Underdrive pulley/harmonic balancer Q.

[jastang]

Installing an underdrive crank pulley on '97 GT. Obviously the diameter of the new pulley is much smaller, but the weight is also significantly less. I cannot tell if there is any counterbalance in it at all or if there is meant to be. I assume that the big, heavy stocker is counterbalanced.

So, key question. Do I need any additional balancing on the crank pulley or is this small, lightweight pulley the only thing meant to be installed?

 

[jtb19nh]

what pulleys did you get? Is it a piggyback set up or a 1 piece?????

 

[jastang]

It's just one piece, no elastomer band or anything. From what I understand though, the 4.6 crank is internally balanced, so it doesn't have a counterweight, just a damper if anything. I don't think my pulley has any dampening qualities, but it's installed and I noticed no increased vibration and it gets off the line a bit quicker.

 

[trinity_gt]

You won't notice any additional vibrations because the vibrations the damper is designed to deal with are miniscule in magnitude. The problem is that to the oil pump gears and timing wheel (behind the front cover) such vibrations are serious and can lead to fractures of the metal and failure. I don't think it's a common occurence and probably occurs on high-RPM road race engines but I also know the 4.6 is susceptible to oil pump gear failures when a non-factory damper significantly different from the factory piece is used.

UDPs that fail to preserve the characteristics of the factory damper are placing the OEM gears and timing wheel (the powdered metal unit and eariler 4.6s) at risk.

 

[dmenard74]

I have a set of steed underdrive pulleys that I will be putting on tomorrow. Does anyone know if the steeda crank pulley a piggy back or balanced??

 

[jtb19nh]

im pretty sure the steeda is a one piece!!!

 

[95GTV8]

from what i've heard about the piggy back pulley issue steedas are 1 piece (no piggy-back required). I've heard that most March pulleys are piggy-back and other manufactures it is best to check, if the website doens't list it, call the seller or call the manufacturer. It's not an issue on the 5.0 (which i have) but i've heard some horror stories about people who purchased piggy-back pullies, but didn't piggy back them. I don't know if the stories hold any merit, but it's better to be safe than sorry. GL with the pulleys!