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Discussion Starter · #1 · (Edited)
Short version: can't keep alternator belts from squealing at low RPM's and on acceleration. Can't keep them from snapping and/or flying off whole (not exactly sure which is occurring other than the belt is clearly leaving the trike one way or another).
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Long version below, if you want the details:

My 2001 Boss Hoss trike has been down for a number of reasons since July or August. I finally got it back on the road today for a few test runs. Discovered it's eating alternator belts left and right (3 today). The belt I keep replacing is a V-Belt 7315 aka 15315 3/8" x 32-1/8" OC (10mm x 815 mm OC). I've tried MasterPro and Duralast. I have one extra Duralast and one Drive Rite on hand.

Each time I put on a new belt it squeals, almost always at low RPM's, but sometimes at higher RPM's too. The belts keep letting go at highway speeds under acceleration, around 70 MPH (not sure about the RPM's, but I'd say around 3000 and up). When this happens my battery/voltmeter gauge instantly sinks from 14V to around 11.5V. That's how I know the belt has cut loose. I pull over, and sure enough, nothing there.

Visually, I cannot see any defects in the chrome alternator adjustment bracket. No cracks, as far as I can tell with it on the trike. I pried left and right and back to front on the alternator body, to see whether there is any movement in the bracket, but it's solid. The trike rocks back and forth and left to right, but the alternator doesn't move.

I tried scuffing the alternator pulley wheel with sandpaper to help the surface grip the belt a little better.

I also used a hydraulic floor jack, offset a little, to push on the alternator body while installing the V-belt, in order to reduce as much deflection as I could. The alternator pulley and the main crankshaft pulley have only about 4" of distance between them, so as far as I know, the belt should have nearly no deflection at all, if any. Unless I'm mistaken, the (old?) general rule of thumb is 1/4" deflection for every 12" of distance between pulleys? I can't remember, honestly. Don't know if anyone goes by that anymore.

I bumped the engine a few times with the choke on, to watch the main pulley. It appears to have a subtle warp, but I cannot honestly tell whether that's just the way it came from the factory (normal?) because it's so subtle (no glaringly obvious/abrupt warp). Doesn't look like there's any real back and forth movement in it. Kind of like watching brand new vinyl on a turntable, for those of you who remember. With those things there's no such animal as perfectly and flawlessly 100% flat. Don't know if that's the case with crankshaft pulleys? Any of them 100% flawlessly flat, or is there a tiny bit of warp (not wobble) in them?

The crank pulley and the alternator pulley appear to be aligned properly when the belt is on.

This mysterious belt-slinging just started happening after getting the Hoss back on the road after a 2 to 4-ish month sit between an armload of minor repairs (mostly electrical).

Right now I'm wondering if I'm just not putting enough tension on the belt? Mighty hard to do by myself. Or is something else likely wrong?

Thank you for your suggestions, Paul H.

Tossing this out there to see if anyone else has been visited by the alternator belt eating monster in the past, and what resolved your issue?

I've been pouring through threads, but haven't found this specific issue yet. Alternator belt squealing and slinging 101...

Thank you.
 

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belt

try a smaller width belt and make sure that it fits securely within the pulley valley
Buck
 

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Discussion Starter · #4 ·
Is it definitely the belt squealing or could it be the alternator itself?
Pretty sure it's the belt, as the squeal is intermittent. Usually the worst at idle, then it stops once I get moving. Starts again for a few seconds if I goose the throttle. Gets quieter the more tension I'm able to put on the belt, but it's tough to get enough leverage.

try a smaller width belt and make sure that it fits securely within the pulley valley
Buck
I immediately noticed when I put on the latest belt (a Duralast) that the top of the belt sits about 1/8" below the outer edges of the crank pulley. The other belts sat flush with the edges (different brands, as each store carried only one belt; I went to a handful of stores). I haven't run this one yet. Will try it out on the way to work. If it holds, I'll order a few extra. Will dig around and see if they make any more narrow, just in case.

Thank you
 

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Discussion Starter · #5 ·
So far it seems to enjoy the Duralast belt (from Autozone, I think). Nice and narrow and tucks into the valleys well. Didn't hear a bit of squeal this morning at any time. I didn't think to see if was still on the trike when I arrived at work, but the volts were at 14 when I shut it down, so it's a safe bet to say the belt is still there.
 

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Short version: can't keep alternator belts from squealing at low RPM's and on acceleration. Can't keep them from snapping and/or flying off whole (not exactly sure which is occurring other than the belt is clearly leaving the trike one way or another).
...


Long version below, if you want the details:

My 2001 Boss Hoss trike has been down for a number of reasons since July or August. I finally got it back on the road today for a few test runs. Discovered it's eating alternator belts left and right (3 today). The belt I keep replacing is a V-Belt 7315 aka 15315 3/8" x 32-1/8" OC (10mm x 815 mm OC). I've tried MasterPro and Duralast. I have one extra Duralast and one Drive Rite on hand.

Each time I put on a new belt it squeals, almost always at low RPM's, but sometimes at higher RPM's too. The belts keep letting go at highway speeds under acceleration, around 70 MPH (not sure about the RPM's, but I'd say around 3000 and up). When this happens my battery/voltmeter gauge instantly sinks from 14V to around 11.5V. That's how I know the belt has cut loose. I pull over, and sure enough, nothing there.

Visually, I cannot see any defects in the chrome alternator adjustment bracket. No cracks, as far as I can tell with it on the trike. I pried left and right and back to front on the alternator body, to see whether there is any movement in the bracket, but it's solid. The trike rocks back and forth and left to right, but the alternator doesn't move.

I tried scuffing the alternator pulley wheel with sandpaper to help the surface grip the belt a little better.

I also used a hydraulic floor jack, offset a little, to push on the alternator body while installing the V-belt, in order to reduce as much deflection as I could. The alternator pulley and the main crankshaft pulley have only about 4" of distance between them, so as far as I know, the belt should have nearly no deflection at all, if any. Unless I'm mistaken, the (old?) general rule of thumb is 1/4" deflection for every 12" of distance between pulleys? I can't remember, honestly. Don't know if anyone goes by that anymore.

I bumped the engine a few times with the choke on, to watch the main pulley. It appears to have a subtle warp, but I cannot honestly tell whether that's just the way it came from the factory (normal?) because it's so subtle (no glaringly obvious/abrupt warp). Doesn't look like there's any real back and forth movement in it. Kind of like watching brand new vinyl on a turntable, for those of you who remember. With those things there's no such animal as perfectly and flawlessly 100% flat. Don't know if that's the case with crankshaft pulleys? Any of them 100% flawlessly flat, or is there a tiny bit of warp (not wobble) in them?

The crank pulley and the alternator pulley appear to be aligned properly when the belt is on.

This mysterious belt-slinging just started happening after getting the Hoss back on the road after a 2 to 4-ish month sit between an armload of minor repairs (mostly electrical).

Right now I'm wondering if I'm just not putting enough tension on the belt? Mighty hard to do by myself. Or is something else likely wrong?

Thank you for your suggestions, Paul H.

Tossing this out there to see if anyone else has been visited by the alternator belt eating monster in the past, and what resolved your issue?

I've been pouring through threads, but haven't found this specific issue yet. Alternator belt squealing and slinging 101...

Thank you.
wow, SAME problems here. at this time i am living with the pig squeal while working another issue
 
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