I just bought a 2006 F150 SuperCrew 4x4

When I test drove it, all seemed ok, but now, 2 days later,
if I switch to 4 Hi on the fly, maybe 80 km/Hr, it makes a
buzzing noise, almost like static on a radio, then when you stop,
it engages the 4x4, I heard a slight clunk as I stopped, then
the 4x4 was engaged.

Anyone have an idea what is up, I bought it at a Ford Dealer,
so next week I'll be talking with them, but I would like to know
what is up before hand.


Thanks....

 

Just curious when you shifted into 4 wheel drive when you were driving did you let off the gas at all. It might be cause of that. But im not sure. I know when ever I put it in Im either stopped expecially 4 LO or when I want 4 HI and Im driving I left of the gas and you will hear it click in then continue driving. But im not a mechanic either.

 

LOL looks like I am having the same problem... but I used search LOL

https://www.ford-trucks.com/forums/7...ing-noise.html

 

Mine, 06' FX4, had somewhat the same noise over the winter. It was a rattling/chattering noise that came from under the truck and was associated with 4 wheel drive.

I ran it through the dealer and there's a TSB on a vacuum actuated relay the controls the 4WD lock in/out.

Give it a shot.