4.0
ASP Underdog Pulley
While
this install was done on a SOHC Ranger, the steps should stay true with
an Explorer, Ranger, or Sport Trac with either a OHV or SOHC engine.
A mustang installation has additional steps as the power steering pump
is in the way.
If
you have equipped an electric fan, this will need to be removed
to gain the clearance to remove the crank pulley.
Disconnect
battery, remove plastic cover on throttle body and remove Intake.
Intake
removed
Remove
fan and shroud -
Use
a Ford Fan Removal tool to remove fan. Turn the hex shaft of the fan
counterclockwise while holding the waterpump pulley with the wrench
supplied with the kit. This tool can be borrowed from many parts stores
or purchased for $15-$20.
To
remove fan from engine bay, remove the two bolts (10mm) holding the
shroud. Remove shroud with the fan.
As
it looks with intake, throttle body cover, fan, and shroud removed.
Remove
Center Crank Bolt
Using
a socket sized per the instructions, remove center crank bolt. The preferred
method is with an impact wrench as it is heavily torqued. The radiator
will be in the way with most pistol type impact wrenches. Striking a
large ratchet with a hammer may loosen it.
Remove
Serpentine Belt. Pic shows the ratchet inserted into the tensioner ready
to relieve the pressure.
Remove
pulley using a harmonic balancer removal tool. Different "stud" lengths
will be helpful as the clearance is tight between it and the radiator.
Stock
pulley on the left, underdog pulley on the right.
Remove
plastic collar from original pulley and install it in underdog 4.0 pulley.
I used the puller tool, but a flat tip screwdriver will suffice. Be
careful not to break it. Install this piece on the new pulley.
Prep
the new pulley per directions. RTV Silicone and grease will be needed.
I marked the key slot on the exterior of the pulley with a grease crayon.
This made positioning the pulley onto the crank shaft easier. You can
"bump" the starter to move the keyway into a more visible location.
Set
the pulley onto the shaft so that the keyways are line up. Insert the
enclosed longer pulley bolt and screw it about half way down. Remove this
bolt and install the original crank bolt until tight.
Install
a 2" shorter belt.
Torque
the crank pulley bolt to factory specs.
Set
the fan and shroud into the engine bay together. Install both pieces.
Install
intake, cover, and reinstall battery connection.