That's the answer I was hoping for!

We used to dump our used motor oil and other chemicals out on the ground next to the garage until one day I realized that our well is right next to where we were pouring all the old oil. Now the oil goes to AutoZone and we don't risk drinking it.

 

OK, it's been a year and I'm finally getting around to replacing the transfer case seals. The case came out easily (I've had some practice removing and replacing it) and the two output shaft seals were easy to replace. The input shaft seal, however, is a bit of a puzzle. When I did the seals on my '98 Jimmy with the same case the front seal was retained by a ring with four bolts and was easy to remove. On this 1993 version I'm not sure what to do. The factory shop manual didn't have any information about removing the input shaft seal to replace it. Do I need to remove the bolts and the plate in front to remove the shaft seal or do I just pry the seal out as is?

Here's a picture of the input shaft on the case:

 

Wonder if there`s a way to filter it?

 

No ideas about removing that input shaft seal? If I don't find any other information I'll just try and pry it out of the bore next week.

 

Maybe under the plate with the 4 bolts. Remove the plate first?

 

That was my first thought. I removed the four Allen screws but the plate on the front didn't come out. I've done a lot of reading on the subject but haven't come up with a definitive answer. The factory shop manual didn't cover the input shaft seal; only the output shaft seals. Over on the ZR2 website someone posted a picture of this transfer case but said the cover plate has to come out to remove the seal. That advice applies to the later version of the transfer case that's in my '98 Jimmy but not necessarily this one. Another website said that the transfer case has to come apart and be separated to press the seal out from the inside. Yet another said that the seal can be removed from the case without taking it apart. None of those sources have enough details to really confirm any of those answers. I may just go at it with a screwdriver later in the week and see if I can drive the seal into the case on one side and remove it like a freeze plug.

 

Maybe the notch in the cover is there for a reason? Could try a punch and hammer to get it moving sideways, maybe loosen it a bit

 

OK, I figured it all out. The cover plate has to come off the front of the transfer case and the seal has to be pressed out from the back side. I started trying to pry the seal out as was suggested in other forums but that just resulted in chunks of seal coming out and little movement of the steel ring. I took the hex screws out again and started trying to pry the cover off. It took a lot of prying but I finally got it off. The reason it was so hard to get that cover off was because it had been sealed up with RTV silicone on the back side around the shaft bearing.

With the cover removed I was easily able to press the old seal out and press a new one in. I cleaned all of the mounting surfaces thoroughly and re-sealed the cover plate with black RTV silicone. I put blue Loc-tite on the four hex screws and put it all back together.

For posterity, if a future Blazer or Jimmy owner is trying to replace a leaking input shaft seal on their transfer case, the cover plate comes off and the seal is pressed in from the back side.

It will go back together on Wednesday afternoon when my buddy is off work. Shortly thereafter the Jimmy will go back on the road, preferably for some mountain off-roading this summer!

 

good news! glad you got it!

 

Me too! I was really surprised that the factory shop manual covered the two output shaft seals but not the input shaft seal since that seems to be the one that's most problematic. I'm just glad it's done. I hope I never have to get under this particular truck again. I just want to run it up in the mountains this summer and enjoy it!