Clark 3 speed issue

[Mainewoods0325]

I have a tj 450 with a 3 speed clark. When the transmission is cold it slips in 2nd gear. First gear doesn't slip at all. When the transmission warms up 2nd gear doesn't slip at all and runs like it should. All fluids and filters have been changed. Any ideas what the problem is?  Thanks in advance! 

[mike_belben]

I would guess leakage in the control section from cold clearance space that tightens up with thermal expansion.  


That or what you perceive as slippage may actually be a 1st gear hanging shift that drags 1st while 2nd is applied.  My forklift does that cold and you can really feel when 1st lets go and 2nd gets full traction.  It feels like a 'slip'