I did a re-build on my '01 4 door's auto transmission awhile back - when i removed the t-case from the transmission adapter I could've sworn there were only 5 bolts used to hold it on - I've been looking around and all the documentation i can find on this t-case says there are 6 holding them together

Was I delusional from too much beer and late nights after work? Could someone confirm that there are only 5 (or 6)?

I can find gaskets for both patterns online and I've crawled under my truck but i can't get a good look/feel all the way around to count them

I've tripped over an NV3500 from an early '90's pickup and seen around the forum words to the effect that GM used the same transmission (save for gearing) in the p/u's and s-10's - but this transmission has 6 bolts to mount the t-case, so now i'm running in circles on google trying to make sense of it

anyone got a definitive answer?

 

There are 6 bolts that bolt the adapter to the back of the transmission. When GM changed to the two piece case, they changed from a square 4 bolt pattern to a hexagonal 6 bolt pattern. THIS PAGE has a picture and some history.

 

6 bolts from adapter to transmission - how many for adapter to t-case?

 

The NP208/231/233/236/etc (or NV) transfer cases are all held to their adapters with 6 bolts. Have been going back MANY years.

 

interesting... well now i'm going to have to try again to see if i can get my fat fingers up there to count them, or maybe see if i can get ahold of one of those inspection camera things...

not that i don't believe you, its just i was sure i only counted 5 because i remember hunting for #6 during disassembly and never finding either it or a space for it!

 

Just to make it more confusing, on my 90 it is held on with 5. However mine are 700r4's and 231's/207's I believe.

 

I must have been looking at the full size transfer cases... The more I looked into it, the more I was finding 5 bolts.

Image of a 231 along side a BW AWD transfer case from an Astro:




I have been trying to find some of the more recent ones because I'm certain I have seen them with 6 bolts on the 2nd gens, but for now, sorry for the mis-information.

 

I managed to find the tattered remains of the gasket I removed from the transmission in my garage (i should really clean it up) - it's definitely a 5 bolt on mine

Thanks for the pic! - guess if i want a stick I'll have to go to the wrecking yard to see if they've got a 5 speed with a 5 bolt flange - or maybe the manuals are where the 6 bolts are used an the 2nd gen...

 

All of the schematics that I am finding show 6 bolts which is probably where most of the confusion comes from. GM likely used the same schematic from the full size trucks whenever possible and all of the parts shops duplicated this.

Add in the fact that Dodge used the NP233 transfer case as well and they were all 6 bolt...

 

here is a pic of a 231c... 5bolt