Grand Cherokee 2WD V8-5.7L VIN 2 (2005)
Wiper Arm: Description and Operation
Arm - Liftgate Wiper
The rear wiper arm (1) is the rigid member located between the rear wiper motor output shaft that protrudes from the outer liftgate panel near the base of
the liftgate glass opening and the rear wiper blade (2). The wiper arm is constructed of molded black plastic. A hinged pivot end is also molded plastic,
except for a tapered metal sleeve (3) that receives the wiper motor output shaft and a plate where the arm retaining nut is supported. A molded plastic
cap (4) with a snap feature fits in the hole over the wiper arm retaining nut to conceal the nut and mounting hole following wiper arm installation.
The wiper arm hinge, pivot block and tension spring are all concealed on the underside of the wide end of the arm. The matching wiper blade has two
pivot pins that latch into a receptacle concealed within the narrow end of the arm.
The rear wiper arm is designed to mechanically transmit the motion from the rear wiper motor output shaft to the rear wiper blade. The wiper arm must
be properly indexed to the motor output shaft in order to maintain the proper wiper blade travel on the glass.
The tapered hole in the wiper arm pivot end interlocks with the serrations on the outer circumference of the tapered motor output shaft, allowing positive
engagement and finite adjustment of this connection. A hex nut secures the wiper arm pivot end to the threads on the rear wiper motor output shaft and
the plastic cap snaps over this connection for a neat appearance. The spring-loaded wiper arm hinge controls the down-force applied through the tip of
the wiper arm to the wiper blade on the liftgate glass. The hook formation on the tip of the wiper arm provides a cradle for securing and latching the
wiper blade pivot block to the wiper arm.
