Okay I have a 1998 GMC Jimmy SLT 4.3 vin w, 4l60e tranny, with nv233 tcase. 3 button 4wd (doesnt have auto 4wd)

This just started the other day. I put it in 4hi the other day and it was fine. Went to take it out of 4hi and it didnt want to go back to 2wd. It took a few minutes and I got it back in 2wd.

Now Im driving down the road (2hi lit) went to put it in 4hi and nothing happend no lights flashed or anything. So while going slow I put it in neutral hit 4hi again and nothing. So I came to a stop put it in neutral hit 4hi then 4hi and 4lo flashed for a second and it went back to 2wd. Didnt hear any noise at all. I put it in park hit 4hi and nothing. Will only do it when in neutral and stopped.

I checked all vacumn lines found a small leak and fixed it but same issue. I believe its possibly the Transfer Case Shift Motor? Can anyone verify this for me before I work on it? Also I know there was a detailed thread on here on how to change the shift motor can anyone link me up or tell me how its done.

 

Check out these threads:
4x4 No Worky.... Maybe this will help....
OBD2 NV233 Diagnostics

 

My 96 did the same thing but stuck in 4 hi. Turns out the 4wd fuse was blown. 20 amp, upper left area of the fuse panel. On mine the actuation canister for the front axle is under the battery tray. Reach under there if you can and see if it is compressed (4wd) or relaxed (2wd).

 

Another thought- if the canister is in the relaxed position you could have a vacuum leak or vac hose disconnected.