440a winch slipping

duckslayingpro · April 15, 2012, 06:18:24 PM

I was just wondering some of you guys thoughts. i plan on ordering a new band this week. no matter if it is a big drag or small drag winch will slip. With band adjusted all the way down it will still free spool with ease but will not hold a drag. i beleive it is in the control valve. i took it apart and the spool has a score mark on it where the detent ball has been rolling back and forth. Is it time for a new spool? if i get the handle/spool valve in a "sweet spot" it will hold. until i hit a good bump or or something then it starts unrolling with the logs behind it. any information will be gratly appreciated.

duckslayingpro · April 15, 2012, 06:20:06 PM

I do not see any hydolic fluid showing up around the drum or band.

Bobus2003 · April 15, 2012, 11:00:20 PM

Does it squeal when it it slips out? My Winch is brake band is worn out and needs to be replaced per JD, but mine will always squeal when it first breaks free, then goes relatively silent..

duckslayingpro · April 15, 2012, 11:18:49 PM

No it is silent when it is slipping.

duckslayingpro · April 15, 2012, 11:20:04 PM

Could my tension springs be weak? maybe need new ones?

snowstorm · April 16, 2012, 06:58:03 AM

Quote from: duckslayingpro on April 15, 2012, 11:20:04 PM
Could my tension springs be weak? maybe need new ones?

they could be after all they could be 40 yrears old. on the band you will see where parts of it are welded together have seen them break there . if there is no oil leaking from the valve it should be ok. take the big cover off left side so you can see everything. you can freespool with this cover off do not wind in or you will have oil everywhere. any oil on the drum or in the heat checks of it. take it off use a propane torchlightly heat it the oil will burn out of it

tjdub · April 16, 2012, 12:36:02 PM

Quote from: duckslayingpro on April 15, 2012, 06:18:24 PM
I was just wondering some of you guys thoughts. i plan on ordering a new band this week. no matter if it is a big drag or small drag winch will slip. With band adjusted all the way down it will still free spool with ease but will not hold a drag. i beleive it is in the control valve. i took it apart and the spool has a score mark on it where the detent ball has been rolling back and forth. Is it time for a new spool? if i get the handle/spool valve in a "sweet spot" it will hold. until i hit a good bump or or something then it starts unrolling with the logs behind it. any information will be gratly appreciated.

It would be very odd that the spool valve is to blame. Usually if your spool valve is leaking internally it will manifest itself as either NOT going into to freespool or NOT pulling strong unless you crank up the engine RPM. In order for the spool valve to make the brake slip, it would have to be leaking in such a way that it's actually activating the brake cylinder when not in freespool position. I don't know if it's even possible for a spool valve to fail that way (at least not the rotary valve assuming that's what you have) when they leak they just lose PSI and leak the oil back into the return line. Anyway, it should be easy enough to see if this is happening if take the cover off. You would see the brake cylinder getting activated when it's not supposed to.

Have you gone through the brake burnishing procedure yet? You adjust the brake band by measuring the distance between the two spring holding pins. Then you hook the cable onto a big tree and pull like crazy (50ft or so?). Then just go blow all the newly generated brake dust out and readjust the brake band using the same measurement. I can't remember the measurement exactly but I can look it up in my book if you need it. If your band is already adjusted all the way up, there probably isn't enough fiber on the band for this to work anyway though

snowstorm · April 16, 2012, 06:01:37 PM

440a did not use the rotary valve. burnishing the band works good on a new band dose nothing for an old one

tjdub · April 16, 2012, 10:35:14 PM

Quote from: snowstorm on April 16, 2012, 06:01:37 PM
440a did not use the rotary valve.

Oops, never mind then. I only know anything about the rotary ones.

Quote from: snowstorm on April 16, 2012, 06:01:37 PM
burnishing the band works good on a new band dose nothing for an old one

I'm going to have to disagree on that one. My winch sat unused for many years before I resurrected it and I could never get it to hold a hitch worth a darn. I kept readjusting the brake band, but it never helped much until I burnished it and it's held perfectly ever since. JD service manual says pull 20-30ft of cable, readjust spring tension measured 4 11/16" from bottom of spring anchor to bottom of spring anchor, and if it still doesn't hold, repeat the procedure.

YMMV, but it worked for me.

duckslayingpro · April 17, 2012, 12:08:11 AM

well put a new band and springs on today. i only tried to burnish the band 2 times. may need to try some more...
adjusted band to the 4 11/16" per tech manuel specs. thought i would try to get a drag to see what it would do. as i am driving down the skid trail i notice my cable is about 30 feet behind me and unwinding... at first i thought no big deal i must have left it in free spool and it grabbed something and just kept unwinding. so i winched it up and continued on my way. looked behind to see it had happened a second time. winched it back up and watched it as i continued on. letting the skidder pull itself in first gear in low range it never moved. but shift into second and give it some fuel and it just starts unravling.
i am somewhat past the 4 11/16" on the adjustment now and it still does it.

i am not sure what would cause this except maybe the "detent" mechanism in the control valve??? while i had the cover off adjusting the band i would start the skidder with the control valve in the "free spool" position to make sure it wasn't to tight to pull cable out. i then put it in the hold position and noticed fluid coming out of the line that connects to the side plate cover.
to my understanding it should not do this? or am i thinking wrong?

