dtmcnamara

really the only time UD pulleys are bad are when you have a 4cyl engine. When you have an engine this small its hard to keep the engine balanced. Now with the bigger engine it will not hurt it as bad. Many people say over time it will mess things up, but whos going to keep there same mustang for 500,000 miles. Now lets see.....no one, so unless your going to run your car for half a million miles get the UD pulleys, or unless you have a 4 cyl mustang, then you just need to get gone.

Deannostang

Underdrive pulleys are no problem whatsoever. I have had them on for over two years and all has been perfect with the altenator, air, water flow, etc. No squeeks either. You should definitely use a new Ford serpentine belt when you put them on so all is up to specs. As far a voiding your warranty, I am not too sure about that. Ford Racing even sells a complete underpulley kit for Mustangs that I believe you can order directly through your Ford dealer. Can't see how this would be a problem. I do also use a 180 degree thermostat that was recommended by Steeda. This is kind of a double defense against overheating with the reduced rpm the pulleys create. The temp always runs just right with no high readings in the summer or problems with heat in the colder months. By the way, I use the March black pulleys on mine. Good product. They probably make most of them for other suppliers as well.

josh_0351

I've got Steeda non-piggyback's. Are your March's piggybacks?

Deannostang

Yes, they are, piggy back that is. They didn't offer the other part until I had already had them installed. No sweat with that though. No squeeking, buzzing, rattling, uneven belt wear or any of that kind of stuff. I did pay to have them installed along with a new Ford belt at the same time. I wanted them installed so all the torque settings and alignments were perfect. Not one problem so far. March has probably been around in this business longer than anyone else. Good product.

badass04gt

I found out that if you use ford performance parts, it will not void your warranty. Any other brands will though.

Deannostang

Most all Ford perfomance parts are made by the same aftermarket suppliers. Go figure? K&N even makes a "blue" high flow air filter with the Ford name on it for the Cobra "R". I bet someone like March makes the underdrive pulleys for Ford. Only difference is the color. The "fit" is what is suspect with non Ford parts. Ford makes sure everything it offers bolts-on directly as did the original equipment.

Fat Nick

Actually the Steeda's are used by Ford. But around here they were selling "hopped-up" GT's with Steeda's on them already and full factory warranty. I ran into the UD problem with my dealership, all I did was play stupid and explain to them I bought it like that, which in my case was believable since it was a demo from another dealership.

stanglover03

You said you put on a new factory belt when you put your pulleys on. Is that something I should do and why so?

neogenic83

if anything they would make your accessories last longer since they are being driven at a lower speed

wangdoodle1740

I've got a set of UD pulleys on my car. Everything works just fine for me, temp is right where it always is, no squealing. Hell the dealership didn't even realize they were on there when I took it in!

Kenny