My Brother has a 2005 Tahoe with about 123,000 miles and he tows (about a 5000lbs trailer) with it. The transmission (pretty sure a 4L60e) is starting to make some bad whining noises - shocking, I know. I've dealt with many 2wd 4L60e transmissions before, but this will be the first undertaking of a 4wd 4L60e vehicle. I'm just pulling the trans out, so that I can take it to a local trans shop for repair, then reinstalling it. So it's just a swap. Is there anything in particular I should know or look out for, being that this is a 4wd vehicle? I understand I'll have to deal with the transfer case and an additional driveshaft, but I'd rather not run into any unpleasant surprises while working on a vehicle my Brother drives when taking his family camping. Thanks in advance.