Lately I've been hearing a metal rattling sound when I first crank up. I've read before about a sound that's like a coffee can full of marbles and guessing that's it. I also get a soft bump that can be felt every time i start moving from a full stop. It's almost like a shift but happens within the first couple of inches from take off, like something in the drive train is loose and catching up.

Question is am I looking at only a bad torque converter or worse. All other tranny operations seem normal. No slipping, no unusual shifts, or over heating.

Also if it's only a torque converter any suggestions on a reasonably priced but strong enough TC. Only towing I ever do is a 3000lb boat and occasionally a 4 to 5K tractor/trailer/ implements rig. If when I ever get tunes they will be mild.

TIA,

 

The bump is a dry slip joint in the drive shaft. Ford dealers have a special grease that lasts longer in the slip joint than anything else you'll find.

 

Thanks Mark,
I had heard of a clunk discussed before associated with the slip joint. I figured since I wasn't hearing anything it may be tranny related.

Off to look up drive shaft maintenance

 

So I went by the Ford place today to get the blue grease and the parts guy says "they've changed the color again. the latest and greatest is white". He walks in the back and comes out with a kit. It has a pack of grease and a band clamp.

Look right? I asked him if this was for the F250 Superduty. He says yep, it's for all of them.

Guess it's not "for all of them" cause the clamp didn't fit. too small for one end and too large for the other. No big deal, wasn't planning on using a metal crimp on anyway. I used the grease but will plan on doing it again soon if not the right stuff.

$16 for the kit. Probably could have gotten a whole tube of PTFE grease anywhere for $6 or $7 but figured if it only has to be done every couple of 100K miles why not use the recommended OEM.

 

Oh yeah, and thank you Mark. No more bump.