Snow Plow Inspection 

When weather is favorable, even during the season it is a good practice to inspect your snow plows regularly. If you have a heated shop, even better. I can't tell you how many damaged snow plows I have seen over the years where the operator or owner had no clue the snow plow actually needed repairs. Naturally, there are times when you know you need to give your snow plow a once over, such as when you hit an obstacle hard enough to stall the truck! When you have an impact with an immovable object, something on the snow plow will usually give, either by bending, flexing, or cracking. Just because the snow plow "still works" doesn't mean that nothing is damaged. It also doesn't mean that nothing is worn out. There are many places the steel "wears out" on a snow plow system.

Each plow being designed differently, will naturally have common failure areas, specific to that brand and model of plow. All plows have typical failure areas, just like anything else mechanical. Some of these areas are common to all plows, even when designed differently. I want to add that by pointing out these areas on the various plows, I am in NO WAY trying to bash any brand of plow, or design. It is rare when a machine can't be improved in some way. Plows are machines, and all machines fail sooner or later too. I will try to go over the various problem areas, and points to check.

Let's start with one of the most common failure areas.

The Center Pivot Bolt

It is not uncommon for the steel to crack around this bolt. This bolt, and the surrounding steel takes a tremendous amount of beating from plowing. All of the force of anything against the moldboard is transferred to the A frame via this bolt and the surrounding steel. The plow is tipped up in this photo for easier viewing.

Area Prone To Cracking

You can see the green line where cracks typically develop. It is where the metal is the thinnest as you can see. You can also some remnants of grease. It doesn't hurt to keep this pivot point greased. It will help keep the plow angling freely. Wear is a problem here, and using a center bolt with the proper shoulder length is important. In the future, I would like to see plow manufacturers develop some type of tapered bearing, or roller bearing center pivot. At the very least devise a way to grease the center pivot thoroughly. Nothing but steel wearing on steel as far as all the pivots on a plow go. The more you can keep greased, the less the parts will wear. The bolt in the above picture is installed wrong. The threads should be up with the nut on top. This is because typically the bolt is longer, so it has more shoulder, and if it is installed as above, the threads will hit the angle iron below them when the plow trips.

Top Of The A Frame

Here is a top view of the center pivot area. You can see the rust in a line across the top. This is because the metal is flexing so much, the paint won't stay on it. It cracks off. Sooner or later there is going to be a crack in the steel here. Anytime you see cracks in paint on a weld, or on a short section of steel, it is a sign of high stress, and an eventual failure point. This A frame should be replaced, but might last a few more seasons. You can bet when it does fail, it will be during a storm. To be safe, and prevent downtime, the A frame should be replaced now before it cracks. In this photo you can also see the nut of the center pivot bolt. The steel around the bolt should be cleaned and inspected for cracks. A smear of grease on here is helpful too. Every year it is a good practice to remove the center pivot bolt. Inspect the holes in each piece of steel it holds together. If the holes are really getting oblong, then it might be time to change the A frame, or have the holes welded up and made round again. Smith Brothers Services, LLC does this all the time. Oblong holes mean room for "play". As the bolt moves freely in the oblong hole, instead of absorbing the stress and load, it "hammers" the steel while both pushing and backdragging, eventually resulting in cracks.

Tip Your Plow Up

Tip your plow up with the moldboard facing down. Inspect the center pivot area shown in the photos above. Stand back and take a good look at your A frame and plow. You can see the A frame of this plow is bent right where the green circle is. It took 2 years, but the angle iron of the A frame cracked right where the center of the bend is. The stress finally got to be too much, and the metal let go. When the A frame was changed, it was discovered that the center pivot had a crack in the steel as well. Because the owner never tipped up his plow, let alone inspected it, these problems were just waiting to rear their ugly heads in the middle of a storm, and they did. You can see the trip spring adjusters on this plow are barely protruding above the top edge of the mold board. These have a lot of adjustment left in them. When there is 3" of thread sticking up above the moldboard, you will need new adjusters. It is easier than trying to deal with reusing the adjusters, and since when you run out of adjustment, the springs need to be replaced, you can pick up both items at the dealer. When replacing a trip spring, sometimes you have to loosen the adjustment on the other springs as well as removing the adjuster with the spring you are replacing. It is often easier to cut off a rusty adjuster than to use 2 wrenches to get it off. A trip spring is adjusted properly when the coils are just starting to separate. Keep tightening the adjuster until you can slip a matchbook cover, or folded piece of paper between the coils. Trip springs should not be loose and "wobbly".

Lift Arms

Lift Arms end up with the pivot hole in them worn to an oblong shape over time. This contributes to a "sloppy" plow. I put a piece of masking tape on the back of this one to help show how oval the hole is. In the future, manufacturers should use a replaceable bushing of some type, rather than making us replace the lift arm. You can buy one for Meyer plows with a bushing and grease fitting from Smith Brothers Services, LLC. One of the biggest contributing factors of this wear is bolts with an improper shoulder length. Plow manufacturers often include these bolts in their hardware assortments. They must specify the diameter of bolt, and length, but not shoulder length when they put the assortments together. Ignorant mechanics will often use the wrong shoulder length. Better to use a flat washer on the head and nut, than to expect metal parts to pivot on the threads of the bolt. Bolts that have been installed like this are only good as "emergency spares" since the threads are damaged and often VERY worn.

Pivot Pins & Bolts

This plow uses a sleeve and pin as a pivot to allow the moldboard to trip. Actually it uses two of them. In this photo you can see a piece of 1" x 1" solid steel stock is welded in on top of a 1" sleeve behind the 2" x 3" piece of rectangle 1/4" steel plate. On the moldboard side, there is another steel sleeve, with that large washer welded to the end. In the far left of the photo, you can barely make out the cotter pin in the end of the sleeve which holds the pivot pin in.

You can see the pivot is dry.

 Greasing these pins is important, and some plows have grease fittings on them. This plow used to, but they got broken off at some time. Funny there is only a grease fitting on one sleeve, and none to grease the sleeve on the moldboard. The pin can turn in the sleeve on the mold board, so that end should be greased too. A common problem with these pivot pins is they are not greased enough, and become seized. It is a big project trying to get the pins out once seized, and often easier to just torch out the sleeves, and weld in new ones. The last seized one I worked at getting out took over 4 hours, with a torch and air chisel, cut off wheel, pry bar with cheater and 500 pounds on it... It would have been easier to torch and weld. Even with greasing normal wear will occur at this pivot. The ends of the steel sleeves become cracked and mushroomed out. The pins become worn, as do the inside of the sleeves. This particular plow manufacturer sells replacement sleeves and pivot pins. My plow is 20 years old, and is due for new ones. The plow in the picture will need them soon, and it is less than 10 years old. It has already had the pivots reinforced once. Although my plow needs to have the pivot pins and sleeves replaced, I could easily get a season out of it, but, when one of the pins does fail, you can bet your bottom dollar that it will be during a storm. I have been carrying a replacement pin in the truck for years, and have sleeves at the house to weld on. I just don't have a need to. But if it isn't snowing where you are, and you can afford the parts, and if you have the skills, tools and time, then why not do it?

If you need to paint bare metal, forget about 'regular' primer. It does not etch into the metal. Etching is very important. Eastwood sells Self Etching Primer in handy spray cans for small areas, and in quarts.

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