95 jimmy no 4wh

i have a 1995 jimmy the 4wlow works but when trying 4wh it wont go in. If i disconnect the battery then try again sometimes it will work other times it acts like its stuck it also made a grinding sound once like it was half way in any ideas thanks:runaround:

Mine was doing the same thing. Ensure that the vacuum switch under the battery tray is functioning correctly (vacuum supply and cable is working). Also check the actuators on the transfer case as well, i.e. vacuum source, etc. Let me know. :sunglasse

Also check the linkage for proper adjustment (or is yours the push button type?) & the lube level in the Transfer Case.