Poly V belt being squeezed

debit · Post by **debit** » Sat Jun 18, 2011 1:53 pm

While troubleshooting a squeeling sound and smell problem I realized that the Poly V belt is being squeezed and wrinkled between the Poly V sheave and the frame as the speed is slowed. It seems this Poly V sheave should be stationary so the control sheave has something to press against as the speed is slowed. Is this correct? If so what or how to I remedy this? Any ideas? Thanks.

beeg · Post by **beeg** » Sat Jun 18, 2011 2:13 pm

How OFTEN do ya lube it?

billmayo · Post by **billmayo** » Sat Jun 18, 2011 2:29 pm

debit wrote:While troubleshooting a squeeling sound and smell problem I realized that the Poly V belt is being squeezed and wrinkled between the Poly V sheave and the frame as the speed is slowed. It seems this Poly V sheave should be stationary so the control sheave has something to press against as the speed is slowed. Is this correct? If so what or how to I remedy this? Any ideas? Thanks.

A common problem that I find. I would start by removing the belt housing and seeing if the idler shaft (bottom shaft) is moving out of the headstock when the rubbing begins. I use a larger body washer to keep the eccentric bushing and idler shaft bearing from moving outward from the headstock. If no movement, then watch the Drive Sleeve shaft (upper shaft) to see if it is moving. Anyway, watch the Poly-V belt as you change speed to see what is moving. If the Poly-V belt is too loose, then the belt may be switching grooves (only saw one of these) as the speed changes. This is normally because the Poly-V belt is misaligned when it was installed.

debit · Post by **debit** » Wed Jun 22, 2011 2:57 pm

Thank you, Billmayo, that was the problem! The washer worked just great. Now after removing, cleaning and recalibrating the speed changer, the speed changes much easier and without the smell. During the exam of the speed changer I see where the worm control shaft is slightly bent so I will be replacing that and the quadrant assembly (couple chipped teeth). Closer exam of the belts revealed that they (Poly V and drive) should be replaced which should eliminate the squeeling (re-tensioning didn't help that much). Thank you very much for your help.