NEWB, 4wd inop

[knowhimwell]

I am new to PSD and have had this truck a month. I have had chevy and dodge diesels, but this is my first Ford. I really like the truck, but need to get the issues fixed if Im gonna keep it.

OK, on to the issue. My truck is a 99 F350 4wd with twist knob 4wd. The front driveshaft turns no mater what position the knob is in, the vacuum hoses on the hubs are dryrotted, so I engaged the factory hubs manually, then disengaged them. Neither way causes the 4wd to engage. Truck only has 478k miles.

I have looked around on the forums, but have been unable to find what I need. Thanks for your help.

I have some other issues as well, but will be posting them in the appropriate place.

[jesilvas]

Not too sure on the 4wd, since I don't have it.
I know that the hubs are vacuum controlled, so you'd have to fix those hoses to have the hubs auto engage.

[knowhimwell]

Im pretty sure the factory locking hubs is a failsafe in case the air lockers fail.

[jesilvas]

I'm saying that they are vacuum operated, with a manual option. With dry rotted lines, they won't auto engage.
If the front drive shaft is turning, your 4wd should be engaged.

[knowhimwell]

I understand about the auto-engage. I think the locking hubs are supposed to override the problematic vaccuum hubs, correct?

[jesilvas]

Oh, I se what you're saying. Yea, you're right.

[knowhimwell]

disappointed to the amount of response. Sold the truck today. May be back, not sure.

[jesilvas]

Just happens that way sometimes.
You sold it? Hope it wasn't cause the 4wd was having issues.

[knowhimwell]

NOPE, It had a few issues. I will have another PSD, just not now. I was hoping to get the issues fixed and get a lil more loot for it. Oh Well.