my 3.2 1986 eats belts

[ISpeed2day]

okay so i have a 1986 3.2 carrera motor and it eats alternator belts. Ate one last fall on a hot day (over 90) and ate one today (over 90)

didnt break the outer loop but tore all the teeth off in large groups.. looks like both sides of the belt where shaved by something.... what gives?

Thanks in advance oh guru's of the H-6 motors...

[dtw]

I'd check the crank pulley very carefully for any bends/burrs/misc. damage that could be eating the belt. Same on the alternator pulley. If those check out, have you been checking the tension on the belts after they are broken-in? They loosen up after several hundred miles and should be re-tensioned.

[Flieger]

Sounds like it's too tight. You are familiar with the split-pulley design where the tension is adjusted by moving shim washers to vary the width of the pulley. At the higher tension settings, the pulley is narrow and may rub on the sides more.

[ISpeed2day]

I did order more shims with the new belts.

I do know that the pulleys are both clear and smooth. This motor was on a stand last summer.

I think perhaps the tension could be too much, then apply heat and high revs and poof. I just wanted someone else to say that might be it.

Anyone else agree?

[Mr9146]

What size belt are you using?

Also, you should have a total of 5 shims ... 6 max.

[dtw]

Originally Posted by Mr9146

What size belt are you using?

Also, you should have a total of 5 shims ... 6 max.

There should ALWAYS be six - never less.

[Mr9146]

Originally Posted by dtw

There should ALWAYS be six - never less.

Is it 6? I can't remember anymore ... it's hot.

[ISpeed2day]

when i got the old shims out I could see there were 7 and they were two different sizes. I replaced them with all new ones. Hopefully I will be good now for a while.

[KTL]

The shim total thickness is the critical thing. If you've got a total of 7 and they're of acceptable thickness, you should be fine. The key is of course how they're arranged on the alt. shaft. If you've got too few between the pulley and fan, your belt is going to be too tight.

So check the belt tension when you install a new belt, after you turn th engine over a few times to seat the belt uniformly. Push on the belt perpendicular to the belt length at midspan (1/2 way between the bottom of fan pulley and top of crankshaft pulley). It should not be difficult to displace the belt and you should have around 1/4" to 3/8" displacement for good tension.

[billybek]

I agree with looking carefully at the pulley. If they have been worn from slipping, the "Vee" will become a channel with square sides. This will actually suck the belt in at the bottom and rip chunks out of them...
I really don't like notched belts. They seem to stretch more, compounding pulley wear problems.
Put a straight edge across the surface of the pulley, if you see they are significantly dished, replace them.

[dentist90]

Sounds like the belt may be too tight. Also, could the pulleys not be aligned properly?

[ISpeed2day]

like I said, new shims seems ok now, tension is good now, shims all same. agree that ribbed belts may suck, does OEM belt have ribs too.