4x4 wont engage

akf250 · Nov 11, 2011

4x4 wont engage the front wheels. My transfer case rotates when engaged so im thinking its a vaccum leak from the dual vaccum control module to the hubs? Does this sounds right? Anyone else have any problems with there 4x4? this is the second time its gone out in 2 years

BFT · Nov 11, 2011

do you hear the pump running?

907DAVE · Nov 11, 2011

Check the vacuum lines where they connect to the frame brackets on both sides (in the wheel wells). Pretty common for them to break there.

Spastik monkey · Nov 12, 2011

could also be the actuator inside the tcase

907DAVE · Nov 12, 2011

Not if the drive line is turning.

08murderedout · Nov 15, 2011

I just bought my 3rd 6.4. Its a king ranch and has the manual 4wd lever on the floor lol. The guy said he ordered like that. i didnt even know they still put those in super dutys

B.Warning · Nov 25, 2011

Check the vacuum lines on the front axel. I've had corn stalks rip mine in half several times.

TxFireman1972 · Nov 25, 2011

If you have your AC running, and switch it to 4wd does the AC go to defrost? If it does, it's from a vacuum leak. Either a hose off somewhere or the solenoid is bad. My 4wd solenoid (can't remember the name) was bad. Was about $50 at the dealer. Mine was on the pass side fenderwell.

EvilTwins · Nov 25, 2011

I don't know if this will help but going to put it up anyway. Im currently having an issue with the 4x4 system and will share my info if it helps. Its a PDF from the service manual. The only hang up is, the info is from Jan of 2008 and has not been updated.

https://files.me.com/dgmcbride/ch95gl