Hi all, long story short, did some debugging to why my 4 wheel drive wouldn't engage. Not the front differential actuator. Put vehicle on stands, engaged manual (not electric) 4wd floor shifter, but the front drive shaft doesn't spin. I'm thinking my transfer case is out, but before I go to that extreme, I want to see if anyone has other insights?

Thanks in advance.

Truck has 99K on it.

Tim

 

For those that have already viewed once – sorry was in a hurry last night on my original post, wanted to clarify and provide a little more detail.

Last year my truck started having some abnormal noises when engaging into 4wd: a clicking when turning corners, and a bit of a grinding noise as it engaged the transfer case?

I made it through the winter last year, but want to beat it this year. When I had it in for an oil change, I had them give me an estimate on the problems. They didn’t put much effort into it and thought it was the front differential actuator, but I’ve confirmed that wasn’t the issue: The front actuator engages: I can hear the effect of having the two wheels tied together, and I pulled it and tested it, plus when I have it in 4wd the two front wheels are tied together (on stands) and not tied together when not in 4wd.

I put the truck up on 4 stands and engaged 4wd. The front shaft doesn’t engage and spin when in 4wd.

Truck is a 96 K1500, with 241C transfer case, has 99K on it (mild driving, very very limited 4wd). Manual transfer shift, not electric.

I'm thinking my transfer case is out, but before I go to that extreme, I want to see if anyone has other insights?


I noticed two other items in my research so far: a vacuum switch, and an electrical switch, both on the xfer case, but I suspect the electrical switch is for electric transfer case models.

Thanks in advance.

Tim

 

wow - more than a little surprised that no one has responded by now! wanted to log in and provide an update, for any future visitors that may benefit.

Clicking during turning corners was due to a bad u-joint on the front drive shaft. did the loaner tool program and advanced auto parts for the press tool, worked great. Simple and inexpensive fix.

The lack of engagement obviously didn't improve with the new u-joints (I was hoping they were a related issue until I found it was just the u-joint for the clicking sound). After I got the u-joints replaced, I could shift to 4 low probably 12 times and NOT have it engage the front drive shaft. I decided to do the manual shift to 4 low. and it started engaging the front shaft. I guess working this back and forth release something that was stuck? I probably went all the way forward to 4 low and all the way back to 4 high maybe a few times, less than 5. I've probably shifted to 4 high 30 times since then, and had 100% engagement! I also swapped out my fluid (but I did this before the u-joints, so this wasn't the fix, but it may have helped).

Hope this helps someone!