4X4 problems

[For3ver3ndeavor]

ok, so i just bought a 1990 jeep wrangler. my 4x4 didnt work when i bought it, but i was looking to tinker, so it didnt matter. i was told the vacuum switch against the firewall was bad, so i replaced that. the vacuum hose coming off of that that leads to a v-shaped plastic piece is fine. the v-shaped vacuum piece though looks broken. what is that piece called and does any have a link to some diagrams that i might b able to use to fix that

[Rodeojet52]

Originally Posted by For3ver3ndeavor

ok, so i just bought a 1990 jeep wrangler. my 4x4 didnt work when i bought it, but i was looking to tinker, so it didnt matter. i was told the vacuum switch against the firewall was bad, so i replaced that. the vacuum hose coming off of that that leads to a v-shaped plastic piece is fine. the v-shaped vacuum piece though looks broken. what is that piece called and does any have a link to some diagrams that i might b able to use to fix that

You need to narrow it down first.

Put the Jeep on 4 jack stands. Crank it up, put it in 4wd. See whats turning and what's not.

If the front driveshaft is rotating and one of the front wheels isn't, you have front actuator problems.
-You can test the actuator by removing the vacuum lines from it and blowing compressed air (about 15 psi) into either hole. If it shifts, it's good.

If the front drive shaft isn't rotating but the rear is, you have transfer case problems.
- Could be as simple as adjusting the linkage.
- Could be time for a replacement T-case

I have a 95 and the vacuum switch is on the transfer case, not the firewall.

[Ray H]

Originally Posted by Rodeojet52

I have a 95 and the vacuum switch is on the transfer case, not the firewall.

The vacuum switch for the front axle actuator is on the tcae but if its not getting vacuum, it wont switch. Pull the vacuum lines off the switch on the tcase and see if its getting vacuum. Troubleshoot the system in reverse, starting at the front axle disconnect motor and working back.