Thanks to those who have helped me through my project already, especially the CAPTAIN. So far All brakes are done, front end rebuilt, fuel pump and filter installed, Trans filter and all fluids changed. Now I am ready to pull the transfer case tonight. Once I get it out, do I pull that front cover on the case to replace the input seal or do I just pull and replace it with it on. Also do I get the Timken seals or is there another recommended seal, OEM or another brand. This is on a 98 LT 4door 4X4. Thanks

 

After removing the transfer case, the seal can be replaced without any disassembly of the case. If you're doing this due to transmission fluid migrating into the transfer case, make sure you replace the gasket between the transmission and the transfer case, and the vacuum switch on the transfer case. Make sure the vacuum lines do not have trans fluid in them. If so, clean them out, or better yet, replace them.

As for the seals, Auto parts stores should have them, or the dealer. The gasket you'll probably end up at the dealer or a transmission shop.

 

Captain,


Thanks for the quick reply. I will owe you a drink when this project is over. I already have the gasket and vacuum valve. Just was wonder if the brand of the seals matter. I am replacing all three while I have it out. Thank goodness there was no ATF in the vac lines.


I will be contacting you in the next week or so to get the details on the lower intake procedure. I have all the factory manuals, so anything that differs from their instructions would be appreciated.


Thanks again I owe you big

 

When you say "factory manuals", are they GM factory manuals? Please don't say they're Chilton or Haynes If they are, leave them on the shelf. There are a few threads in the How-To section of the forum, they will be far better

 

No they are the factory manual 3 book set

 

Good job with the manuals!


From what you have described, you must have the 3 button 4WD switch on the dash, is that correct?


The 3 volume set doesn't get into too much detail about assembly repair procedures like transfer case, alternator, starter etc. but it will explain how to R&I the case. The seal pulls out and it would be best to use a seal driver to install the new one, (auto parts stores rent them).


For the intakes, the manual and an inch pound torque wrench will be your best friends Make sure you use Felpro MS98002T gasket set.

 

Yes its a 98 with a 3 button. That leaking seal on the transfer case is a bear to get out, bought a seal puller today to see if that will work better. I will go to auto zone to rent an installer.


Thanks for all your help

 

Been over 7 years, how about an update! Haha I need to do the same to my 98 LT 4x4. I already had pulled the dash and replaced the vacuum unit for the hvac and it works great now, this was before I knew what had caused the problem. I disconnected and capped the vacuum from the engine leading to the transfer case as to not get fluid back into the hvac once I realized it, but I really miss my 4x4 so I need to replace that input seal, vacuum switch, clean out 4x4 actuator and replace the vacuum lines. Just wondering if you have any tips you could pass along, I have read every thread on every site I could find and feel pretty comfortable but still. My biggest concern is R&R new seal and the seal or gasket(s) between trans, adapter, and TC(I see a transfer case adapter seal part #15969051 - a big o-ring) besides the gasket . I don't like to start a project until I know everything there is to know. Anything helpful would be greatly appreciated, hope yours is still with you running strong!

Jimmy