On a Hardinge VMC1000 spindle belt(2 double V-belt) make a loud noise when spindle start and stop.(WUUUU-WUUUU-WUUU or something like that)When speed is reached, everything is smooth. I changed the belt recently and noise go away for few hour and come back again. I try to reduce and increase tension but nothing to do! noise still there.

I cleaned pulley before instal new belt, i don't have tool to measure belt tension but i tried all setting from too loose to too tight. pulley seems to be in good condition. I realy don't know wath to do.

I thought pulley could be misaligned but there is no way to adjust pulley height.