Dodge D150 1990 Service Manual page 740

# — DRIVE SHAFTS AND UNIVERSAL JOINTS 16-1
DRIVE SHAFTS AND UNIVERSAL JOINTS
C O N T E N T S
Page Page
GENERAL INFORMATION . 1 SPECIFICATIONS 27
SERVICE PROCEDURES 10
G E N E R A L INFORMATION
INDEX
Page
Description . . . . . . . . . . 1
Vehicle Configuration . . . . . . . . . . . . . . . . . . . . . . . 3
DESCRIPTION
DRIVE SHAFTS
R a m T r u c k and Ramcharger vehicles use t u b u l a r
steel drive shafts (Figs. 1 and 2) to transfer engine
torque f r o m the transmission t o t h e rear axle (2WD
vehicles) a n d to transfer engine torque from t h e
transfer case to the f r o n t and rear axles ( 4 W D vehi-
cles). U n i v e r s a l j o i n t s are used t o connect each drive
shaft to the transmission (or the transfer case) out-
p u t shaft and to t h e drive p i n i o n gear shaft (axle)
yoke.
A n internally-splined, s l i d i n g type (slip) yoke ( w i t h
a shaft) is located a t t h e f r o n t end o f r e a r drive
shafts (Fig. 1) to compensate for v a r i a t i o n s i n t h e
distance t o the rear axle caused b y rear suspension
spring and axle movement. T h e i n t e r n a l l y splined
slip yoke shaft slides fore and a f t on the e x t e r n a l l y -
splined drive shaft t o compensate for rear axle " u p -
and-down" movement w i t h t h e road surface (i.e., t o
shorten a n d lengthen t h e effective d r i v e shaft
length). A rubber boot protects t h e d r i v e shaft
splines f r o m road splash.
A s l i d i n g type (slip) yoke (Figs. 1 and 2) is also lo-
cated a t the front end o f f r o n t drive shafts (4WD) t o
compensate for variations i n t h e distance between
the transfer case and the f r o n t axle d i f f e r e n t i a l case
caused b y front suspension spring and axle move-
ment. T h e internally-splined slip yoke shaft slides
fore and a f t on the externally-splined d r i v e shaft t o
compensate for distance v a r i a t i o n (i.e., t o shorten
and lengthen the effective drive shaft length) be-
Page
Vibration 3
tween the f r o n t axle differential housing and transfer
case. A rubber boot protects t h e drive shaft splines
from road splash.
Vehicles w i t h a n extended wheelbase are equipped
w i t h a two-piece rear drive shaft. The two-piece drive
shafts have a center support b e a r i n g and a U-joint
coupler between the t w o shaft-halves. The ball-type,
center support bearing i s enclosed i n a rubber-cush-
ioned (insulator) support and bracket t h a t is attached
to the frame crossmember.
U-JOINTS
Two different types o f U-joint couplers are used
w i t h the drive shafts:
• single cardan U-joint (Fig. 3) and
• double cardan U-joint (Fig. 4).
A single cardan type U-joint (Fig. 3) is used for
most drive shaft applications and is comprised of:
• a single spider,
• four sets of spider needle bearings,
• four bearing seals,
• four needle bearing caps, and
• four bearing cap r e t a i n i n g clips.
Strap clamps and screws are used t o attach the U -
j o i n t spider to the drive p i n i o n gear shaft (axle) yoke.
The double cardan type U-joint (Fig. 4), also re-
ferred to as a constant velocity (CV) j o i n t , is com-
prised of:
• two spiders,
• one socket b a l l and "seats",
• one l i n k yoke,
• one socket spring,
• one socket yoke,
• one socket yoke needle bearing,
• two t h r u s t washers,