ak_cowboy

I have a 2007 F150 XLT 4x4 with a manual transfer-case. Recently (last 6 weeks) if I engage 4wd while moving, then try to disengage while moving my passenger side doesn't release. I can feel it pulling to the right and hear it whining in the cab. I have to come to a complete stop, re-engage 4wd, drive for a little ways. Complete stop again, disengage 4wd, and sometimes spin the rear tires to get 2wd back.
Any ideas on what's going on? Do I even have vacuum lines to worry about? Are the hubs engaged by centripetal force?

ford4wd08

you have a vaccum line to pull the hubs out from being locked, i would get a vaccum test and then see if its the soleniod on the firewall not having a good vaccum, if its not that i would check to see if you have a hole or crack in your hub actuator, not very hard to fix just takes time....

ak_cowboy

Do you think cold would have an impact on the lines too? Its been -20F here for awhile...

ford4wd08

you cold have water frozen in a line, i would get it checked and get your lines blown out

ak_cowboy

Alright, I'll have to do that once it warms up. I used it today, but made sure I was at a complete stop engaging and disengaging, and it worked fine.

driver444

My truck OCCASIONALLY does the exact same thing. I even posted something about it a while back. It seems like the faster you go when you engage it, the longer it stays engaged when you put in back in 2wd. That whining you hear is your spider gears in the differential. As the passenger side shaft is spinning forward, the other side is spinning the other way.

Anyway, took it to the dealer, they did all the vaccuum testing, said nothings wrong. The mechanic did give me a little insight though. This may be BS, but it kinda makes sense. He said if it's extremely cold out, if you go back to 2 wheel drive, and one hub unlocks before the other, and is allowed to free-wheel, the viscosity of the gear oil in the differential will keep enough resistance on the locked shaft where the hub won't release right away. I suppose that could happen, and it would explain why it unlocks almost as soon as I stop.

I do always TRY to stop, or slow way down before I engage the 4wd though. It's just a good idea, shift-on-the-fly or not.

ak_cowboy

Ok, I figured the whine was the gears. Is there anyway to upgrade the vacuum lines to something stronger? like braided or stainless or something?