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Guest Message by DevFuse

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Belt breakage?

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7 replies to this topic

#1 markjs


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Posted 21 April 2018 - 06:17 AM

I have an '84 GL Wagon, no frills one belt, that runs both water pump and alteranator.  Though I can find no misalignment with a straight edge, I have now broken two V-belts.  The first one *may* have been too tight, but I used the 90 degree twist both times, and the first one lasted like 5 minutes, the second several hyndred miles.  Thge second started squealing recently but I KNOW it was not too tight, if anything slightly too loose, any ideas as to why this is happening?  It's really a huge flaw as it only has the one belt.  There are two pulleys on the crankshaft, and I seem to remember my last '84GL having two bults that turned the water pump but don't recall for certain?

#2 DaveT


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Posted 21 April 2018 - 09:38 AM

What is this 90 degrees twist? Never heard of it.

Squealing is caused by too loose.

Cars with power steering and or a/c would use 2 belts.

#3 Subaru Scott

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Posted 21 April 2018 - 09:39 AM

Sounds like alternator or water pump has a bad bearing.

#4 lrgvanman


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Posted 21 April 2018 - 09:47 AM

My '84 has no A/C and has an EA81 running only one belt. Belts that squeal end up glazing and therefore require a ridiculous tension to end the squealing. My '87 did that until I replaced the belt. Too tight is usually done with a three-foot-long bar or something of the likes. There is a belt deflection measurement but I forgot just what the requirement is and I personally have tightened the alternator belt where I could not turn the alternator with the push of my thumb on a fin and it has worked. Dual belts on your unit? Check with a reliable parts man and see if it is listed as so. I don't know what would cause them to break like that though. Subaru Scott suggested possible bad bearing and that sounds like a very good possibility. Good luck.

Edited by lrgvanman, 21 April 2018 - 09:55 AM.

#5 jono


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Posted 21 April 2018 - 04:46 PM

Same brand belt each time? Can you take issue up with supplier? That crank pulley you may find looms like twin belt drive but is actually likely what I have - three! One smaller in the middle so PS and ac can be driven as well as alt and wp.

A bar of dry hand soap held carefully against both sides of belt can give temporary noise relief.

I like to be able to get half belt depth defection when finger push on longest stretch so not to strain wp or alt bearings

#6 jono


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Posted 21 April 2018 - 04:46 PM

10A 12A or 13A wide belt in use?

#7 idosubaru


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Posted 21 April 2018 - 08:10 PM

Are the belts old and used? Rubber degrades and easily breaks with only a few years age depending on light, temp swings, storage, etc.

How old was the last belt that broke?
Brand and age of “new” belt?

Remove belt and spin pulleys by hand - if there’s tightness or noise or okay that’s your issue.

Is the crank pulley separated and misaligned conventrically?

#8 djellum


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Posted 23 April 2018 - 12:15 AM

belt too wide?  belts should sit completely inside the pully, but not too deep.  flush with the outer diameter of the pulley or showing outside of the pulley is too large.  it reduces your surface contact and prevents it from getting a grip.  some belts are too tall as well, so they may contact the inner edge of the pulley.  need to get the sides in play.


once a belt squeels any signifigant amount you should clean the pulley.  wire brush is generally enough but you might try some cleaner as well.  gets buildup there.


ive also had pulleys put back on backwards on the water pumps and such that make it just a little out of alightment.  also maybe lost a spacer behind a pulley?


check alternator mounts and condition of water pump and alt shaft to see if they are moving during operation.


if 90 deg twist means the belt twists between 2 pulleys dont do that.  should be a nice smooth circle.

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