Driveshaft Runout and Balance. General Procedures

Special Service Tools / General Equipment

100-002 (TOOL-4201-C) Dial Indicator Holding Fixture

Inspection

1. 1
   • Perform a visual inspection of the vehicle. Drive the vehicle and verify the condition by duplicating it during the road test.

   • The problem must be directly related to vehicle road speed. It is not dependent on acceleration or deceleration, or it may be reduced by coasting in the NEUTRAL position.
2. 2
   Refer to: Jacking and Lifting – Overview (100-02 Jacking and Lifting, Description and Operation).
3. 3
   • Inspect the propeller shaft for damage, dents or incorrectly installed universal joints. Rotate the propeller shaft slowly by hand and feel for binding or axial play in the universal joint trunnions. Remove the propeller shaft. Inspect the splines of the sliding yoke for wear, dirt, rust or improper lubrication. Clean the propeller shaft or install new universal joints as necessary. Install a new propeller shaft if damaged. After any repair or installation of new components, recheck for vibration at road test speed.
   • If the vibration remains after inspection, measure the driveshaft runout.

   

Check

1. 1
   • Measure and check against the specified maximum value. Install the dial indicator with holding fixture. Rotate the propeller shaft by turning the axle, and measure the runout at the front, center and rear of the propeller shaft. For a multi-piece propeller shaft, measure each section at the front, center and rear.

   1. If the runout exceeds 1 mm (0.040 in) at the front or center, install a new driveshaft.
      Use special service tool: 100-002 (TOOL-4201-C) Dial Indicator Holding Fixture.

   2. If the front and center are within 1 mm (0.040 in) but there is no rear runout, mark the high point of the rear runout and proceed to step 2.

   3. If the runout is within 1 mm (0.040 in) at all points, recheck for vibration at road test speed. If the vibration persists, balance the driveshaft. Refer to the Driveshaft Balancing section in this procedure.

   

2. 2
   • Mark the propeller shaft on the gear flange. Disconnect the propeller shaft and rotate it 180 degrees. Reconnect the propeller shaft. Recheck the runout at the rear of the propeller shaft.

   1. If runout still exceeds the limit, mark the high point and proceed to step 3.

   2. If runout is within specification, check the vibration at test speed. If vibration is still present, balance the propeller shaft. Refer to Propeller Shaft Balancing in this procedure.
3. 3
   • Excessive propeller shaft runout may be caused by the propeller shaft itself or by the gear flange. To locate the source, compare the 2 high points determined previously.

   1. If the index marks are located close together, within 25 mm (1 in), the propeller shaft is eccentric. Install a new propeller shaft.

   2. If the marks are on opposite sides of the propeller shaft, 180 degrees apart, the sliding yoke or gear flange is responsible. Check the runout of the gear flange. If gear flange runout exceeds specification, a bent gear is indicated.

   3. If the gear flange and gear runout are within specification, perform a road test and check for vibration at road test speed. If vibration persists, balance the propeller shaft. Refer to Propeller Shaft Balancing in this procedure.

   

Driveshaft Balancing – Using Mastertech® MTS 4000 Balancer and NVH Analyzer (Vetronix)

1. 1
   Special Service Tool(s): Mastertech® Series MTS 4000 Transmission Balancer and NVH Analyzer (Vetronix) 257-00018. Working under the vehicle, install the accelerometer. The accelerometer can be connected and installed adjacent to the transmission or the driveshaft differential.
2. 2
   • Clean the area of the driveshaft and install reflective tape, then install the photo-tachometer sensor. The sensor should be positioned at approximately a 20-degree angle from perpendicular to the surface of the reflective tape. Make sure the sensor does not move during the balancing procedure.

   1. Reflective tape.

   2. Photo-tachometer sensor.

   

3. 3
   Special Service Tool(s): Mastertech® Series MTS 4000 Transmission Balancer and NVH Analyzer (Vetronix) 257-00018. Run the driveshaft balance test with the unmodified driveshaft.
   Use Special Service Tool: 100-002 (TOOL-4201-C) Holding Fixture with Dial Indicator.

Vehicles with Threaded Yoke Flanges

1. 1
   Mark the threaded holes in the yoke flange numerically, starting with the top hole as 1. Mark the remaining holes 2, 3, 4 (depending on the flange type, 5 and 6 may also be required). Label the direction of rotation.

   

2. 2
   Special Service Tool(s): Mastertech® Series MTS 4000 Transmission Balancer and NVH Analyzer (Vetronix) 257-00018. Run the first test with the 12 mm (0.47 in) test weight set screw in hole No. 1, previously marked on the yoke flange.
3. 3
   Remove the test weight, then install the weight combination as directed by the Mastertech® Series MTS 4000 Transmission Balancer and NVH Analyzer (Vetronix).

Vehicles without Threaded Yoke Flanges

1. 1
   • Special Service Tool(s): Mastertech® Series MTS 4000 Transmission Balancer and NVH Analyzer (Vetronix) 257-00018. Run the second test with a test weight. Using metal tape, secure the test weight to the end of the driveshaft tube. The weight must be located at the end of the driveshaft tube as close as possible to the weld between the tube and the yoke. Mark the position of the test weight on the driveshaft, as shown in the illustration below.

   1. Test weight.

   2. Weld between tube and yoke.

   3. Driveshaft flange.

   • Select the test weight according to the driveshaft size. Larger driveshafts require 10 g (0.353 oz). Smaller driveshafts use 5 g (0.176 oz).

   

2. 2
   • Remove the test weight, then install the recommended weight at the position indicated by the Mastertech® Series MTS 4000 Transmission Balancer and NVH Analyzer (Vetronix). Using metal tape and epoxy, secure the balance weight to the driveshaft, as shown in the illustration below.

   1. Test weight.

   2. Measure in this direction.

   3. Driveshaft diameter.

   4. Direction of rotation.

   5. Balance weight relative to the centerline of the test weight.

   • Results are displayed relative to the location where the test weight was placed.

   

All vehicles

12. Special Service Tool(s): Mastertech® Series MTS 4000 Transmission Balancer and NVH Analyzer (Vetronix) 257-00018. Run the third test to confirm the repair.

Driveshaft Balancing – Clamp Method

1. 1
   Install 1 or 2 hose clamps on the driveshaft near the rear. The position of the clamp head(s) may be determined by trial and error.
2. 2
   Mark the rear of the driveshaft into 4 equal sectors and number the marks 1 to 4. Install the clamp on the driveshaft with the head in position No. 1, as shown in the illustration below. Check for vibration at road speed. Recheck with the clamp at each of the other positions to find the position that shows minimum vibration. If 2 adjacent positions show the same improvement, place the clamp head between them.

   

3. 3
   If the vibration persists, add a second clamp at the same position and repeat the vibration check.

   

4. 4
   If no improvement is observed, position the clamps in opposite directions, at equal distances from the best position determined in Step 14. Separate the clamp heads by approximately 13 mm (1/2 in) and recheck for vibration at road speed.

   

5. 5
   Repeat the process, increasing the separation until the best combination is found or the vibration is reduced to an acceptable level.