I have a 98 f150 4wd with manual shift on floor (msof) and the 4wd will not engage. I've done research and I've learned quite a bit but still have an issue. In All the research I've done I have learned about the vacuum lines and the way the t-case and lines work together, but I have not found anything about two electrical lines running to my hubs on both sides up front. Does the 4wd engage/disengage at three points? I know the manual shift is for the t-case and the vacuum lines are for the diaphragm at the front differential. But what are those electric lines? Is that for electric hubs or for something totally different that has nothing to do with 4wd? I've looked and found nothing on these wires going to my hub. The wires on the passenger side are completely severed and I will replace them to make the connection again, but I just don't even know what they are for. Thanks for reading and for the help.

 

Those are wheel speed sensors. They have nothing to do with your 4x4 engagement. Your system has 3 main components. 2 vacuum solenoids on the passenger firewall and a vacuum actuator on the axle. Have someone shift it into 4x4 while you watch the actuator to see if the rod moves properly. If it does, the shift fork located inside the axle may be broken or severely worn. If the actuator doesn't move, you probably have a vacuum leak. Start checking the lines & connections for leaks.

I've said this a thousand times on here, but I always recommend getting rid of the vacuum system and installing a cable lock. It's mechanical and fool proof. Alloy USA part# 450750 is what I have. They're on ebay as cheap as $110.99 and worth every penny.

 

This is awesome. Any reason this wouldn't work on a truck with the dashboard switch? I've always converted to manual hubs on my Toyotas, if this is an in cab equivalent that's even better!

 

Yes. It will work with either system. You have a **** mounted under the driver side dash that you pull. It just bypasses the vacuum system that engages the front axle. Took me maybe 45 minutes to install.

 

Fantastic. I don't care how many times you said it before, thanks for saying it again. 2low here I come!

 

Haha. No problem man. Glad I could help.

 

"I've said this a thousand times on here, but I always recommend getting rid of the vacuum system and installing a cable lock. It's mechanical and fool proof. Alloy USA part# 450750 is what I have. They're on ebay as cheap as $110.99 and worth every penny."

When I was searching and learning about the vacuum lines and solenoids I had also read about installing the manual cable. I'm pretty sure that's the route I'm going to go. I am no mechanic and honestly not very good with vehicles, but I do all repairs and maintenance on my own so I can learn though experience. I was just curious about those wires because I am unfamiliar and they were the only thing I noticed out of place after a quick look over before work. Thank you for your reply. It's greatly appreciated

 

Your very welcome