Hello All

This will teach me not to play with things LOL This all started this afternoon, I went out and removed the front wheels to put some disc brake goop on the back of the pads to quiet them down. I had the left front wheel off and twisted the rotor to make sure everything was ok. I noticed that the front driveshaft was spinning. I didn't think that it was supposed to do this. After further investigation I discovered the the front axle was locked in. The actuator cable was frozen. I eventually got it unstuck. Now heres the problem. It won't release when the engine is running. It doesn't matter if its in 4H or 2H, it still has vacuum at the acuator. What I need to know is where this vacuum comes from. I traced it back to the transfer case but GM put all the hoses on top of the case so they are nicely out of reach. If anyone has any ideas please let me know.. I have it plugged off right now so it won't engage the front diff. Thanks

 

The transfer case switch is where all of those vacuum lines run to, on top of the transfer case.

 

Do you have a vacuum diagram of that system? I am correct in assuming that the front driveshaft is NOT supposed to spin in 2WD mode? I'll see tommorow if I can get to that vacuum switch. Where does that atmosphere vent come out at? Thanks for the info

Boy am I getting an education on these things in a hurry!!!

 

You are correct. For the NP233/NV233, the front axle should be free to rotate when in 2HI.

About the vacuum diagram, I am sure I have posted it in the past...

 

I have the one of the front axle but I was looking for the diagram of the transfer case as I think that this is where its going to be. It seems like maybe there is some trash in that vacuum switch. Now the fun part is going to be getting to it without having to drop the T Case. Thanks for all the help so far.

 

You definitely do not have to drop the transfer case to get it out. It is accessible over the front driveshaft. I believe it is either a 7/8" hex or a 15/16" hex... Can't remember for sure though.

And I have posted an image of your transfer case that I grabbed off of eBay at one point or another before showing the location of the vacuum switch... Let me see if I can locate that for you.

Here ya go:

 

Thanks for the pic. That helps a lot. I will go and see if I can get it off and get it fixed.

 

I got up this morning and removed the T Case vacuum switch from the top of the T Case and it was stuck. I went down to autozone and got a new one and put it in and now everything works as it should. Thanks

 

Glad to help! Also glad that you were able to get it all fixed up!