Installing the Underdog Underdrive Water Pump Pulley and

Installing the Underdog Underdrive Water Pump Pulley and
Overdrive Alternator Pulley
By George C
Before beginning this project you MUST have the ASP underdrive crank pulley installed
on your vehicle if you want to install the underdrive water pump pulley. The UDWPP is a
larger diameter and will hit your stock crank pulley. There is no requirement to install the
alternator pulley.
This Project will help you install the Underdog underdrive water pump pulley and overdrive
alternator pulley on a Sport Trac.
I am rating this a 3 wrench project. The one tool needed that most people don’t have is the fan
clutch removal too. This can be rented cheaply or bought for under $50.00 dollars.
This will benefit trucks with a lot of electronics because it will overdrive the alternator by
12%. This has been tested in hot climates and so far the test vehicles have not shown any
increase in engine temperature.
TOOLS :
1 – Clutch fan removal tool
2 – Flat screwdriver or 8mm nut driver to remove the intake tube
3 – 3/8” drive ratchet with 10mm socket
4 – 8mm wrench or socket to disconnect the battery
5 – Impact gun with a thin-wall 11/16” socket
6 – 3/8” drive extension
7 – 13mm socket
PARTS :
1 – UDP4WP (Water Pump Pulley)
1 – UDPODALT (Alternator Pulley)
1 – K060865 Belt (when installing both water pump and alternator pulleys)
First disconnect the negative battery cable.
Next remove the air intake tube.
On my truck I have an aftermarket intake. The stock one is a rubber tube.
Now to remove the fan shroud and clutch fan. First locate the fan nut.
Using the tool loosen the nut counter clockwise. (right hand thread)
You will start to see the threads. It will take a lot of turns to remove the fan nut off the water
pump. Be careful not to let the fan hit the radiator, this could cause damage. Once off let it sit
inside the fan shroud.
Now remove the top 2 - 10 mm bolts holding the shroud on.
Then Remove the fan and shroud.
Now locate the belt tensioner and remove the belt.
Note the way the belt is wrapped. There is a decal on the radiator support.
You are now ready to remove the old water pump pulley. Using your fan clutch tool, hold the
water pump pulley while you loosen the 4 - 10mm bolts holding the pulley on, and remove the
pulley.
Make sure the surface of the water pump is free of dirt and debris. Turn the water pump by hand
aligning one of the bolt holes on top. This will make it easier to install the new pulley. Now
install the new pulley. Make sure to tighten the bolts in a cris-cross pattern, making them hand
tight.
Spin the pulley by hand making sure it spins straight and true.
Now you are ready to start the alternator pulley. Start by removing the 2 wire connections on the
alternator. One is under the little grey boot (10mm) and the other is the clip connection just
below it.
Using a 1/2” socket remove the 3 bolts that hold the alternator on. One is on top and two are on
the bottom. Remove the alternator. Using an impact gun and 11/16” thin-wall socket remove the
front lock nut from the alternator. This is done simply by holding the alternator pulley with one
hand and using the impact gun in the other.
Pull off the old pulley and slide the new one on reusing the nut. Using the impact gun, hold the
new pulley with your hand and tighten for a couple of seconds with the impact gun. Spin the
pulley to make sure there are no noises.
It should look like this.
Lay the alternator back in the engine, install the 3 bolts, re-connect the wires. Do not overtighten the 10mm nut as it will snap.
Install the NEW belt using the routing that is on your radiator support. Make sure there is at least
1” space between the body of the tensioner and the belt itself. If you use the correct belt there
should be no problems. If you did not please double check the belt you are using.
Now you are ready to install the fan and shroud. Tighten the fan clutch hand tight. Install the air
intake tube, and connect the battery. Start the truck, check for any noises, and make sure
everything is running correctly.
Here is a comparison of the old and new pulleys. The new alternator pulley being smaller will
overdrive by 12% and the new water pump pulley being bigger will underdrive by 18%.
This Project is designed to help you install the pulleys, and is not a technical report. There may
be errors and every truck may be slightly different. The author is in no way liable if you cause
damage to your truck following these instructions.
I have these pulleys on my truck for a week now without any problems.
ENJOY!!!!!