2000 Bravada AWD issues

The number one most problematic component of my Bravada over the years has been the AWD system. I have decided its time to get this system functional again even if it requires spending thousands at the dealership. I'm first going to try to tackle it on my own, but last time it didn't go so well...


At almost precisely 75,000 miles the "Service AWD" light came on and stayed on and the AWD quit working. I had an extended warranty and took it to the dealership to get repaired. My receipt (which I still have from 2002) states they replaced the actuator (ACDelco part number 12474041). Alas, the AWD worked.

At almost precisely 150,000 miles the AWD light appeared again with the same symptom. This time it was not covered under the extended warranty so I ignored it for the next 15 to 20 thousand miles. Finaly I got a wild hair to fix it, so I got on the trusty ol' automotive forums and started reading. The trouble is the bravada forums seem to be mixed with the Blazer forums and the best I can tell there are some differences in the AWD components between these vehicles. Anyway, I found someone who had the same problem as myself and I chased down an aftermarket actuator he had bought for his Bravada and I tried to install it.


The part seems easy enough to install, however, in the directions it stated something to the affect of "vehicle must be in 4 wheel drive before installing this part". It is completely beyond me how you get the vehicle into 4 wheel drive without the part that supposedly does the shifting, so I just turned the little mechanism in the new part so it would slip into place (disregarding the message stating that turning the mechanism be hand before installing would damage the part). The result is the part never worked correctly. The "Service AWD light quit coming on after installing the new aftermarket actuator, but the AWD never did work quite right. It will shift into AWD from time to time, but never reliably enough to have any sense of confidence when driving the Bravada on wet roads.

My theories are:

- The aftermarket part I bought was defective from the start
- By not following the directions and not somehow shifting the transfer case into 4 wheel drive before installing the actuator, I defeated the new part.
- There is another issue going on

My questions:

- Do any of you know anything about this system and how to diagnose it when the dash light isn't coming on?
- Do any of you know how to shift the transfer case into 4 wheel drive when the actuator is not installed?
- Do any of you have any other input?



Thanks,
Chadwick

I'm sorry but because I haven't worked on the '98 & later "smartrac", all I can offer is to get a Factory Service Manual before starting any work. I didn't see one on eBay today but I have seen them in the past.

I actually have the shop manual for this vehicle. It consists of three large books and combined they are at least six inches thick. They have been very helpful for many projects with this vehicle, but the section about the AWD troubleshooting might as well be written in Japanese. For some reason the whole thing is very elusive to me. It seems like you have to already have a substantial core knowledge to be able to understand the manual about the AWD.