I have been wondering is there a way I can safely stop the front axle from engaging when I select 4L? I am going to be pulling a trailer on Friday and would like to use the low gearing of low range to help with backing up an incline to an entrance. I looked under the hood and it looks like I can disconnect the electrical connectors from the vaccum solenoids. If it is possible to do it what one would I disconnect for temporary use?

 

Why not leave the 4wd in and use all four to push it backwards?

If not that just pull the front drive shaft... shouldnt be to bad..its bolted on with flanges on both ends i think

 

i would use the 4 x 4, but if you want to disconnect, how about looking at the axle vacuum cylinder and disconnect the hose at the bottom, or follow it up to the motor and pull and plug it up there. i dont know which hose it is right now.

 

I saw this on eBay and considered it to repair my broken shift diaphram mount but it is a little pricey for what you get IMO. It will do what you want though. Check it out.
4x4 Posi-Lok AXLE DISCONNECT System 97-03 Ford F150 4WD
http://cgi.ebay.com/ebaymotors/4x4-P...QQcmdZViewItem

 

The reason you want 4lo gearing but not 4 wheels turning is to make it easier to turn, when you are backing up with a trailer you will at times turn the wheels all the way and it is a PITA if they are engaged, as well as hard on the front end. That is the biggest benefit to manual hubs. The only way I can think of is finding the right fuse to pull for the vacuum pump or some other thing in the systems that you can kill.

 

I miss locking hubs just for that use.

Don't know how to do up top, but disconnecting the hoses on the axle will do what you wish. Easily done as well. Just plug to keep dirt out. I ran 2k miles without any issues of the front trying to engage. The transfer case will still engage to the drivers tire, but the spiders gears will turn freely since the pass tire is not connected.

Never thought of inserting an overide on the controller. a switch inside to disable the change and hold in 2wd setting would be slick.

 

And a heck of a lot cheaper than that cable kit!

 

I took a look under the hood and was thinking that maybe disconnecting the plugs from the solenoids to prevent the front from engaging.

I did decide to look in the owners manual and just pull the relay that controls that but it also controls other functions.

 

PM me your email address and I'll send you the schematic for the axle shift solenoids. The solenoid with the light blue plastic line is the one that engages the front axle. The pink line disengages it.

 

Since several have expressed interest in having the schematic I'll post it here.

 

I would like to thank you all for the help. I was able to disconnect the front axle and it worked wonderfully. The low range gearing helped greatly in backing the trailer up the ramp. So again a big thanks to those who helped and ncranchero for the schematic of the front axle system.

Jason.

 

So where did you end up disconnecting it? I haven't tried it yet, wondering what worked for you.

 

I just unplugged the connector on the solenoid on the right side looking from the front of the truck. It simpler terms I disconnected the one with the light blue line coming out of it.

 

Simple enough! I might have to add a dash switch for that. I miss not having locking hubs but haven't run into a problem yet. Better mod it before I do.

 

I put my vacuum motor back on yesterday and it wouldn't engage the front axle. Fords wiring/vacuum diagram I posted is wrong!! The blue line goes to the back of the actuator/motor and the pink line goes to the side with the plunger! Works great like that! Sorry for the wrong info but it was from FORD not me.