So I have a 1999 f350 super duty 7.3 diesle 4x4 6 speed and it clunks when letting the clutch out when up shifting. I have never had this sound from other vehicles but wondering if maybe its normal on the super duty with all the heavy duty clutching system ? when I down shift it does not make any abnormal sounds. Also when letting the clutch out into gear is sounds like a pretty loud clutch plate but never slips or acts like anything is wrong. I just want to know if these trucks are just extra noisy or not and have nothing to worry about. Thanks ..Steve

 

I just purchased a 2000 f 450 7.3 with 6 speed zf. Mine is noisy as hell in every way imaginable like you described.i would like to know the same thing. The dealer told me this is normal. I also get alot of gear clash noise. Maybe someone a little more knowledgable can give some input?

 

Lube your slip joint!

 

Been lubed a week ago. Driveshaft is tight. Clunk is un clutch?

 

Yours sounds like a TO bearing.

 

I think these trannys are just noisy. Might have a problems but even new they are noisy.

 

+1 on the throw-out bearing.

 

That is probally true, but these transmissions are iherently loud right from the factory

 

Ok Good to know mine is not the only noisy truck lol ..But how and what do you use to lube the slip joints ? I may try it even tho it seems like this noise is normal on these trucks. Also when you let the clutch out for the gear it sounds mostly like swirling metal on metal for a short bit untill its engaged fully, thats the only way I can describe it..as well as the clunk when upshifting Thanks for the replys ..Steve

 

Yoy have to disassemble the slip joint (no grease fitting, unlike chevy) ford has a special grease to use I believe. You are NOT the only one to have a noisy zf6. They all sound like meat grinders!

 

Oh Ok so it can take a while your telling me haha...Ok so I am starting to think its normal anyways for these 6 speed zf's ...I will have to grease the slip joint anyways just for the hell of it..I will have to find pics somewhere as I have no idea what im looking for to take off lol

 

It is where the two driveshafts connect by the carrier bearing. One end is splined and fits into the other. Dealer did mine under warranty.