'01 HD2500, loosing Xfer case lube

[chessy56]

~400K on it and I've been noticing the under body around the front prop shaft U-joint is always wet. Every now and then, I'll have to add some tranny fluid to the Xfer case- appears to be leaking past the output shaft seal.

Dealership just installed a replacement seal ($80 + $100 labor- ouch!). Still leaking. Dealership recommended replacing the bushing & seal but didn't stock the bushing (another day on the rack... no thanks).

Thoughts? Is the bushing & seal both required? Can this be replaced with the case still mounted in the truck or does it have to be dropped for rear cover removal?

Thanks folks.

[CoyleJR]

I have posted this several times before, you can do a search for tail shaft leak. My 2006 was leaking in the same area as your 2001 is. I suspect that your front u-joint is dry (no T case fluid on it) and the rear of the T case is also dry. The only thing that gets wet is the floor of the cab. There is a flat plug in the back of the T case/drive shaft yoke in front of the u-joint with a small weep hole in it. My truck was leaking around the seam of the flat plug. It only leaked when in motion and never left any fluid on the U-joint right next to it. I cleaned the yoke and plug with brake parts cleaner, sand paper and a toothbrush size wire brush. After it was clean I sealed it with JB weld quick dry and it hasn't leaked a drop in more than 100k miles. Additionally, I did seal the weep hole with JB weld even though the leak was at the seam and I also covered the entire area with clear silicon gasket sealer.

You will need to remove the drive shaft to try this fix but you will not leak much fluid. A quick trip to Walmart and $10.00 will get everything you will need. If you try this fix please post the results. If the dealer replaces the seal again and the rear T case bushing I would be surprised if the leak stopped without replacing the yoke.
Good luck
John

[chessy56]

Thanks for the reply. The U-joints were both replaced a couple of thousand miles earlier. They were indeed bad and I thought that the extra vibration from the prop shaft was the cause of the seal failing (that and 14 years/360K miles). The new U-joints didn't resolve the leak, so I figured the damage was already done- was hoping the new seal would do it.

I seem to recall seeing a small weep hole near just ahead of the output seal (bottom side) and there was a small amount of fluid around that hole. Front U-joint is pretty much dry. This is a replacement rear case cover as the original exhibited the pump-rub pin hole.

I'll look for that plug....
Thanks.