i took the control valve off and brought it back home with me from the woods tonight to look at it. nothing seems to be wrong with the parts. the spool where the detent ball rolls on it shows some wear but does not seem damaged?
Any thoughts or other info is greatly appreciated.
thanks everybody,
duckslayingpro

lonewolf · April 17, 2012, 12:23:14 AM

Don't know for sure I've never had that problem. I used to have a 540A trying to remember I think it had a 90 degree fitting on it with a o -ring if you are leaking fluid I would bet that's your problem.

snowstorm · April 17, 2012, 08:48:54 AM

the short line is leaking? or out of the center of the big cover? there is a seal and hollow pin in the center of the big cover it was on later models replaced with a sqivel fitting

duckslayingpro · April 17, 2012, 11:31:48 AM

It is the line coming out of the control valve that connects to the pipe plug on the top half of the side cover. i beleive that is the pressure line for the wind in position.

duckslayingpro · April 18, 2012, 07:38:10 PM

While the control valve is on bench i pushed the spool in like it would be on the skidder to wind in and let it out and it doesnt return all the way to the center for the "hold" position. could the return spring be weak? or do you think something else may be going on inside of it? i ordered a new spring today hope that is what it is but it wont be in til friday. hope this fixes it. juat wanting to know you guys thoughts.

snowstorm · April 18, 2012, 08:55:40 PM

simple test blow thru it since you have it off

duckslayingpro · April 21, 2012, 12:40:09 AM

Blew air through it and everything seemed good. put it back on skidder tonight it does not have fluid comeing out of the winch in line. but will still not hold the logs up at all.
if i do not give the skidder any fuel and let it pull itself it will hold but if i give it fuel to get to moving it will not hold.
any information is much appeciated. i really need to get this fixed.
thanks again

snowstorm · April 21, 2012, 09:48:25 AM

i am gonna say its oil on the brake drum. there will be heat checks in the drum oil collects there over the years. you spray it with either or brake cleaner it looks fine. the more the band slips the more heat the more oil seeps out. dosent take much. i have done this with mine and others i worked on. take the drum out clean it there heat it not a lot. the old trick for the oil soaked bands was set it out on a stone wall for a few years. the guy that told me that worked on deeres for 50+ years. if it isnt springs or adjustment or band then its too slick. when you adjust the band leave the big cover off. you can run it and freespool DO NOT WIND IN with the cover off you have room to work and can see whats going on

BBTom · April 21, 2012, 10:30:52 AM

If I am reading correctly,
Winch holds at idle.
Winch freeespools(does not hold) when engine rpms are high

I have no idea how it could happen, but it sounds like the release cylinder is being activated at high rpm. In other words your control valve is leaking by at higher psi.
bypass the control valve so no hydraulic pressure can get to it, then try to drag the line out of the winch. If the winch holds then replace the control valve.
If the winch does not hold then make certain the release cylinder is releasing, that there is no oil on the band or drum, etc.

duckslayingpro · May 01, 2012, 11:08:58 PM

I checked the drum. it does not have any oil there that was visible. but while had it all apart went ahead and cleaned it up with brake cleaner. winch still did not hold.
i had another guy rev the skidder up while i stood at the winch and looked through the little side plate for adjusting band. when.he would rev the skidder up i could see the brake cylinder push the band away from the drum like putting it in freespool. I am completly stumped.

BBTom · May 02, 2012, 03:45:07 PM

Something is putting pressure on the release cylinder, my guess is a bad control valve.

One other remote possibility is that the return line from the valve could be plugged/pinched/collapsing and the flow through it at higher RPM's causes pressure backup into the cylinder.

I cannot think of anything else that would cause that to happen.

tjdub · May 02, 2012, 04:02:14 PM

Quote from: BBTom on May 02, 2012, 03:45:07 PM
One other remote possibility is that the return line from the valve could be plugged/pinched/collapsing and the flow through it at higher RPM's causes pressure backup into the cylinder.

The spin-on oil filter is on the return side. Maybe it's getting plugged up?

duckslayingpro · May 03, 2012, 09:31:13 PM

I changed the filter when i moved onto the job i just finished. but the skidder sat for around a year so it might be time to change it again. i will check lines for obstruction and change filter and see what happens. thanks again guys

snowstorm · May 04, 2012, 06:49:10 AM

have you tried running it with the side cover off so you can see whats going on? not the little cover. you can freespool with it off dont wind it in.

duckslayingpro · May 06, 2012, 03:07:33 PM

Yes. i tried with side cover off. Looked at lines and changed filter this morning. lines are not clogged and did not find anything in filter. same thing though. hold at idle. wont hold at higher rpms. with cover off you can see the brake cylinder activate like putting it in freespool. i guess it is in control valve... but nothing looks bad inside the valve.
thanks again guys

duckslayingpro · May 07, 2012, 10:05:51 PM

Also if i pull the control for the winch shaft out (the driveline shaft for the power to the winch) the winch will hold very good. does not slip at all.