NNBS transfer case issues please help

[fortplainman]

so long story short a little more than 2 years ago i had my transfer case go on me. every time i put any power in reverse it would seem to drop out of gear and have a nasty grinding noise. a snap ring broke on the shaft and essencially caused a shitload of shrapnel in it and i had it replaced with a gm remanufactured unit.

so fast forward to the past couple weeks, had the same thing happen from what the tech told me. i dont care about fixing it, that isnt the issue. my issue is if anyone has heard anything like this problem in other nnbs trucks and if they had a lift/tires/tune/gears etc. i have looked around a couple forums and have found nothing. i just dont see what could cause a second transfer case to blow up on me or how/what can be done to strengthen so so called snapring from breaking.

 

[1BADSS396]

What is a NNBS?

 

[daddy]

Assuming you mean the GMT900, I don't recall this being a common issue.

Did the rebuild have a warranty?

 

[fortplainman]

The rebuild only had a 18 month 100k warranty and it's 27 months old and 20k miles

FFB device

 

[daddy]

Have you spoken with them yet?

 

[fortplainman]

Working on it

FFB device

 

[Nick The Great]

What is a NNBS?

It's the generation of trucks before the NNNBS. Duh

 

[PenguinLTZ]

Working on it

FFB device

Man, that is crazy. I have not heard of this issue.

Let us know what they say.

 

[fortplainman]

found a service bulliten on gmt900 trucks made before april of 2008. snap ring on the rear output shaft was a different hardness rating that they changed and could break. causes grinding/howling/transfer case disengaging under load which my truck would do.

 

[Darkanion]

found a service bulliten on gmt900 trucks made before april of 2008. snap ring on the rear output shaft was a different hardness rating that they changed and could break. causes grinding/howling/transfer case disengaging under load which my truck would do.

Hopefully that's all that's wrong with it!