Winch Repair & Rebuild

[maineSS]

Moving on with winch lubrication- you'll note that Braden's viscosity spec changes with ambient temperature. It's a balance between the oil being thin enough to flow between the gear teeth, but thick enough to resist shear and the wiping action of the worm. The lower the temp, the lighter the viscosity- as a rule of thumb, the lowest working temperature of a lubricant is 10 deg above its pour point. The higher the temp, the higher the viscosity needs to be. Too high a viscosity at low temp means grinding gears, as does too low a viscosity at high temps. When a worm gear is working, it runs hotter than other gear types- about 90 deg over ambient vs 50 deg. This is why the usual viscosities for indoor worm gear sets run around ISO 460-680, much thicker than other gear types.

How well does the traditional 90 wt SAE work in a worm gear? If you look at the viscosity cross-reference tables mentioned earlier, you'll see that an 85 wt oil covers ISO 100-130, a 90 wt covers ISO 130-320, and a 140 wt covers ISO 320-680. Looking at Braden's actual chart, I'd say 90 wt would be safe from -5 to 70 deg. Back in the 40's, gear oils were limited in technology and availability, and 90 wt was the best most people were likely to find. The introduction of lead styphnate as an EP agent in the 50's helped, as it didn't attack brass/bronze. When Dodge specified 90 wt, it was likely thought most people wouldn't use the winch continuously like an industrial application, so excess wear wouldn't be a common problem. In the 70's, lead styphnate was replaced by sulphur/phosphorous compounds, which quickly destroy brass/bronze under certain conditions. This is when Braden started testing for oil compatability and recommending specific oil brands. Today, those brands are: MOBIL Mobilgear XP; SHELL Omala; CHEVRON Gear Compounds EP; and TEXACO Meropa in the appropriate viscosity for each temp range (Tier). Synthetic versions of the listed brands are fine, other brands should equivalent in specification to the listed ones.

If you have a new set of gears, they have to be broken in on mineral oil BEFORE switching to synthetic. Braden recommends 10 pulls at 60% of the load rating of the winch. Make sure the bushings and gears are lubed before starting the pull by running the winch disengaged for a few minutes. If the gearcase starts getting hot, stop and let it cool before resuming breakin.
I happen to have Meropa available at work, so that's what I'm using for breakin. Others will have to enter the wide world of industrial lubricants- on our next lube essay....

[maineSS]

There are two types of mineral-based worm gear oils, and two types of synthetic available. Your biggest problem is finding small quantities at a reasonable price- most of these oils cost around $200 for a 5 gallon pail, and 5 gallons is the smallest size normally available thru lube distributors.

The traditional oils are "Compounded Gear Oil", which are mineral base oils mixed with 4-6% acidless tallow for better wetting ability. These oils were originally used in steam cylinders (Mobil has a 600 wt "Steam Cylinder Oil") because of their ability to displace water. Since they're mainly ISO 460 and above, they're mostly limited to temps above 50-60 deg, which crosses them off most oudoor user's list.

The other class is the EP "Extreme Pressure" oils. Most of these have sulphur/phosphorus as the EP agent, some have borate or "non-active" sulphur chemistries that don't attack brass/bronze. The early pressure to develop "non-active" additives came from Porche, who discovered that the synchros in their transmissions were being eaten up. Sulphur/phosphorus additives activate with heat to form a protective oxide coating on ferrous metals. Unfortunately, they rapidly corrode brass/bronze unless they are deactivated. You can recognize this if the sides of the brass/bronze gear are black, and the teeth are worn razor-thin and bent over- it doesn't take very long under load. Since worm gears run about 40 deg hotter than other gears, you need to ask the lubricant vendor if a "non-active" oil is still safe for worm gearing, because heat is what activates sulfur/phosphorus. Talk to a lube engineer- not a salesman! Most of today's automotive GL-5 rear end oils have high levels of sulfur/phosphorus, and should be checked out thoroughly before use in your winch. The main disadvantage of mineral base oils is the necessity of having at least two different viscosities (ISO 220/460) on hand to follow seasonal temp variations in most of the U.S.. Using an 85-140 wt multigrade is tempting, but shear breaks down the viscosity modifier rapidly, and worm gears are all about shear. When the modifier is gone, you're left with just an 85 wt oil. Fortunately, there's a better option- single wt synthetics.

