clark transmission

[350 cummins]

my clark 662 shifts fine when cold but after it warms up it is slow to shift from first to second, works fine after it shifts to second gear just slow to shift, anyone have any ideas. thank you

[oldseabee]

Put a gauge in the clutch pressure test port and hang it in the cab,  watch the gauge during the first to second shift. and back to first. If you have a gearmatic winch it should not drop below 180 PSI, if you have a Clark winch it should not go below 240 PSI. If it drops below the clutch pressures that I mentioned the clutch pressure regulating valve will cut off flow to the converter and feel like a slow shift, this can be caused by a weak charge pump or a clogged suction screen in the trans or the suction line is sucking air some place, the other check is to read the clutch pressures in all gears with hot oil and if one is more then 5 PSI below the rest that indicates high leakage in that clutch circuit. Again any time clutch pressure drops below spec, oil will be cut off to the converter

[350 cummins]

thanks for the info oldseabee, checked pressures everything was good, took it out yesterday pulled wood all day and it shifted fine, hope it keeps working like it did yesterday