I just got my asp underdrive pulley installed on my 5.3l. The install went great i got the longer ARP bolt on there and everything. The truck runs great, but what is happening is that i hear like a little whine noise at idle and when i take off from a dig. It almost sounds like alternator whine, i noticed that my voltage shot up when i installed as well. Any suggestions re tune? idk..

 

wait u have the UD crank pulley only right? did you do the over drive ALT pulley?
were the belts in all the grooves? it sounds like your off 1 groove or the tensioners are going bad

 

yup i have the UD crank pulley, nope i dont have the over drive ALT but i have the underdrive ALT that i have not installed yet.

 

so wait u bought 2 main drive belts?
i sounds like a tensioner or idler pulley

 

yes sir i have the correct belts on it as well. I got no clue why this is going on, it bugging me. Im going to mess with it tomorrow.

 

if you installed an underdrive pulley, i have absolutely no idea why your voltmeter is spiking higher than normal. i'd suggest that you hook a multimeter up to the output of the alternator and test what you're getting. does the whine come from inside the cab or under the hood

 

The belt was the problem guys. All i did was buy a new one and it fixed the whine. The original belt that i had got had a different style grove and that is what was making the noise.