It started out looking like the leak was comming from the gasket, I probably over torqued all the bolts,I still had a drip. I used a degreaser and cleaned the case, then drove down the road 1/4 mile. I crawled under with a flashlight and was able to locate a small BB size hole near the top of case. I roughed up the area around hole,cleaned with accetone and smeared JB weld in the hole and around.I placed heat lamp over area to help cure.I used quick cure JB weld. This repair has held for 6 moths but I've since had two more holes occur. I think these holes were caused by porosity,the holes are all to far apart to have been caused by pump I would imagine. I'm running out of JB weld!

 

what is the year make and model ?

 

2003 chevy silverado 3/4 ton HD with 6.5 duramax and Allison trans

 

With all the holes appearing in my 03 silverado transfer case I decided to do some research and this is what I've found. GMC and Chevy 98-07 made the transfer case with a internal pump that over time rubs a hole through the rear case. Go to YouTube and put in "Hub Rub" then watch Merchant Automotive, it shows two guys From "TRUCK U " with an open transfer case and the installation of the after market Merchant automotives transfer case upgrade kit. Then Google Merchant automotive pump upgrade kit and you can purchase the upgrade kit for $99. They even have another site for instructions on installation with step by step with a photo of each step.If your rear case is ate up like mine they offer a replacement rear cover. So far I've been patching the holes with JB weld but now that I've found out about this upgrade kit I can't wait to fix it right!