L3600 GST very slow at shifting gears

[Billstown]

I've got a 1996 L3600 (1,500 hrs.) with a GST transmission. I have started having a little trouble shifting between gears. Shuttle shift works great but shifting between gears is a different story. Glide shift lever moves easily with no resistance at all. Problem is that it takes 4 to 5 seconds to actually shift gears. During this time the tractor is free wheeling. On a hill, it will actually start rolling down the hill backward before the transmission finds the next gear. I'm also getting a sligtht grinding noise between some of the gears. Most of the grinding takes place when shifting from 3ed to 4th gear. Transmission has been regularly serviced so that should be the problem. Any info. or suggestions are greatly appreciated

 

[North Idaho Wolfman]

It sounds like you have either a clutch seal failure or a shift valve issue.

How are your skills as a mechanic?
The WSM will help with testing and tear down, but you will need a very high mechanical knowledge to fix it.