a question of slipping

[Auto]

I'm driving up a steep snow covered mountain road yesterday with 4wd engaged (Overdrive off). I heard a "thunk" and suddenly felt the ass end of the truck slide out (it had slipped back to 2wd) I let my foot off the gas, regained control of the truck and started to slowly accelerate again. The traction had returned (4wd) and everything was fine until another 500m up the road the same "thunk" 2wd slip happened. This event happened several times but always would re-engage 4wd.

What's going on here?

2005 XLT
4L V6

 

[dhiller11]

its a chain in your transfer case aparently thats what ford tells me
happened to me last year bout this time and they replaced it and now it happens again yesterday half way up a 15% grade hill climb not fun

 

[Auto]

update

That's exactly what Ford is telling me, They expect the job to take 6.9hrs plus parts. Sounds like I'm going to search for someone cheaper to rip my transfer case apart.

Dealership labour is $$$

 

[85_Ranger4x4]

You might try a junkyard one.

They are not common to go bad, and it is fairly easy to just unbolt the old one and bolt in the new one. Great time to switch to manual if you want.

 

[feellnfroggy]

chain? I thought it was a differential style transfer case on the live axle vehicles. Isnt that what allows it to shift in and out of 4 wheel at speeds higher than 20mph? I would read up some more on that. I may be wrong, but it would be good to check. A manual transfer case conversion sounds real good about now.

 

[hondaxr650]

chain? I thought it was a differential style transfer case on the live axle vehicles. Isnt that what allows it to shift in and out of 4 wheel at speeds higher than 20mph? I would read up some more on that. I may be wrong, but it would be good to check. A manual transfer case conversion sounds real good about now.

Nope. Same old 13-54. The live axle setup keeps the front driveshaft spinning at the same speed as the rear, so shifting into 4hi at higher speeds is no problem.