450 timber jack skidder automatic transmission

[TUCKER 2005]

I have a 450 timber jack skidder with a automatic transmission it backs up in all 3 gears but pops out of gear when you go forward . I [put a new transmission pump in it did not help any ideas

[kiko]

Slack in shift cable or shifter it self not allowing complete forward engagement before shift lever hits it's stops.  With machine off shift from reverse into forward then locate where shift cable attaches to transmission control valve, you  will likely find it not detented into forward all the way.  If trans pressure drops when forward kicks out it is likely internal.

[TUCKER 2005]

could it be oil leaking by   shift spool

[thecfarm]

TUCKER 2005,just want to welcome you to the forum.

[so il logger]

Welcome to the forum, mine leaks a little oil around the shift spool. it only does when shifted from rev to fwd without using declutch. I even replaced the seals, I have the 4 speed clark. I can't help you on the other problem sorry. Kiko know's his stuff 

[kiko]

Thanks for the compliment So IL.  I just like to share what I know and increase my knowledge from people that have had different experiences than me.  If I accidentally start talking about the internal workings of a skidder in mixed company everybody develops a blank stare as it is obviously going to be a one way conversation.  This is one of the few places I can let it out. Anyway,  It is not to likely that the shift spool is bypassing, although it is theoretically possible .  Watching trans pressure is key to diagnosing transmission problems.  What does the pressure do when when it won't go forward? 
Your skidder has a 2800 Clark transmission.

[xalexjx]

does the prime pressure drop when shifting? could be the shift forks or linkage or cables wore, there is an adjustment on the end of the cables on the transmission side. Where are you located?