Copyright Meritor, Inc., 2021
MM-96147 / Revised 03-21
Page 70
(16579)
Printed in USA
13 Troubleshooting
Troubleshooting
Special Tools
Electronic Vibration Analyzer (EVA) 2 Diagnostic Tool
The Electronic Vibration Analyzer (EVA) 2 is a diagnostic tool that
helps detect low-frequency vibrations in a drivetrain. Axle ratio,
number of cylinders, vehicle speed and engine rpm are factored
into a calculation that determines vibration frequency, amplitude
and the vehicle’s system suspected of causing the vibration.
Figure 13.1.
Use the EVA 2 diagnostic tool to determine the source of the
vibration. Refer to the manufacturer’s instructions for complete
operating information for using this tool. The EVA 2 is available
from SPX Kent-Moore. Refer to the Service Notes page on the front
inside cover of this manual for ordering information.
4005557a
Fig. 13.1
Troubleshooting
Universal Joints
DANGER
Excessive looseness across the ends of the universal joint
bearing cup assemblies can cause imbalance or vibration in the
driveline assembly. Imbalance or vibration can cause component
wear, which can result in separation of the driveline from the
vehicle. Serious personal injury and damage to components can
result.
Use the following procedure to check for looseness across the ends
of the universal joint bearing cup assemblies and trunnions.
1. Hold the INBOARD yoke or fl ange on the driveline with both
hands.
2. Try to move the yoke or fl ange UP-AND-DOWN and SIDE-TO-
SIDE by applying at least 50 pounds (22.7 kg) of force
to the driveline near the universal joints. Figure 13.2 and
Figure 13.3.
• If movement is greater than 0.006-inch (0.152 mm):
Replace the universal joint.
4001794a
Fig. 13.2
Yoke-Style Driveline
4011839a
Fig. 13.3
Flange-Style Driveline
Greaseable Universal Joints
1. Check that all grease fi ttings are installed. Replace missing or
damaged fi ttings. Tighten them to 6 lb-ft (8 Nm). Figure 13.4.
4001802a
Fig. 13.4
2. Check for loose grease fi ttings. Tighten them to 6 lb-ft (8 Nm).