When replacing a hanger bearing, make sure you look for and do not lose track of the
shim pack that is usually located between the bearing mount and cross member. The
shims set the driveshaft angles, and omitting them will result in a driveshaft vibration.
4.4.0 U-Joint Replacement
Replacing U-Joints is a routine shop task and usually requires no special tools.
However, an arbor press or U-joint puller can make the procedure easier and reduce
the risk of damaging the yoke. In most truck applications, you do not have to raise the
vehicle to perform a U-joint replacement. You should begin by removing the grease
fittings because these are easily sheared during the removal process.
CAUTION
When removing a driveshaft with half-round or flange type yokes, support the weight of
the driveshaft with a sling before separating the U-joints.
Before removing a driveshaft, mark the slip yoke assembly and tube shaft with a paint
stick to ensure the correct phasing alignment on reassembly. If the shaft assembly is to
be cleaned before reassembly, use a steel scribe to indent alignment marks (
Figure 8-
52
).
4.4.1 ving U-Joints
The key here is to use the least
amount of force possible.
Although U-joints are relatively
inexpensive and commonly
replaced, the driveshaft, yokes,
and slip spline assembly are
expensive and designed to last
the life of the vehicle.
4.4.1.1 Bearing Plate U-joints
The removal procedure is as
follows:
1. If the U-joint is connected
to full round yokes with
bearing cups, use a
hammer and a chisel to
bend back the lock tabs
away from the bolt.
2. Then remove the four bolts
on the two end caps on the
yoke you are separating.
3. There are several ways to
Figure 8-52 - Scribe mark the driveshaft,
rear yoke, and universal joints before
disassembly.
remove the bearing assemblies from the end yoke bores. A hydraulic jack can be
used to apply a pressure under the driveshaft, raising the bearing cup up out of
the yoke bore. If you use this separation method, you use the weight of the truck,
so you can expect it to give suddenly. Gently tap on the outside of the yoke with
a light hammer if the bearing cup does not loosen when initial pressure is
applied. After the bearing cup has been exposed above the bore, it can usually
NAVEDTRA 14050A
8-57