Copyright Meritor, Inc., 2021
MM-96147 / Revised 03-21
Page 75
(16579)
Printed in USA
13 Troubleshooting
Table L: Yoke or Flange Fracture
Condition Cause
Correction
Yoke broken or cracked
4001864a
Mating yoke lug interference at full
jounce and rebound
Replace the yoke. Check the design for application. Use high angle
yokes.
Excessive torque load for universal
joint and driveline size
Replace with a higher capacity universal joint and driveline.
Bending fatigue due to secondary
couple loads
Reduce the universal joint continuous running angles.
Table M: Universal Joint Center Parts
Condition Cause
Correction
Cross or trunion fracture
Abnormally high loading
Check for abuse of vehicle, stuck or overloading.
Bushing fracture
Excessive load for universal joint
Check for maximum driveline torque in lowest gear. If necessary,
replace with a higher capacity universal joint and driveline.
Excessive angularity
Check the universal joint operating angles. Reduce the angles if
necessary.
Worn or damaged parts
Replace with new parts.
Table N: Yokes — Wing-Style Bushings
Condition Cause
Correction
Loose bolts
Dirt or foreign material, such as
paint, on mounting pad
Check for fretting on the mounting pads or drive tang.
Surfaces must be free of foreign material and the bushings must be
fully seated before bolts are fully tightened.
Broken bolts
Over or under torqued bolts
• If there is no fretting on the
mounting pad or bolt hole and
there is fretting on the drive
tang:
The bolt broke.
• If there is fretting on the
mounting pad or bolt hole:
The
bolt was loose.
Surfaces must be free of foreign material and the bushings must be
fully seated before bolts are fully tightened.
Excessive angularity
Check the universal joint operating angles. Reduce the angles if
necessary.
Table O: Yokes — Round Bushings
Condition Cause
Correction
Extremely hard to remove or
replace bushing
Distorted bushing hole in yoke or
normally close clearances, fretting
corrosion and rust build-up
When you remove a bushing, use a penetrating oil and be careful
not to distort the ears on the yoke when you hammer on the center
cross. Remove grease, rust and dirt from the mounting surfaces
before assembly. Apply NeverSeez to make disassembly easier.
New center parts will not fl ex
when you install them into the
yoke
Yoke ears are distorted, causing the
center parts to bind
Replace the yoke.