Hello,

I am new to the forum, thanks already for all the helpful info. I am looking at buying a used f150, and test drove a 2002 f150 xlt 4x4 with the 4.6. Fairly decent shape overall, but during testdrive there was a clunk coming from frontend while accelerating in 4 wheel drive. When in 2wd, all was quiet. Put it back in 4x4, accelerate from a stop somewhat aggressively and again there was a clunk that was heard a couple times while accelerating. Something with transfer case or front shafts?

 

it normally makes a clunking sound when you engage it and accelerate right away or while driving a very low speeds. if its done while driving at a decent speed or starts to clunk awhile after it being engaged i would get it checked out. Maybe thats not normal but i have a brand new truck and that what it does.

 

it is not the normal noise when engaging 4wd, it is while accelerating up to higher speeds in 4wd. i don't think it is a normal noise. It is only present while accelerating somewhat aggressively while in 4wd.

 

thanks for the reply though

 

Possible thoughts are the u-joints on the front drive shaft are binding from lack of use.

 

ok, in your experience, will these work loose, or will they need to be replaced? Thanks for the reply.

 

I would replace the u joints did on mine. waited to long the first time broke the yokes

 

I have been to a local 4-wheel shop about three times to try and remedy this problem.

My 06 FX4 makes this loud clunking noise when 4 high or low is engaged and agressively accelerate. I first noticed it while going through a sand pit. Now it does it when make a launch from a dead stop in 4 wheel.

The shop's first dianogsis was that the pinion gear was broken. So paid them $550 to change it out, but still same problem.

Noise is difinetly coming from front end somewhere.

The next thing that the shop did was to remove two bracess that mount up under the swaybar(these bars come with the fabtech 6" liftkit) BUT, STILL same darn noise.

I took it back again, they checked the CV's, transfer case, driveshafts, and have found nothing wrong.

This truck still has a waranty on it, but because of the lift kit the Ford dealership has refused service.

I'm starting too feel dazed and confused by this whole ordeal. I need help