Winch Clutch Problem.

[NAM VET]

It is pretty obvious why the Army assigned a driver/first echelon mechanic to each vehicle. Because it is necessary. At least my truck now starts and drives perfectly, after the "issue" with the tiny fuel filter causing a burned out Facet fuel pump.

About a year and a half ago decided it was time to rebuild my frozen LU4, which was fortunately frozen in the engaged position, making it still possible to power out and power in the cable. So powered out the cable, sourced the necessary parts, and with a lot of effort, was able to disassemble it. One of the biggest challenges was getting a slightly bent clutch rod out, and then pulling the drum off, the shaft keys were broken and frozen in their slots.

But got it done, fortunately the expensive gear wheel was fine. When back on, using a hoist to lift it, the clutch arm swung the "dog" in and out of its drum engagement fine. I sourced a new clutch rod, and new "c" arm. But the new rod was ever so slightly different in spec than the old bent one, making it difficult to get the bottom retainer ring in perfectly. Used red Loctite on the set screw holding the "c" onto the shaft. Never used the winch again, and kept it covered side to side with waterproof canvas.

So yesterday, had a new canvas cover made, and found my clutch arm lever will not push the "c" in far enough to engage the drum's end. Tapped on the arm, banged on the drum and clutch housing, and I have it aligned up with the painted reference mark where the drum/winch has to be to allow the "dog" to slide in and lock the shaft to the drum. I have looked down into the fill hole and can see where the "c" moves without resistance but just not far enough to engage the dog with the drum.

I have tapped down and pried up the clutch arm, to no avail. The drum free wheels fine. My next try is to start the engine and rotate the main shaft to a different position, and see if it will then allow the "c" to slide the dog into the drum's end. For some reason, my "dog" is I believe hitting the rim of the drum's engagement ring, and won't seat. Perhaps from an ever so slightly out of spec replacement rod, putting the "c" too high or too low.

I just can't take it off again, I gave my engine hoist away, and can't handle the winch. Plus, I just don't have the energy nor time to do it all over again.

Here are a few pics, I painted the "c" and the dog to make them more visible. Any thoughts would be appreciated. will put pics in next post, to avoid loosing this. Hal

[NAM VET]

here, the struck keys, I had to have my machine ship remove them. Shows the end of the drum, where the "dog" engages to lock the drum to the shaft. hal

[NAM VET]

here, the "c" on the clutch shaft, this fits into the dog's groove, and swings the dog in and out of the drum's end. I painted my clutch internals to reduce rust and just for fun. I can't remember if I ended up using the original or the replacement C arm, but used a new set screw and red Loctite. It seemed to move in and out fine. hal

[NAM VET]

here, the shaft with the "dog". I used fine cloth sanding strips to remove surface rust. It seemed to slide fine on the main shaft. But it now I believe won't slip into the drum's end to lock them together. I want to try everything before even thinking about puling it all off for a check. hal

[PoW]

To get it into gear it has to have the input shaft turning.

Don't do it with the cable fully wound, leave enough so you can get back into the cab, best to have some else to help.

Once so,it is best to leave it in gear, PTO in neutral, locking flap engaged.

Otherwise, it is really tough down the road for a single operator to work things conveniently.

Yeah, I know, some will say "that is a disaster waiting to happen". Never has in over 50 years of M37's here.

PoW

[NAM VET]

so went out this morning, and used my inexpensive fiber optic screen, but really couldn't make much out of that. So rotated the drum away from where my prior markings are, and with gentle pressure about an eighth turn the dog clicked into the drum's end. Of course the drum/dog can only engage in two positions, and for some reason, when I had earlier tried to rotate the drum away from my markings, it wouldn't engage, but now seems fine. So made new paint dabs where it engages now, and will leave the clutch lever engaged. Once, my grandson and I were out in the woods, and I got stuck, and my winch was frozen in the engaged position, so we were able to power the cable out, hook up, and power back in, letting us escape. The dog slides fine now, but just to be safe, will leave it engaged, "just in case." I doubt I will ever use it again. I may participate in a Cars and Coffee at Ft Jackson, here near Columbia sat.

