BBK15550 Underdrive Performance Pulley Kit - CNC Machined Aluminum 8-Rib for Ford F Series Truck, Expedition 4.6L, 5.4L - 3 Piece

Installed on a 2000 EB Expedition with 5.4L engine. Installation wasn't overly difficult. Some specialized tools will be needed for the crank pulley. The hardest part for me was getting the crank pulley bolt out. I didn't have an impact wrench and finding one which fit the space between the bolt and the radiator was a little difficult.One hitch in my application is that the water pump pulley is large enough that it partially blocks one of the bolts holding the alternator. It is still possible to get out but you have be careful not to wreck the threads. Additionally, you have to remove it with a wrench as opposed to a socket wrench so it takes longer.To add, this will affect your alternator output. Example:The stock crank pulley to alternator pulley ratio was about 3:1. The alternator pulley was 58 mm with a crank pulley diameter of about 6.9 in. So, when idling (600 rpm) the alternator was at about 1815.15 RPM. Referencing my alternator dyno sheet I could see output at 94 amps @ 1800 RPM. After installing the underdrive kit, your crank pulley is now 5.25 in and the alternator pulley does not change. Now your ratio is at 2.3:1. At 600 rpm your alternator is now at 1381.58. Looking back at the dyno sheet, we're only able to support about 30 amps of load with the alternator now. Notice your lights dimming when you're at a stop light? I did. These output numbers are for my aftermarket 200 amp alternator too. Not the stock 130 for my vehicle.Now if you don't have many accessories running then you should be fine. You may notice it here and there at low RPM's but not significantly and you'll never notice it at higher RPM's. As long as the alternator can keep the output voltage in the upper 13's low 14's you're good. However, I have a lot of accessories and was planning to upgrade to electric fans. Long story short, I got an overdrive pulley for the alternator to get that 3:1 ratio along with a 200 amp alternator to accommodate the higher loads. Sure, it negates some of the effects of the underdrive pulleys but, I needed the higher output.Overall, the kit is very nice. It does what it advertises and is made from great quality materials. Since I installed my kit I've contacted both BBK Performance and Powermaster to get the aforementioned numbers. Both companies were very polite and helped to the best of their ability. Do the math before you buy and you won;t be disappointed.

This application went on my 2001 Ford F150 with the 5.4 V8 2v. Very pleased overall it will require some time and effort to install but overall very satisfied with it. Noticeable gains looks great under the hood. Would definitely recommend.!

First of all the bolt is only used to properly seat the pully on the crankshaft . You use the original washer and bolt to torque it down to 60 ft pounds then back it off one full revolution and finally torqued to 24 ft Pounds. In all its a good product I am satisfied with the pulleys they sell one from steeds wich does not have to be bolted to the original crankshaft pulley wich is the only reason I gave this one 4 stars . Thank you I hope this was helpful

Works great easy install. Iv has this set up on my truck for a couple years and no problems

I'd have given the 5th star, but the alternator pulley was the same size as the one already on the truck. Wjy did I spend the time to swap them out if they were the same size? I did it anyway, since the lighter aluminum looked much better. Easy install overall. Definitely need a puller, an impact, and the directions don't tell you that you need to clearance a piece of the engine block in order for the water pump pulley to fit. That's right, you will need to remove some metal from the engine block. Could have used that information up front. Good mod, however. Definitely a noticeable improvement in power on my old 5.4. Got back what I lost when I want to 35" tires. Worth the time and effort.

Do not waste your money. Bought these in 12/16 when in a year the crank pulley had failed and stripped out. Junk set up.

One of the pulleys did not fit my 2002 ford expedition 4x4 5.4 if you can't use all of the pulleys it defeats the purpose

they work