With the Fan Belt Toss in the rearview mirror, what better tech topic to discuss than Fan Belt Maintenance so you don’t toss, or better, throw your belt.
Courtesy of Mike Dawson and the Central PA Corvair Club
FAN BELT MAINTENANCE
The Corvair boasted a specially designed belt that G.M. used only after rejecting at least four different designs. Since G.M. discontinued the original design years ago, no other company has duplicated it exactly – I kept an original and compared all of the reproductions. Some are close but not exact. Anybody can have good luck with a $5.00 belt, but if you want one close to the original, use a 3V560 wrapped, industrial belt. The original belt was 55 3/4″ x 3/8″. The 3V560 belts are sold by most Corvair vendors as “super belts”; the Gates and the Bando belts work great on any Corvair with the correct items as noted here. (Here is a link for Clark’s who sells their belt made specifically for your Corvair.)
INSTALLATION CHECKS
Drive pulley or balancer should be checked for rust, wobble or separation and the timing notch checked for a sharp edge that can wear the belt. Idler pulley should be checked for rust, wobble and dents caused by pry bars. The big washer on the slide end of the bracket must be between the nut and the slide, not between the slide and the casting. Check fan pulley for rust, wobble and dents and most important for proper height. On the car reference: lay a straight edge across the top of the pulley, measure down to the shroud next to the choke rod (intake flange) on the left side. It should measure exactly 6″ for 62-69 and 6 5/32″ on original 60-61. This dimension will be wrong if you fan bearing was installed incorrectly or if it has moved in the top cover where it should be an interference fit.
Alternator/generator checks
The pulley must be exactly 3″ O.D. Rebuilders change them and even a 1/4″ size difference will change belt alignment. Look for a loose generator mount on the left end, check for the proper alternator/generator adapter. As with other pulleys, check for rust, dents, wobble and wear.
BELT TENSION
There should be a 3/8″ deflection with a 15# load between the idler and the fan. The book calls for 55# if you have a strand tension gauge. You can barely turn the alt/gen fan with your thumb when correctly tensioned. Tension should be checked after a break in period.
BELT GUIDES
The rear guide can easily be installed on any year; the top guide should be in place on any that have the mount holes in the top shroud. Clearance between belt and guide is 1/16″.
If the GEN/FAN light comes on, stop ASAP. Determine if the belt is working or not. If it is, you can drive the car but have the charging system checked as soon as possible. If it is off, replace it before driving. Once a belt comes off, the cords are bent, and it continue to flip.
If you must drive, follow the owner’s guide instructions for operation without a belt. (Short drives with the heater fan on high) NEVER drive a Corvair with the TEMP/PRESS light is on; you are already at 550+ degrees. Remember, if you ruin an engine by overheating, it probably cannot be rebuilt due to softened aluminum in the heads and crankcase.
*SFBA Note: On top of carrying a spare fan belt, every Corvair owner should have this handy wrench sold by Clarks. Not only will it cut your time down on a belt change, it is very handy for removing carbs and disconnecting battery terminals.
Have a fan belt tip? Something we missed? Let us know in the comments!
SFBA CORSA 
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