Author Topic: clark winch (Read 652 times)

rockwall · « **on:** February 01, 2012, 07:46:50 am »

I have a 1977 clark ranger 664 B. It is a fantastic machine. The other day at the end of the day, I noticed a loss of power coming up a grade with light twitch. When I got to the yard and released the winch, it dropped the twitch, I hooked up chokers ,got on skidder and next thing I know, the winch had pulled in the cable and wrapped around the drum. I pulled that out but it would pull it in again even in free spool. I had to shut machine off to stop it. How can I check what's going on ? I had noticed the day before when I first pulled lever back to haul in winch, it didn't do it but everytime I pulled it back the second time, it worked fine.

mad murdock · « **Reply #1 on:** February 01, 2012, 07:53:39 am »

Is the control valve in good order? (not leaking internally, especially in "neutral" position)? Another thing to be sure of, check all the obvious items i.e. fluid levels, band adjustment etc. I hope you get it figured out! And welcome to the Forestry Forum rockwall!

rockwall · « **Reply #2 on:** February 01, 2012, 07:57:20 am »

I don't see any leaking going on. Fluids were good.

thecfarm · « **Reply #3 on:** February 01, 2012, 08:02:23 am »

rockwall,welcome to the forum. Using the skidder just on your land or making a living with it? Just want to know. Have a sawmill? Other toys?

http://www.forestryforum.com/board/index.php/topic,13313.0.html

Check out this thread,Timber Harvest Methods.

rockwall · « **Reply #4 on:** February 01, 2012, 08:10:28 am »

Thanks for the welcome. Old logger(is 60 old?) working in woods, mainly in winter on my own land or other's if the job comes along. Right now cutting really nice hardwood, landowner is doing the chopping and I'm yarding. It was going great till winch acted up, but we get her going again.

oldseabee · « **Reply #5 on:** February 02, 2012, 07:58:16 am »

First, the Clark Winch has no bands. Inside the drum there is a spring loaded large clutch pack that locks the drum to the drive gear. The input drive shaft drives another clutch pack that is energized with transmission clutch pressure when you want to winch in. To the right side of the front of the winch there is another small clutch pack that acts as a brake to prevent drum creep due to internal friction at the input clutch. This is energized when the winch is in neutral or freespool. Freespool is energized by transmission clutch pressure applied to a piston inside the drum to compress the springs and free the drum to turn freely when the cable is pulled out, but to keep the drum from coasting and snarling the cable there is a small brake that drags on the drum, it is adjusted by the "T" shaped handle on the right side of the winch.
If Trans clutch pressure is too low the freespool clutch may not release all the way. However the small brake at the front of the winch should lock the internal drive line, if the trans pressure is low this brake can slip. Pressure should be 240 to 280 PSI at idle with hot oil. If the input clutch has warped plates in it, it may have enough drag to over come the brake.
The controle valve has 3 spools inside. that work inside each other, if one of them sticks it can cause problems in the winch.

rockwall · « **Reply #6 on:** February 09, 2012, 04:17:08 pm »

Thanks oldseabee, we tested for pressure at end of hose, none, we took out winch control and found a broken spring and a torn gasket. We got new parts and installed still does not act right. It will creep in in hold position. What should we check next?

oldseabee · « **Reply #7 on:** February 10, 2012, 08:36:02 am »

check pressure to the winch drive line brake, is at the right side of the front of the winch looking at the front of the winch (240-280 PSI with hot oil at low idle). it is a 3disc clutch pack that is supposed to keep the winch from creeping due to internal friction at the input clutch. Either it isn't getting enough pressure to hold the internal drive or the input clutch has some warped discs and is dragging enough to overcome the brake. The other possibility is that the brake discs are worn out and slipping

rockwall · « **Reply #8 on:** February 10, 2012, 09:51:25 am »

Thanks again. When we put the winch control back in and started it up, the drive shaft wouldn't turn. Couldn't drive skidder, If we held the winch control in (pulling in) position then the skidder would be able to move. I know you mention to check pressure at brake which we did the first time but oil might not have been hot we just let it idle for about 20 minutes, got a reading of no pressure, so we overhauled the winch control. Now it seems we are onto the brake, do we need to test pressure before hauling brake apart, if so how do we get oil hot if it won't drive with winch control in hold position? If it turns out we need to look at brake do we need to lift winch up out of skidder? Thanks your information is really,really appreciated.

oldseabee · « **Reply #9 on:** February 10, 2012, 01:48:36 pm »

