4x4 problems...HELP!!!

[mikekendall69]

ok i can try to explain this the best i can. when i engage 4 hi with the push button i hear it click, the light says its engaged, but when i get in the mud or something slick i get this grinding noise and all of a sudden it will engage and throw me back in my seat! then it will desengage again and the grinding is back. 4 lo does the same thing except in reverse, it will stay engaged the whole time in reverse. i have replaced vacuum lines from the transfer case and it didn't diagnose the prob.

if anybody can help i would greatly appreciate it!! thanx!

[JaVeRo]

It sounds like the cable is not getting pulled far enough by the vacuum actuator due to corrosion or the teeth in the actuator on the front axle are worn (at the opposite end of the cable).
Try reading thru this thread, your problem sounds similar. Most of the information you may need will be on the second page.

http://www.automotiveforums.com/vbul...d.php?t=671487

James

[muddog321]

Thats probably it so if a 3 button system (np233 case) the vac switch is on the drivers side of the transfer case and they do fail. If a 4 button autotrac case (np23) the vac switch is on the firewall. Either way first check all vac lines under hood drivers side from valve cover PCV area and also the one to the fender mounted reservior.

[mikekendall69]

i have looked at the three vacuum lines and one is cracked. i followed it and it goes up to the transmission dipstick and sits there. i am going to a junkyard later this weekend to see if i can find an actuator and stop by auto zone for a line. i'll let you know how it turns out ASAP

thanx for all your help, i really appreciate it!