Jamer
Guest
I'm assuming that you've adjusted the inner jam nuts and also when the new style fan was installed the person went ahead and installed the new driven pulley set that came in the kit. Check to make sure that the fan speed sensor is set close to the reluctor on the left side of the fan shaft. This will ensure that your instrumentation is reading correctly unless, of course the sensor is bad. After you check that, then check for wear at the fan jackshaft hub. If the keyway and key start to wear this will slow down your potential fan speed dramatically. To check for wear, unhook your six-sided belt, driven belt and drive belt from their pulleys on the jackshaft and see if you can wiggle the shaft side to side or in and out.