pinhole leak in transfer case

:newbie: I am a female entering this, so bear with me. Has anyone had problem with pinhole leak in the transfer case? We just had to replace the transfer case in our '04 Silverado 1500. When they diagnosed the problem, they saw no leaks but there was no oil left in the transfer case. At first, the ext. warranty co. was going to deny it. After a week long battle, when the mechanic got the new transfer case in, he filled the old one with fluid and found a pinhole leak. Apparently, something inside had rubbed a hole in it. I have heard from several other independent mechanics that GM has a problem with this. The ext. warranty company is finally agreeing to pay the bill. The mechanic that fixed it stated that this will probably happen again down the road. Of course, GM is not acknowledging a problem. Therefore, I was wondering if there are other cases out there. Please let me know and I am trying to pursue further action so I will not have to pay a $2000 bill down the road.

Actually with a pin hole ( and this is common with aluminum ) all you really need is a product such as JB metal weld to seal it and a can of brake cleaner to clean the aluminum of oil and greaseprior to applying it. $10 dollar fix compared to $2000 fix and you can do it yourself.