There are two flavors, polyalphaolefins (PAO's) and polyalkene glycols (PAG's). PAO's are the way to go- PAG's aren't compatible with other oils, and attack seals and paint. Since synthetics have low pour points, you can use an ISO 460 at below zero- some pour at -50! You do have to check for sulphur/phosphorus, as some synthetics have these as EP additives. I'm leaning toward a worm gear oil made by Lubriplate- (PN LO981)- you can get it in 1 Qt bottles thru distributors! It has a corrosion test rating of 1a- the best available for brass/bonze, and a pour point of -50 deg. Other vendors such as Amsoil or Royal Purple likely have similar products, but you may be looking at that 5 gal minimum.

In order to use synthetics, your worm shaft and seals have to be in good condition, or the synthetic will be gone. You will also have to either seal the case bushing with an "O" ring or grease groove, and keep an eye on the level. Do this, and your gears will last a long, long time. Site #3 relates the experience of a can manufacturer who was replacing a worm gear set 4 times a year at a cost of $12,000 per event. After replacing the compounded gear oil with a synthetic, gear temps dropped 20 deg, and no failures occured for 18 months, even though the gear sets ran at higher speed and load!

[Charles Talbert]

Great analysis concering oils, possible adverse effects, etc.

Checking out all the details is vital not only in the winch, but other components as well. Failure to do so has caused many problems for operators that were blamed on bad component parts, seals, poor quality workmanship, etc. The RIGHT lube is the life of mechanical components. Doing you homework in regards to up to date products as you have done in this case will update users of many better products that are out there today instead of trying to source products of many years ago that will not afford near the protection. Updating your components to avoid oil leaks is immperative also to a long running trouble free component. You have done a great job on research and putting proper updates into place.

Folks with the mindset that a 60 year old product is the best choice because the book says so, well they will be the loser. Technology has come a long way with mechanicals and lubricants in 60 years. Take advantage of it and build a better running, longer lasting, and leak free component. It cost a little more initially of course, but you will have a dependable component that runs great anytime you need it, and you can and will be proud of the unit you built.

[maineSS]

Charles- excellent point about yesterday's lubricants- like yesterday's gasoline, they're just not made anymore, you'll need a Time Machine to find them. Even if you did find them, there's much better available if you know how to look.

I suspect a lot of winch users are looking for an oil that doesn't cost too much, won't eat bronze gears like many auto store GL 5 oils will, and will cover a wide temp range. Their winch leaks a lot because of worn seals/worm shaft, and they need frequent refills. The closest possibilty I've been able to find is an 85-140 Super Tech semi-synthetic marketed by Wal Mart. It's made by Lubrizol. The engineer there said he didn't see any corrosion or lubrication problems other than the life of the viscosity modifier- which is why he couldn't fully endorse it for this use. If you're going thru frequent oil changes, viscosity modifier breakdown shouldn't be a problem, but everyone's winch use is unique, so this is very much a case of the the user being aware and watching his winch. If I come across something better that's widely available, I'll post it.

[Charles Talbert]

Charles- excellent point about yesterday's lubricants- like yesterday's gasoline, they're just not made anymore, you'll need a Time Machine to find them. Even if you did find them, there's much better available if you know how to look.

I suspect a lot of winch users are looking for an oil that doesn't cost too much, won't eat bronze gears like many auto store GL 5 oils will, and will cover a wide temp range. Their winch leaks a lot because of worn seals/worm shaft, and they need frequent refills. The closest possibilty I've been able to find is an 85-140 Super Tech semi-synthetic marketed by Wal Mart. It's made by Lubrizol. The engineer there said he didn't see any corrosion or lubrication problems other than the life of the viscosity modifier- which is why he couldn't fully endorse it for this use. If you're going thru frequent oil changes, viscosity modifier breakdown shouldn't be a problem, but everyone's winch use is unique, so this is very much a case of the the user being aware and watching his winch. If I come across something better that's widely available, I'll post it.

