Fan belt life WAY too short!

[johndee138]

I just swapped my generator for an alternator. The mount yoke and pulley for the GM alt were purchased from Spadaro about 2 years ago. The belt I got recently from my local EV8 Ford parts seller. All the pulleys seem to line up nicely, belt tensions easily without binding. I leave about 1/2" to 1" play. Then in no time I have to re-tension the belt and Ive noticed black rubber dust all over the engine compartment and burnt rubber smells. Today I was out with the missus and it really started making a squeally racket. Lucky to have made it back home, Mama don't like gettin stranded. Upon inspection at home, the belt had turned itself outside in and was still on the sheaves but I could remove it by hand without any trouble. The pumps and alt were turning as the should but this wasn't gonna last like it should have. Almost all of the rubber had worn off, leaving the cloth fiber outer layer.
Could this belt, marked Ford 40-8620-A be a crappy offshore POS?
Is there a cogged belt that it can be replaced with?
Who has the good stuff?
Is there any good stuff to be had at all?
I'm trying to get this car ready for a couple hundred mile trip and this sort of foolishness doesn't lead to a very dependable feeling about taking it anywhere far afield.

[Ken Bull]

My thought is that one of the water pumps or the alt. are trying to kill the belt when they heat up???

[flatheadmurre]

Have in mind that your alternator probably has a higher output and therefor needs more power.
If that is combined with a smaller diameter pulley to get a higher rpm on the alternator you have added more stress to the belt in 2 ways.
When youre trying to transfer more power then the setup allows it starts slipping and wear out quick.

[51 MERC-CT]

Had an engine on a test stand with new alternator. Upon startup the belt was squealing. Turned out to be the alternator ( due to some electronic condition unknown to me ) that was causing it.
The alternator turned freely by hand and after tightening the belt it never did it again. Tighten the belt and disregard the tension play dimensions.
The belt is a NAPA product, not make-believe Ford.

[Karl Wolf]

Originally Posted by flatheadmurre

Have in mind that your alternator probably has a higher output and therefor needs more power.
If that is combined with a smaller diameter pulley to get a higher rpm on the alternator you have added more stress to the belt in 2 ways.
When youre trying to transfer more power then the setup allows it starts slipping and wear out quick.

As an addition to this previous thought, if you're running the bushing type water pumps, the pumps want a relaxed tension that conflicts with the needs of the alternator...

Karl

[4t8v8]

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I made my own mount for a 98 amp Chrysler alternator (the fins on it match my heads.)
Measured for the belt and went to an industrial supplier and got a Gates FHP belt. Been on there for 8 years and counting. Using the wide belt\pulley setup, of course.

[Lawson Cox]

Unless you are running everything stock Ford, a stock Ford belt is not going to work well. Measure what length belt you need, then go to a belt store. Fin

[flatford8]

Was that a NOS belt? Maybe it was dried out?....MARK

[G.M.]

Sounds like the belt was to loose. Staple some 100 sand paper on the end a
wood paint paddle and carefully remove the glaze from both sides of the belt.
Get a can of belt slip spray and give the belt a shot once in a while. Tighten so
there is a little less than 1/2 inch total play. New belts tend to stretch and may
need to be adjusted several times. G.M.

[rotorwrench]

Old belts break down quickly. Shelf life for the average belt is 5-years. Now if you put it in service with proper component function and tension it may last longer than 5-years but I've noticed that old stock belts sometimes won't last through the break in period.

As was mentioned previously, you may have an alternator problem. If the alternator doesn't start charging at low rpm, it can get a higher than normal output load when it does start. By then the battery charge level can give it a run for its money causing the belt to slip. An alternator problem can ruin a belt quickly too. A bad diode bridge or an internal regulator problem (with single wire alts) can cause it to lock up when it tries to start.

[39portlander]

[QUOTE=johndee138;1170687]I just swapped my generator for an alternator. The mount yoke and pulley for the GM alt were purchased from Spadaro about 2 years ago.

There is the problem, a GM alternator. On a serious note, I have a Ford one wire Alt and bracket from Certified auto electric in Ohio. Have a NAPA B53 on there, using a straight edge to get everything squared up. They did ask about motor and water pump sheave dimensions, so the proper alternator sheave was chosen and installed.

I do HVAC and have to align a lot of belt/sheaves, out of alignment or very old customer belts leave the rubber dust trail. Good luck

[19Fordy]

39; Looks very nice.