tcase issues

[sdeppe]

i have a 02 chevy silverado 2500hd diesel and i just bought it and has 168,000 miles on it and the issue i have is with the tcase the first thing to list is the slip yoke catching when you let off the brake from a stop it would clunk and so i knew i would need to replace it with the nickel plated slip yoke. so i have not done it yet i just took it off and greased the slip yoke and temporarily make the noise go away but when i took the slip yoke out no fluid came out of the tcase so i knew it was not full so i went to take the fill plug off and it was already striped out so i torched it carefully and got the plug off and still no fluid came out so that was not good and then i took the drain plug off and not even a half of a cup of fluid came out and a small piece off plastic came out as well and i knew that was from the shift fork if i am correct??? so now i got a new drain plug and filled the tcase with auto trak II and now its leaking fluid from the slip yoke or output shaft seal and my question is do i replace the seal or the slip yoke or both?? or what should i do and where do i get slip yoke from if i do the yoke. and there is no noise from the tcase and the 4wheel drive works fine and no other holes or leaks from the tcase. thanks for the help!!

[DmaxMaverick]

Welcome aboard!

I'll start by apologizing for having no good news for you. I'll keep it as simple as I can.

The fluid you used is the wrong fluid. Autotrac II fluid is for automatic/electronic controlled TC's, like in the 1500 and 2500 (LD), NOT the 2500HD. The push-button system is only an electrical-mechanical version of the shift-lever mechanical. It should be serviced only with Dexron III fluid.

The reason for you low fluid level, the leak, and the plastic piece, are probably (very likely) caused by the same issue. The early transfer cases suffer from a defect which affects a high number of trucks. The pump rubs a hole in the case, causing the fluid to leak out (in the area forward of the rear seal), and eventually self-destruct. You are probably seeing the early signs of it. You will probably need a rear cover, an overhaul, and one of a few remedies to prevent the problem in the future. More info on that as you need it.

The rear end "clunk" is usually cured with regular service of the correct grease (high-pressure lithium or moly). I know of several chrome/nickel replacements that didn't stop the problem. Using synthetic ATF service fluid stopped the condition in every case I'm aware of. This condition is only a matter of convenience/aesthetics, and poses no mechanical issues.

[Kennedy]

OK the drain plug was stripped out, but you replaced it?

Do you mean the head was rounded off?

I find it hard to believe that the plug would strip but not the soft magnesium alloy case.

Either way, plan on doing a pump rub fix before you get bit again. That fluid had to escape somewhere.

Depending on condition I might suggest replacing the rear case half and output seal as you will then get a new tailshaft busing as well.