Generator belt being eaten....

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investig8
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Generator belt being eaten....

Post by investig8 »

Good Morning All,
The two or three times I have taken Fiona out for a drive, I could smell rubber burning. After this morning's drive I looked her over good and found that the generator belt (new) is being eaten, leaving a heavy coating of rubber "dust" over the entire area below the pulley. The generator appears to be charging, but was wondering if I have a pulley issue or a generator issue? Any thoughts??
thanks,
Dennis
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Re: Generator belt being eaten....

Post by Elwood »

Are the pulleys in line and turning in the same plane?
“When a long train of abuses and usurpations, pursuing invariably the same Object evinces a design to reduce them under absolute Despotism, IT IS THEIR RIGHT, IT IS THEIR DUTY, TO THROW OFF SUCH GOVERNMENT...” -Declaration of Independence, 1776
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Re: Generator belt being eaten....

Post by vit16 »

misalignment or maybe an incorrect belt type could be the issue
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Re: Generator belt being eaten....

Post by NAM VET »

can you lay a straight edge across the pulleys, to be sure they are lined up, ie, parallel with each other an not misaligned. Can you turn easily the alternator pulley and water pump pulleys by hand? Hal. aka NV
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Re: Generator belt being eaten....

Post by m-37Bruce »

Tension?
Bruce,

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Re: Generator belt being eaten....

Post by Cal_Gary »

The belt could be too narrow, and bottoming out in the pulleys. I have that to a lesser degree with mine-much squealing but no dust. I did purchase an M37 pulley to go on my alternator whenever I get around to making the swap. Once done, with a new M37 belt should solve the problem.

Let us know what you find-thanks!
Gary
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Re: Generator belt being eaten....

Post by NAM VET »

maybe the above suggestions are right on. Could the two pulley's be non-military original, and thus not fit the belt? And the belt be riding in the bottom of the groove? Two different pulley groove specifications? I think you will fin the issue quickly. Hal
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Re: Generator belt being eaten....

Post by investig8 »

Thanks guys for your help... It appears that I may have a couple of issues. First, the three pulleys all seem to line up just fine, so I don't think alignment is an issue. The water pump pulley definitely has a small dent in it and the shaft has a very, very small amount of wobble to it. Those I will replace. However, the belt runs true on the water pump and crankshaft pullies with no contact with the bottom of the pulley. On the generator pulley however, the belt seems to be in contact with the bottom of the pulley. The belt was purchased new from Vintage so I believe it is the correct one. I'm guessing I need to replace the generator pulley as well?
Thanks again for your assistance,
Dennis
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Re: Generator belt - UPDATE

Post by investig8 »

OK gentlemen... I found the fan belt was narrower than a N.O.S. one I ordered from Vintage so that is the most likely problem to the wearing away of the belt. It was riding in the bottom of the generator pully. Now, for a second question... The generator won't stay tight, which adds to the problem, obviously. I can't seem to get anything on the bottom two bolts other than a wrench which has very limited travel... Short of taking off the inner fender panel, any ideas on what I can use to tighten those bolts?
thanks,
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Re: Generator belt being eaten....

Post by Cal_Gary »

Ok on the narrow belt (chalk one up to Gary!)
Can you get a ratchet wrench on the bolt heads? If not, how about a 1/4 drive socket? They're thinner than a 3/8 or 1/2 socket, with very close ratchet teeth so it doesn't take much to get them moving.
Just my thoughts,
Gary
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Re: Generator belt being eaten....

Post by NAM VET »

My 37 has the four belt, 100 amp alternator, and the bolts holding it in place are not hard to get to, so I don't know what it takes to do a 25 amp generator. But for some tight spaces in the past on vehicles, I have had to grind down wrenches, or cut some some of the 12 point box wrenches to open them, or locate some extra short socket. And I usually have to hold some sort of long bar with my forehead or chin to hold the alternator snug while I fiddle with tightening the fasteners. Maybe if you can have some one help out with this project, you can get it tight enough.

I would think that when these vehicles were engineered, they would have made it relatively simple to accomplish routine maintenance with simple tools. Is your bracket system some non-oem part? As above, sometimes a 72 tooth ratchet is a lifesaver. Or one no teeth, but some sort of cam gear so it can accomplish turning a fastener with very little arc. Look over the MAC tool catalogue and see if you can find what you need.

hope this works out soon to get you back on the road. Hal
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Re: Generator belt being eaten....

Post by John Mc »

I've got an alternator as well, but my recollection is that when replacing the belt, from the top, I was able to reach one end of the lower bolt with a box wrench, and on the other I used a socket with an extension to get the handle out from under things where I had the room to swing it. I found that no "wobble socket" or u-joint was necessary on the ratchet.
Last edited by John Mc on Thu Sep 02, 2021 8:46 am, edited 1 time in total.
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investig8
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Re: Generator belt being eaten....

Post by investig8 »

Thanks for all the responses, you guys are like Google, you know everything!

I finally resolved myself to crawling under Fiona and removing the metal splash panel directly under the generator and was able to get a good box-end wrench on both bolts. Tightened them and the adjustment bolt on the topside and it seems my problem is no longer a problem.
Thanks again,
Dennis
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Re: Generator belt being eaten....

Post by Cal_Gary »

Well done!
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Re: Generator belt being eaten....

Post by investig8 »

Hello All,
An update on my generator belt saga... I drove her to a car show two weeks ago and once again, destroyed the fan belt during the short drive (less than 15 miles).
Tore into it this past week and found the generator pully was heavily pitted on the inside surface (where the belt runs). I replaced the generator pulley and decided while I was there to replace the water pump and pulley as well. Finished her up yesterday and took her out for a short drive. Good News!! I found the belt still tight and no evidence of it being eaten... I believe we have solved the problem.
Thanks again for all who provided me a little guidance,
Dennis
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