97 12 valve, while driveing in 4x4 it slipes out & the 4x4 light goes out but it comes back on. put a vacume gague on the lines where they go on the cad. it holds pressure. it has about 30in. but when sitting ideling the light doesent even flicker. it seems to slipe out when under a little pressure. anyone with any ideas.

 

sounds like a fork out of adjustment or worn out

 

is this the fork in the transfercase, or the front axel.

 

fork on the front axle,had a problem with mine and just got rid of the vacuum set up and installed a posi-lock system, 4x4 Posi-Lok Canada , cable activted shifter work great and also give you 2wd low range

 

thats exactly what mine was doing and i replaced my u-joints in the front and she has work perfectly ever since

 

if you want the best in front axle setup you can check out EMS offroad thats who i got my lockouts from they are great people to talk to about these things AND they are way cheaper than dynatrac