difference from the drag of the new seal.

 

That worked out well for me and have had no problems since (about a month).

[Peter_C]

There is a lot of bad info in those posts above. Turning torque is measured with the diff not installed. The torque spec also changes from when the bearing are new to when they are used. The best way is to just mark the nut and put it right back where you took it off from.

 

This leads to another question...why did the seal fail? When you raise the vehicle on jackstands or lift, grab the driveshaft before removing it and see if there is play in the pinion. If there is that is the reason the seal failed then the play needs to be removed. Also check the u-joints before removing them as they can cause problems and it is a good time to fix them.

 

Put some grease on the back of the seal to hold the spring in place, then gently tap it into place using something flat against the seal. Do not put any RTV on the sealing surface, and make sure the seating area is spotlessly clean.

[oakfall]

A big thanks to you folks for the help.All I have to do now is get that pinion seal out.Man, it's stubborn!

Thanks ,

oakfall

[unkleJ]

Pinion seal failures seem to be a common problem with GM vehicles. When I replaced my seal in my 91 s10 I used the same method as Peter C described above. I marked the position of the nut to the pinion shaft and reinsalled it to the same position. I had close to 35,000 miles on the replaced seal with no problems when I sold the truck. I hope this helps.

 

Jeff

[MountaineerTom]

My seal was cracked and what looked to be dry rotted, letting some fluid leak out.

 

I followed the Haynes manual, and all works well.

[asilverblazer]

Yes we (ehem I) need a guide.

[oakfall]

Well, job is done and I want to thank all you guys for the help. It turned out to be not that bad.The only hang up I have now is trying to get the filler plug out.It's really rusted in there. Maybe try some heat tomorrow.

 

Thanks again,

oakfall