Recently (as of a couple of days ago) whenever I put my truck into 4WD it makes a 'clunk!' sound. The truck is a '99 F-150 4WD with the towing package. Also, earlier in the year I accidently left it in 4 low when I turned it off, and when I starte it up and drove it the 4WD disengaged with a clunk too. could that have been the cause of the current problem?

 

I don't own and have never owned a 4wd-- but I would assume there is a ujoint connecting the front transfer case to the transmission. A bad ujoint makes a clunk when it goes in/out of gear, so I'd check that first.

 

I think it is normal for things to clunk a little when engaged, unless it is a super obnoxious clunking.

My 99 would slam pretty good when engaged into low range. My 02 doesn't, but it wouldn't concern me if it started.

 

When shifting into 4x4 make sure the front wheels are turning at the same speed as the rear. So if your rears are spinning and the front are not they are not at the same speed and it will clunk when engaging 4x4. If you are moving when shifting into 4Lo it could clunk.

JMC

 

JMC wrote: to use a very apt phrase; D'OH!

Thats what it was all along. I just noticed it. grr.........