So the transfer case on the 2002 AWD Denali just blew. I took it to my mechanic and he seemed to think that the cause of the failure may have been due to the regearing of the truck when I had it lowered. I went from lifted with 4.56s front and back to lowered 5/7 with 3.73 front and back. Keep in mind, this was about 8 months ago and I have driven the truck approximately 8000 miles since the re-gear and I got regeared at a very reputable drivetrain shop here in socal.

WTF? If the front and rear had different gear ratios, how the F could I drive it for 8000 miles? Wouldn't it just lock up immediately since it's AWD? Am I missing something here. I even asked my mechanic straight out - "Could I drive the truck with completely different gear ratios in the front and back for 8000 miles?" He said I could but that's probably why my transfer case finally gave out.
Don't know much about transfer cases, but could this even be possible? what are some common causes of transfer case failures? BTW the denali is now lowered 5/7 on 24's. I've been going to this shop for the past 4 years and they've always seemed to do good work in a timely and reasonably priced manner. After this, I may consider changing shops. Any help is appreciated. Thanks.

 

It would bind instantly with different ratios. And if it would have even moved an inch, there would have been a drive shaft laying on the ground somewhere or a exploded front 8.25 IFS diff.


As for failure....the oil pumps in the 246 case (if thats what you have) are notorious for going out

 

my 02 denali has the nvg 149 tcase in it, but mines a sierra so I dont know if the yukons were different