When you were into the brake, did you take the bearings out? What looks like adouble bearing is really a sprag, (one way bearing) it locks the shaft in one direction and lets it rotate in the other direction. If it is installed backwards the winch won't winch in. You say that the machine won't drive or move in gear, will the winch propshaft turn with the transmission in neutral? with the machine shut off, can you turn the winch propshaft by hand. If not, the input clutch may have broken or warped plates which will lock the winch drive to the propshaft, and with the winch control in the hold position the brake is applied which will lock everything up, when you put the winch control to winch in the brake will release letting the tractor move.

rockwall · « **Reply #10 on:** February 10, 2012, 03:42:44 pm »

We didn't get into the brake yet. We just put new spring and gasket in winch control and put that back into skidder. The propshaft can be turned by hand when machine is off. But winch control has to in pulling in position to drive skidder. How should we proceed?

oldseabee · « **Reply #11 on:** February 10, 2012, 04:10:14 pm »

First I would check that the lines to the control valve are in the right place. From the handle back, on the bottom first Winch in supply no pressure, bottom next is the drain line back to trans, bottom next is supply to the winch valve whith constant pressure when ever the machine is running, on top of the valve is the supply to the winch brake which should have pressure on it. these are all with the winch in the hold position. If the lines are right then there may still be a problem in the winch control valve.

rockwall · « **Reply #12 on:** February 10, 2012, 05:01:53 pm »

Again Thanks so much. I'll let you know how I make out.

oldseabee · « **Reply #13 on:** February 11, 2012, 07:06:06 am »

Sorry, I didn't mention the line to the freespool clutch which is the one between the drain line and the winch supply line.

rockwall · « **Reply #14 on:** February 11, 2012, 11:26:10 am »

Again thanks for the precise info. I'll get to working on it on Weds. and let you know how it went. Question: How come people stress to check pressure when oil is hot?

snowstorm · « **Reply #15 on:** February 11, 2012, 01:52:20 pm »

Quote from: rockwall on February 11, 2012, 11:26:10 am

Again thanks for the precise info. I'll get to working on it on Weds. and let you know how it went. Question: How come people stress to check pressure when oil is hot?

so you get a true reading. your engine oil pressure will read higher when the oil is cold dosent?

oldseabee · « **Reply #16 on:** February 11, 2012, 02:04:00 pm »

The temp wouldn't matter as much if there was multi weight oil in the systems like 15W40 or 10W30 where the viscosity stays more constant. The single weight oil like 20W or 30W is thick when it's cold and thins out as it warms up, so the pressure will read higher with cold oil and give you a false reading, you want it at it's lowest viscosity because that's when it will bypass internally in the pump, and past the seal rings in the clutches, and spools in the valve.

rockwall · « **Reply #17 on:** February 16, 2012, 05:20:30 am »

We double checked hoses to winch control, took out winch control and inspected inside. All was right inside.Tested for pressure at brake 260psi. It was still not acting right. In hold position it would keep the winch reeling in. So we took winch off and tore into the input drive shaft clutch pack and found worn discs and two discs were welded together. I called Harold's Logging in Hampden,Maine and they said they had the parts and since I had the winch out, take the brake clutch pack apart and check that disc, sure enough that disc was toast. Thanks to Harold's, they saved me a good two or three days and a lot of frustration by mentioning to check the brake clutch. It's great to have parts people looking out for you. So off to Harold's today, will let you know how successful we are.

oldseabee · « **Reply #18 on:** February 16, 2012, 10:30:52 am »

In the hold position there should be no pressure at the input clutch so the winch should not try to winch in with the brake on. If you disconnect the line to the input clutch put a guage in the end of the hose there should be no pressure in the hold position, at the same time see if the winch is still trying to winch in. That would indicate a bad input clutch, which is what you found.
Normally if the input clutch is packed up, you can't turn the input shaft easily by hand with the engine shut down.

oldseabee · « **Reply #19 on:** February 16, 2012, 10:41:10 am »

When you go to repair the input clutch, be sure to check the steel discs for flatness. A lot of times they are stamped parts and will be slightly dished, this is OK as long as they are all put in with the dish facing the same way, if you put them in with the dish's opposed that will take up some of the internal clearance required for the clutch not to drag when it is not pressurized and it can also limit cooling oil to the opposed disc's if the outer edges are touching and the gap is in the middle.

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Author Topic: clark winch (Read 652 times)