I have an 03 duramax with a badly bleeding tranny. Has 140k miles and started leaking a few months ago. Now its pouring out! Leaks most when in park. The tranny fluid is coming through the dust hole and silver plug on the bottom center of the bell housing. This leads me to belive that its the convertor seal or at worst a cracked convertour?

Which is more likely?

Gonna pull the tranny this weekend, any helpfull hints what to look for? Where to get parts on the weekend? etc.

This is my daily driver so i kinda gotta be in and out, just doing some homework, any help would be much appreciated. Thanks

Either. If you find loose TC bolts, look for cracks around the lug welds.

What trans fluid have you been running? Dex6 makes input seals harden and crack.

I have been keeping it topped off with dex/merc. I'm now going through about 2 quarts every other day. Driving about 50 miles a day. Thanks crafty1, that's good

Anyone know where I can see a good diagram of the tranny? (online) I have been through the sticky post about 10 times on how to remove the allison, but I question how the seals work etc.

Thanks again

The pump input seal presses into the nose of the pump body. The newest P/N 29546682 has a dust lip to keep abrasive dirt away from the sealing lip and is made of a more expensive type of Viton that is resistant to the chemicals in DEX6.

The lug weld cracks would be at lugs remaining tightly bolted if some have loosened. Loose lugs will have significant rust on the faces from fretting. These cracks are typically hard to see. Best to clean off the sides of the welds with carb cleaner and dry with paper towel. Cracks will show up from oil weeping out. They typically extend radially out from the weld over the radius of the TC cover.

Thats great info! I'm a structural welder by trade so I should be able to spot a cracked weld pretty easily.

How about parts? Is the seal a dealer part?

Thanks for the part number.

Yes. It will probably be less expensive from an Allison distributor if you have one in your area. Some medium duty truck places that have Ford, GM, Navistar, or Freightliner medium trucks may be able to help too.

Great, thanks again for all your help. Much appreciated.

How about any good diagrams for entire tranny? last question:rolleyes:

Great, thanks again for all your help. Much appreciated.

How about any good diagrams for entire tranny? last question:rolleyes:

http://www.compnine.com/index.php?t=1&year=2003&majorgroup=04&supplgroup=60&catcode=56C&modelcode=K&makecode=LC&grouptype=B&modelid=7074&uid=1

http://www.compnine.com/index.php?u=1&year=2003&artnbr=TX04-040&artsfx=NULL&supplgroup=60&catcode=56C&modelcode=K&makecode=LC&modelseries=200&uid=1&modelid=7074&capuid=1&majorgroup=04&grouptype=B

well I ripped out the tranny last night and found the converter to be in good shape. No broken welds and the inside of the bell housing is clean. Except the very bottem where it was leaking from the converter seal.

How do I get the old seal out without damaging the shaft? And how far do you press in the new seal or will it stop when it seats?

what seal is it in those diagrams?

well getting the seal out was no problem, but getting the new one in didn't go so well. I damaged the new one when putting it in.

Anyone know an eaiser way to get the input shaft seal in and seated with the shaft still in place? ( besides the right way by removing the shaft):rolleyes:

Also how far should the seal set in?

Thanks again for your replies.

well getting the seal out was no problem, but getting the new one in didn't go so well. I damaged the new one when putting it in.

Anyone know an eaiser way to get the input shaft seal in and seated with the shaft still in place? ( besides the right way by removing the shaft):rolleyes:

Also how far should the seal set in?

Thanks again for your replies.

There's a tool for it that's like a big piece of pipe. Install the seal flush to .020" below the face of the pump.