[Richard Curtis]

I've read that the slack in the alternator and fan belts should be about a quarter inch (I'm trying to find the Gates belt tension gauge to get it absolutely correct) but can find no mention of desired tension/slack on the a/c belt. Mine seems to have about a half inch of slack. Any guidance?

[Marc A]

Rule of thumb on fan (V) belts is no more than 1/2" deflection at the mid-point between pullys.

[Richard Curtis]

Okay. But is this true for the air conditioning compressor belt also? Thanks for your prompt reply.

[Marc A]

If you have 1/2" belt won't fly off and bearings won't fry. While running the car with the A/C on go look at the belt. If you can see the belt moving off line (bouncing) at the midpoint then tighten abit.

Lots of imperical information here . . . .

[Jase007]

Been doing this for years. Don't know if this applies to all belts but my process ... grab belt (when NOT moving ) between thumb and 1st finger and rotate to 90 degrees. If can rotate more = too loose, less = too tight. Works on BMWs, Ferds, P-cars, etc... and plenty of other cars (v-type belts, including G body fan belts). Definetly NOT scientific and is also a "feel" thing ... like adjusting valves

Does NOT work on single sepentine belts (ala GMC P-car haulers) or tensioned timing belts (ala Honda, BMW).

Jase

[matt de maria]

You can get the belt tension gauge through Kent-Moore (29784 Little Mack, Roseville, Mi. 48066-2200) P/N on box is GA-424-A. P/n on tool is BT-33-73F. Used AC belt calls for 105 lbs tension.

[Richard Curtis]

Replaced all three belts today; took about an hour, most of it spent wrestling with the a/c compressor and hunting dropped washers. Thank goodness for a magnet-on-a-stick. Without the Gates tension gauge, I simply installed the belts with about a quarter-inch of slack at the midpoint on all three. This also works out to be the same as being able to turn the belts about 90 degrees. (Also a lesson learned while doing enduro kart racing for 16 years! In karting, more damage could be done from a belt that's too tight than one that's too loose. Assume same applies to V-belts.)

[markwemple]

I also use the 90 degree check and have never had a problem.

[Richard Curtis]

Opened the C2's hood today to show off my handiwork to my visiting son (he was impressed) only to find the alternator belt lying there, broken clean through (he quickly became less impressed). This is a brand-new belt; simply snapped. it must've happened Friday morning when I was moving cars around, because the car ran perfectly Thursday to and from work and the alternator light never came on (I assume the light comes on if the alternator belt breaks). Could I have tightened it too much? Maybe add one spacer?

[Richard Curtis]

Opened the C2's hood today to show off my handiwork to my visiting son (he was impressed) only to find the alternator belt lying there, broken clean through (he quickly became less impressed). This is a brand-new belt; simply snapped. it must've happened Friday morning when I was moving cars around, because the car ran perfectly Thursday to and from work and the alternator light never came on (I assume the light comes on if the alternator belt breaks). Could I have tightened it too much? Maybe add one spacer?