Good evening.  I have an early 60s d4d.  It is forestry model with manual transmission with forward reverse shifter.  Has wet clutch.  We were using it yesterday and all fine and on shifting from reverse to forward it just quit pulling at all.  No movement in any gear or forward or reverse.  Pulled clutch cover abd input shaft to tranny is turning.  It will make slight gear noise on changing gears ans it feels as if the fork is moving the forward reverse slide gear.  There was no pop or any noises when it happened.  Any ideas appreciated.  My next move was to pull tranny cover. 

Brook Bearden.  
63 d4d
55 d2 5u

Sounds like something wrong with the gear shift interlock mechanism.

Sounds like you need a clutch adjustment. May be enough to turn transmission input shaft but not enough to handle load.

thanks to all for your replies. THe clutch output is good for sure as we pulle cover and watched as we ran it. I am goign to pull cover of transnmission and ill see what we find. I am suspicious of the sleeve from clutch to tansmission input as well. thansk again.

well was as expected. the keyway ahad worked its way out of the coupling from tranny to clutch. THe coupling os worn pretty good so it is moving on going from forward to reverse. I was thinking of milling it out to the next size keyway and then cutting the other half of the keyway back to original size for the tranny slot. May just put a new keyway and roll on for now. Probably last a long time like it is. Old keyway very worn from walking back side to side. THanks for all the replies