V-Belt Question

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BearKiller
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First and Last Name: George Riley
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V-Belt Question

Post by BearKiller »

I have searched the internet for this answer to no avail.

My only-one-in-the-world Mitsubishi R2500 tractor has a loader that has it's own belt-driven hydraulic pump, completely independent of the tractors hydraulics.
The pulleys are A and B compatible.
I have been using an "A" belt (it was the only belt I had at the time that would fit), size 4L430 A-41.
I would like to use a 5L "B" belt.
I figure a "B" belt would need be longer, but how much longer?
I have very little adjustment.
It is a complete act of congress, requiring removal of the grille, radiator, tractor hydraulic pump, and the mounting bracket of the loader pump that this belt drives, just to get the belt on; otherwise, I would just buy several sizes and use the best option; however, I would like to avoid having to dismantle and reassemble the thing a dozen times.

What do you guys think; should I get a B-42 (one inch longer) or a B-43 (two inches longer) ?


Thanks for reading and all help is appreciated.

DaveKamp
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Re: V-Belt Question

Post by DaveKamp »

The A belt being narrower than a B, when you place the B in an A sheave, it will ride higher, thus, you'll need a longer belt. While belt manufacturers like Gates and Carlisle have drive engineer software, it all goes by sheave part number for their systems, so calculating a difference of length with two unknown sheaves will be very difficult... exactly how long will be best determined by trial-and-error.

Keep in mind that your Mitsu's sheaves were probably METRIC belt types, while the A and B belts are RMA standard (US Rubber Manufacturers Association) designs.

The RMA belt is a 32 degree included angle on the sheave and belt. OTH I don't recall what the ISO and DIN standards are, but I KNOW that there's variations, and of course, a different flavor of 'metric' for every country. :evil:

IF your A belt is fraying or experiencing wear or rubber transfer (to sheaves), it's most likely because the included angle of the sheaves is NOT 32 degrees... :roll:
Yes, I'm a Mad Scientist... but I'm usually happy, even when things ain't goin right.

BearKiller
Posts: 180
Joined: Wed Nov 07, 2012 12:27 am
First and Last Name: George Riley
Location: Poverty Springs KY 2018 Wettest State in the Nation

Re: V-Belt Question

Post by BearKiller »

DaveKamp wrote:The A belt being narrower than a B, when you place the B in an A sheave, it will ride higher, thus, you'll need a longer belt. While belt manufacturers like Gates and Carlisle have drive engineer software, it all goes by sheave part number for their systems, so calculating a difference of length with two unknown sheaves will be very difficult... exactly how long will be best determined by trial-and-error.

Keep in mind that your Mitsu's sheaves were probably METRIC belt types, while the A and B belts are RMA standard (US Rubber Manufacturers Association) designs.

The RMA belt is a 32 degree included angle on the sheave and belt. OTH I don't recall what the ISO and DIN standards are, but I KNOW that there's variations, and of course, a different flavor of 'metric' for every country. :evil:

IF your A belt is fraying or experiencing wear or rubber transfer (to sheaves), it's most likely because the included angle of the sheaves is NOT 32 degrees... :roll:
Thanks
I should have added that the loader is an American Kwik Way by K&W of Souix Falls, South Dakota.
I have since replaced the pulleys that came on it; in fact, the original pump shaft pulley stripped and buggered-up the shaft so badly that I replaced the pump with a beefier unit that had a larger shaft. I had to completely fabricate a new pump bracket.
I also replaced the drive pulley at the same time.
Both of these pulleys are standard 40-degree combination A or B pulleys.

I made a best guess and got a 5L440 / B41 belt on the way; it is an inch longer in outer circumference.

I wish there was some ring-on-the-horseshoes trick that would get the belt around the shaft without me having to do a major tear-down.
I got the bright idea that I would get four new belts; two generator belts and two hydraulic pump belts; install a new belt in each position and put the remaining new extras also on the shaft and zip-tie them out of harms way; my idea being that the next time I had to deal with a belt, all I would need do would be to release the extra new one from the zip-ties and route it around the pulleys.
Alas...., like so many of my brilliant ideas, when I investigated the possibility, everything is in such close quarters that things just barely clear as it is, with no free space to accommodate a couple extra belts.

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SWilliams
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Re: V-Belt Question

Post by SWilliams »

Go buy a B series adjustable belt and use it to make the correct belt length with the adjustments all the way in. Then measure that to get the correct size. Or buy a cheap B series belt and cut it and use it to measure.
Owner of an 1863, 2263 (1863 W 22hp engine!) 2084 and a 2 - 2284s.


"In God we trust, All others pay CASH..."

BearKiller
Posts: 180
Joined: Wed Nov 07, 2012 12:27 am
First and Last Name: George Riley
Location: Poverty Springs KY 2018 Wettest State in the Nation

Re: V-Belt Question

Post by BearKiller »

SWilliams wrote: buy a cheap B series belt and cut it and use it to measure.
Thanks ! That is an excellent idea !
I am going to screenshot that and put it in my belt information folder.

Back when I made the new pump brackets and had the thing apart and back together a hundred times, in a desperate attempt to keep from having to tear it down again, I got one of those linked belts that can be taken apart and put back together.
It didn't take long for me to see that they are more of a novelty than a usable belt; no matter how I tightened it, it slipped on the pulleys and got so hot that it melted itself apart.
There is still one hanging in the shop that I had forgotten about until your post.

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SWilliams
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Re: V-Belt Question

Post by SWilliams »

I've got a couple of the cheap link belt and a few good ones. The main reason they don't work is that they are really picky on the sheave angles and many are made to metric specifications while the CC parts are SAE. For making a belt though they are handy. I've got a few test belts on the wall. I just buy the cheapest long A/B/C widths and cut them. Then mark down the back in one inch segments. Biggest issue is usually when you have a tensioner. I pull the spring off or lock it in place a little shy of center so the belt can still stretch and flex.
Owner of an 1863, 2263 (1863 W 22hp engine!) 2084 and a 2 - 2284s.


"In God we trust, All others pay CASH..."

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