664b Clark Ranger Skidder having problems with the winch.

[delimberboy]

I have a 664b Clark Ranger Skidder and I have been having problems with the winch when you first start working in the morning for about 30 mins the winch works great until the machine startes warming up on about the second twitch the winch will no come out when its released so i have to push the fuel some to increase the rpms then it releases and works great but you have to hold the fuel the whole time someone is pulling out the mainline. Does anyone know what is wrong or how to fix it ? Thanks

[treeslayer2003]

do you have a pressure gauge for the trans? if not you need to check the charge pump pressure, should be at least 200 but 240-250 would be best. i am assuming you have a clark winch and not a gearmatic.

[Maine logger88]

I used a 666b once a few years back that was like that and like treeslayer said it was the charge pump. Makes it real hard hooking alone where Clark's don't have a hand throttle. The 664C I rented last fall I would occasionally need to idle it up for just a second to release then it was fine from there

[rockwall]

Oldseabee should chime in and help you diagnose your problem. I think you will need a pressure gauge though.

[rockwall]

In the meantime check out this old thread about my Clark winch problems.
https://forestryforum.com/board/index.php/topic,55939.0.html

[treeslayer2003]

one word of warning, do not figure out a way to have the engine turning up and get off the skidder, i have seen them jump in gear. also be sure the range lever is in neutral, some times they work better that way and less likely both levers will fall in gear.

[oldseabee]

Inside the drum there is a large clutch pack that locks the drum to the input. This drum clutch is spring loaded, when you need to freespool to pull the cable out or drop the drag transmission clutch pressure is applied to the drum clutch to release the spring pressure, the Clark winch requires 240 to 280 PSI to fullly release the drum clutch so you can freespool. In the morning the oil is cold and will give you more pressure then when it heats up. Treeslayer is right you need to check your clutch pressure with hot oil and low idle. Low pressure can have several causes, charge pump, clogged suction screen in the bottom of the trans., or the clutch pressure regulator valve on the side of the convertor (there are two different regulator valves that look the same, the other is set at 180 to 220 PSI, difference is the internal springs. Some times a used regulator valve has been put on but is the wrong pressure. Has this valve or the convertor been replaced recently? There is possibility that seals on the drum clutch piston are leaking, when you check clultch pressures compare the trans pressure to the freespool pressure, they should all be within 5 PSI of each other, check with trans in neutral, you will see the pressure in one of the speed clutches, engage and disengage the free spool to see if you get a drop in pressure at the freespool position, if so problem is not charge pump or regulator valve but probably in the freespool clutch piston or shaft seals.

[treeslayer2003]

glad to see you seabee! i try to help these boys but your the man on these clarks. wish i knew you years ago.......Mr. Whaley was a big help to me, i miss him.

[oldseabee]

Just a word of warning, before you attempt to work on this winch get a manual or at least ask us, those springs in the freespool clutch will get you if you just start undoing bolts on the side of the winch, undo 4 bolts and put in 1 inch longer bolts, then back the rest off, keep adding longer bolts until the spring pressure is releaved.  Mark the position of the bolts in relation to the clutch plates so they are installed correctly.