I am well aware of the dangers of winching. About a decade ago, video'd four dozers pulling a sunken dozer and a sunken big Volvo dump truck out of our beach's sand, when they toppled over into the water when pushing sand for a new breakwater. I'll post that Utube soon. I thought the owners were too close to the cable and would have been killed should it slip or snap. Both dozer and Volvo were fully submerged.

But I am just so relieved that once again, everything working fine on my truck. thanks as always.... hal

[Cal_Gary]

Glad you got it solved, Hal. I still need to tackle my winch inspection/rebuild etc. so threads like this are teaching me what to look out for, so thanks!
Gary

[NAM VET]

it was nearly impossible to pull the ends off my winch, due to rust on the shaft. The important thing is luck out with no wear on the big bronze gear, as they are very expensive if you can can even locate one. I used the auto craft shop at Ft Jackson, about an hours drive before we moved to near Columbia, where they have presses and such. For a few bucks an hour, used their big machines to do what I couldn't do at my work bench, Getting the old bushings out was a chore, had to grind and file them to get them to break and pry out. New shafts are available, as are the seals. Again, used the shop's press to insert them, as well as the new bushings. I decided to reuse my old main shaft, and removed the nicks with fine Emory cloth. Painted the main shaft to reduce any future rust. Charles Talbert has some suggestions on rebuilding a LU4. Sourced the special oil from Walmart mail order. It is a trick to keep the dog lined up with the main shaft when putting it back together; I used a sticky grease to hold it in alignment. New keys are available too.

I can't lift my winch even without any cable on it, so used my engine hoist to remove and reinstall. I had to use a small jack to ever so slightly separate the front bumper extensions to allow my bolt holes to line up when remounting. Don't forget to insert the PTO drive shaft into the gearbox before you fully mount the winch. My winch drips about one drop of oil every few days from the passenger/clutch side, something I can live with. My drum end flanges were slightly bent so used the press to move them back into near alignment. Once you get the hang of it, taking it back apart is a few minute task, which I had to do several times. I used some long clamps to help pull the two ends together symmetrically. Rewinding the cable is easy, use gloves to guide it back on tightly with someone in the cab. Remember if if the cable rewinds from over or under the drum.

It was a challenging beast to get back into running condition. But mine is at least no longer just a decoration. I just had a new water proof cover made at a local canvas/boat upholstery shop, they had left over military "canvas" from prior military contracts, it covers the winch complete, reducing the risk of water intrusion. Good luck.... Hal

[ez8]

This is all good info for those of us still in the midst of our winch rebuilds. Thanks, Hal.

[sturmtyger380]

new water proof cover made at a local canvas/boat upholstery shop

What does that look like? Can they make other copies?

[NAM VET]

Sturm, my prior but worn out Duck Canvas cover covered the whole winch, side to side, not just the wire. Reduces the risk of water intrusion into the side seals of the winch. So took my old cover to a local shop which has contracts with boat builders, and in the past has made up contract HUMVEE products out of a tuff, water proof, thin fabric, and had left over desert tan fabric. A really big shop. They copied my old cover, added more grommets, and did not charge me, saying they would look for my truck in an upcoming parade. I painted it black, and use wire ties to completely cover my winch. The told me they don't usually work for private small jobs, because they work with boat makers for their upholstery for boats.

But any canvas or upholster shop can make one up for you out of suitable fabric. Here, protecting my winch... hal

[NAM VET]

by the way, a year or so ago, I posted a long discussion of my own disassembly and assembly of my LU4, so if you want to search LU4 on this forum, all that is there. hal

[NAM VET]

back in '17, when I got my truck, and began its restoration, one day I removed the lower plugs on each end of my winch, and water came running out. No wonder it was frozen with rust.

So I decided to keep using and now replace the full cover, to avoid risks of water intrusion past the seals on the ends. Not as "warlike' as just a cable cover, but surely more protective than the "bikini' cable cover others use. Hal