My wife will be taking over my 1999 blazer automatic and we were kicking around the idea of awd and a friend suggested conv to auto trac, whats involved in a conversion?

 

Ive only done the opposite(swapped my 236 for a 233) but, Going from a 233 t-case to a 236 you'll have 3 speed sensors instead of one. You'll need a shorter driveshaft. You'd likely need the tccm to match the 236, the 4 button switch, and I would guess a couple wiring diagrams, a bunch of rolls of wire, and a while lot of time for the wiring.

End game, an AWD swap would be much simpler and more reliable.

 

Yes, like Chevyriders said a lot of work would be involved. Completely different sysem electrically. Involves having signal input from ABS, VSS several engine management signals and PCM, TCCM. If you were dead set on doing it you cold buy a donor blazer with the system and just start changing parts. Good luck.

 

so i should start calling junkyards for a bravada instead, i appreciate the responses guys thanks!

 

Youd want a set up out of a first gen bravada or first gen astro van. Second gens started using a "smart trac" transfercase which is computer controlled.

 

What does your 1999 have now? The 3-button or 4-button 4wd system.

Is not the AutoTrac system basically having a 4-button system engaged at all times with no provision for 4-lo?

 

Auto trac is the 4 button system.

Smart trac is what the second gen bravadas and astrovans have, and is computer controlled. It works almost like traction control- the percentage of power delivery between the front and rear wheels varies depending on the slip the wheel speed sensors detects.

In the first gen system you have a set amount of power delivery split(I forget the percentages) between front and rear end

 

Mine has the three button.