I don't know if you found this info or not, you may have already covered it.

I found out after talking to tech rep's at Royal Purple that they offer worm gear lube in both non-synthetic and synthetic products. The synthetic was quite a bit higher priced of course. His analysis was if high heat conditions were not an issue, the non-synthetic product should perform great. He felt their synthetic products would perform much better if heat was an issue, I can certainly agree with that point as we have already seen in components where heat was an issue become non issues just by changing to Royal Purple lube. It isn't uncommon for Royal Purple synthetic oil to lower operating temps by 20 degrees and more in some cases. Royal Purple is a great line of products.

[maineSS]

I've heard good things about their product also- seems to be available only thru dealers up here. Heat is usually a problem in continuous use (unless you live in Death Valley), most people normally are making occasional pulls. I think synthetics are the best way to go here, well worth the effort of changing out worn seals and worm shafts.

[Desoto61]

Advanced Auto seems to have a limited selection of their stuff. Mostly just the normal oil grades and ATF with maybe some gear lube but might be able to get more.

Summit Racing caries most of their line, not sure if the price is any better than a local dealer but was easier for me to get. I ordered lubricant for both my transfer case and my differentials from them. Not cheap but everything I had looked at seemed to back up their claims.

[Charles Talbert]

Royal Purple Industrial product suppliers

You will need to locate a Royal Purple Industrial lubricant dealer for many of their products, such as worm gear lube. Automotive suppliers won't carry that. Ours down here is Atlan-Tec, they cover both North and South Carolina, prices to us are much better than over the counter like NAPA, Car Quest, Advance, etc.

[Desoto61]

I've started putting my winch back together and ran into the issue of pressing the new bearings onto the worm shaft. Since I didn't have any extra spacers I had to find an alternative.

What I ended up doing was taking one of the old bearings and removing the cage and rollers. Then cut the inner race in two and ground down all the sharp inner edges. I also ground off part of the top lip so that it fit inside the cage of the new bearing better.

The shape of the inner race gave me a nice wide bottom to go against the base plate to press against. I had to press against the plate first and then re-position to press through the opening in the plates, otherwise the bearing wouldn't go on straight and would start moving the shaft instead of the bearing.

[Doc Dave]

DeSoto,
I posted something about my winch under the 1- ton power wagon section of the forum. I would like to get your opinion if you have time.
Thanks,
Dave

[Gordon Maney]

This is a really great thread.

[Desoto61]

Started putting the case back together last night and needed to make some additional gaskets for the drum shaft cover. As I don't have a way to turn down a piece of bar stock (or the bar stock) to make a punch for the bolt holes. I went digging around and found out that a piece of 1/2" type M copper tubing (left over from plumbing the air system) has the right ID.

I cut a short piece and ground the edge down to make it sharp. It worked OK but the copper is too soft and the end dulls very quick. However a piece of 1/2" steel or iron pipe from the local hardware store might just do the trick. I know the big box stores sell short connector pieces for a few $, the ends are threaded but you're going to grind them off anyway.

I have to stop by the store today so I might do some experimenting in the plumbing aisle and report back. The one gasket I made was enough for my setup but it would still be worth having a better version if it works.

[Gordon Maney]

Are you familiar with gasket making using a small, ball pein hammer?

[Desoto61]

Are you familiar with gasket making using a small, ball pein hammer?

No, can't say I've ever heard of it. Honestly other than using RTV or pre-made gaskets this is my first real foray into it. Most of it I cut out with scissors (outside) or a razor blade (inside) but the holes are too small to cut well with either.

[Desoto61]

One other little tip I figured out last night was that a 1-1/16" Craftsman socket is the perfect size for driving in the oil seals. It's big enough to fit around the inner rubber seal and small enough to fit inside the outer metal lip.

I used a flat bearing press to start it into the housing and make sure it was square with the bore, but that would only let me go flush with the back of the opening, which left a gap between the font opening and the seal case. The socket let me go the rest of the way. A little RTV around the bore before pressing the seal in makes sure everything is liquid tight.