mci fan belts, what causes them to roll?

[christopher]

Once in a while my a fanbelt will roll?
any know why?
Thanks
Chris
MCI 5C

[Dave5Cs]

Your air adjuster may have a leak or not adjusted properly. Look in DA Book and it will tell you how to do it.

Dave

[lostagain]

Also if the pulley is worn and the belt rides down onto the bottom, that will make it roll. Make sure the belt is off the bottom of the pulley, it should ride on the sides of the V without touching the bottom. Some pulleys are adjustable, or you need a bigger belt. 

JC

[eagle19952]

GO to a Gates belt distributer and GET a pulley and belt wear gage. Cost about 3$-4$ and will allow you to SEE what is really going on with your pulleys, including if the drive and drivens are even the same...don't ask how I know this.

Belt & Pulley Gauges

 
Item Code - 7401-0015
Gates colour coded belt and pulley gauges detect worn pulleys and identify belt cross sections. The pulley gauges fit standard industrial grooves, identifying excessive wear before it leads to premature belt failure. The belt gauges can also be used to identify belt cross sections when labels have been worn away. All grouped together on a sturdy chain, the gauges will be a valuable tool to any fitter.

[Gary '79 5C]

Also make sure the centerline of each pulley is inline. You can place a straight edge across the face of the pulleys to make sure the belts are running true. I can not imagine one pulley walked on the shaft, but if you had you mitre box replaced/rebuilt the alignment may be out.

I see this with belt driven fans, etc.

[Busted Knuckle]

I've also seen where an engine cradle slid back and gotten them out of alignment!
(NO IF PROPERLY SECURED IT SHOULDN'T!  But I saw one that did!)
  BK