Determining vee belt size, type, etc.

Okay boys, someone here must have some input on this. I've spent hours trying to determine what size and type of belt I have so that I can start looking for proper sized shives (sp?) to make a repair. What I have is a Melroe Bobcat 444 with the variable speed pulley drive set up. Yes, I know, it's ancient and a waste of time and money, but it's what I have and it works great when I can get it to work. The problem is the hydraulic variable drive pulley bore is so worn the I can't keep it from walking off the crank end of the engine. There just isn't anything there to do anymore with to secure it. I was fine until I took the totally bald car tires off it and put snow tread types on. I couldn't move on wet concrete, much less in mud with the bald ones and now I can't keep the torque from shifting the pulley assy off the crank. In searching for a fix I came across a guy on You Tube that used a solidly attached pulley system that looks fine for what I'd need it for. The problem is finding out what type of pulley halves, shives/sheeves I've always called them, I need. The belt it takes is a Melroe 6504510, a wide, internally cogged belt. Internet searches show dimensions and type info for all sorts of other belts but not this one.

Does anyone know of a place where I can ID this belt and what type it is, dimensions, etc. so I can start looking for the correct pulley halves?

And yes, I did try contacting the guy on You Tube, as have several other people, but he appears to have dropped off the face of the earth.

Good luck...

Many variable speed belts are custom made for the mfg, and they have to be right to work and last.

Not exactly sure how you are going to overcome the wallowed crank shaft, but if you can find a way to use a QD bushing, or Taperlok bushing, sometimes that will give enough squeeze to hold it on.

Here are some belts, but not sure if they are right. Any remnant of the old belt to measure?
Variable Speed Belts

Try calling the outfit linked below.
Belts

Do you have a link to that video?

From my understanding of these machines, these variable sheaves give it greater ground speeds. For your uses, do you "need" to keep the variable drive, or could you get by with a single-speed drive?

I saw one video that mentioned replacing the variable drive with the secondary drive from an old snowmobile. I know nothing about snowmobiles, but that might be another option for you.

Do you have a Gates belt & hose dealer nearby? Gates makes belts for just about every application known to man, and can almost certainly cross reference the Melroe part number for you.

(quoted from post at 12:34:52 03/29/17) Good luck...

Many variable speed belts are custom made for the mfg, and they have to be right to work and last.

Not exactly sure how you are going to overcome the wallowed crank shaft, but if you can find a way to use a QD bushing, or Taperlok bushing, sometimes that will give enough squeeze to hold it on.

Here are some belts, but not sure if they are right. Any remnant of the old belt to measure?
Variable Speed Belts

Click to expand...

The crank isn't wallowed Steve, the bore of the variable speed assy is. And yes, something like a Taperlock is what I had in mind. The belt isn't the problem, it's brand new a year or so back. 1 3/4" wide by 5/8" thick and the underside is cogged, not smooth. So what I'm trying to figure is what included angle the belt is designed to work at, ie- 40 degrees or what have you.

(quoted from post at 12:53:44 03/29/17) Do you have a link to that video?

From my understanding of these machines, these variable sheaves give it greater ground speeds. For your uses, do you "need" to keep the variable drive, or could you get by with a single-speed drive?

I saw one video that mentioned replacing the variable drive with the secondary drive from an old snowmobile. I know nothing about snowmobiles, but that might be another option for you.

Click to expand...

I don't need to go "fast", which on one of these is pretty slow. I just need to get things lined up and a single speed will be fine.

The video- https://www.youtube.com/watch?v=02sOlYG4_oM&index=2&list=FL1edOLZ-sldD00YIQiV_TWQ&t=187s

Looking the Taperlock bushings, they look like what the guy in the video used. Only thing is, the crankshaft on my engine isn't tapered. I assume theres a straight bore version of a split lock type bushing, but I don't know the name they are cataloged under. Help? :roll:

The taper is between the bushing and the pulley on a taperlock pulley, not between the bushing and the crankshaft.

You can get a bushing for whatever size shaft you have.

Find yourself a good power transmission house like Motion Industries, Kaman or Applied Industrial Technologies, they sell all kinds of this stuff. More than likely Melroe/Bobcat didn't make this stuff and the
PT houses sell parts from the PT manufacturer so you have to go through the Dealer network.

From my familiarity with snowmobiles, it sounds like what you are looking for is a centrifugal clutch. It has to be of course the right inside diameter, but it also has to have the correct engagement speed and the face of the inner sheave needs to line up with outer face of the secondary sheave when it is close to shifted out. I don't believe that the angle of the face is going to be a very big factor because that, from what I have seen, doesn't vary much from one application to another. You might try taking it to a snowmobile shop to see if it may match up with something that they have. Al's snowmobile parts in Newport VT would have hundreds of used ones.

Thanks guys, but no, I don't want a centrificul clutch. It's a skid steer, I already have clutches. What I want to do is use a taperlock type bushing (thanks for clearing me up on them Barnyard!) and sheave (found the proper spelling) halves that can be adjusted with spacers to get the right ratio for a useable single speed.