A/T - 4F20E Whine In Overdrive Between 25 and 45 MPH

Article No.
95-13-6

07/03/95

^ NOISE - "WHINE" - OVERDRIVE GEAR BETWEEN 40-72 KM/H (25-45 MPH) - TRANSAXLE - 4F20E - VEHICLES BUILT FROM 4/13/92 THROUGH 2/1/94

^ TRANSAXLE - 4F20E - OVERDRIVE GEAR "WHINE" BETWEEN 40-72 KM/H (25-45 MPH) - VEHICLES BUILT FROM 4/13/92 THROUGH 2/1/94

LIGHT TRUCK:
1993-94 VILLAGER

ISSUE:
A "whine" noise from the transaxle may be heard on light, tip-in acceleration between 40-72 km/h (25-45 mph) on some vehicles. This may be due to the transaxle front sun gear teeth being displaced during a production process (this process has been revised to reduce the displacement).

ACTION:
Replace the front and rear planetary assembly and the front and rear sun gear. Refer to the following Service Procedure for details.

SERVICE PROCEDURE

REMOVAL

Remove the transaxle assembly following the procedures in the 1993 Villager Service Manual, Page 07-01-40.

1. Remove the torque converter from the transaxle.

2. Mount the transaxle in bench-mounted holding fixture T57L-500-B.

3. Remove the transmission drain plug.





4. Set the manual shift linkage rod to any position but Park (Figure 1).





5. Remove the twenty one (21) transmission oil pan bolts, the transmission oil pan and the oil pan-to-case gasket (Figure 2). Discard the transmission oil pan bolts and oil pan-to-case gasket.

6. Remove and clean both oil pan magnets (Figure 2).

CAUTION:
MARK THE LOCATION OF THE OIL PAN MAGNETS DURING REMOVAL (FIGURE 2). THE OIL PAN MAGNETIC FIELD CREATED BY THE OIL PAN MAGNETS DISTURBS THE OPERATION OF THE SOLENOIDS. PROPER VALVE OPERATION REQUIRES THAT THE OIL PAN MAGNETS BE INSTALLED IN THE SAME LOCATION THEY WERE REMOVED FROM.

7. Be sure that the transaxle and the transmission oil pan mating surfaces are free from all old oil pan-to-case gasket material.





8. Remove valve body bolts a (5 bolts), b (6 bolts), and c (2 bolts) (Figure 3).

NOTE:
IDENTIFY THE VALVE BODY BOLTS FOR INSTALLATION.





9. Remove the spring clip from the valve body wiring harness grommet (Figure 4).





10. Slide the valve body wiring harness grommet and wiring harness through the transaxle case (Figure 5).

11. Remove the main control valve body from the transaxle case.





12. Remove the D-R accumulator return spring from the D-R piston (Figure 6).





13. Apply compressed air to the N-D accumulator piston to remove it from the bore (Figure 7).





14. Remove the three (3) low/reverse clutch apply oil transfer tube bolts (Figure 8).

15. Remove the low/reverse clutch apply oil transfer tube and rear oil transfer tube seal (Figure 8). Inspect the rear oil transfer tube seal on the end of the low/reverse clutch apply oil transfer tube.





16. Remove the twenty one (21) torque converter housing-to-transaxle case bolts (Figure 9).





17. Tap lightly on the torque converter housing with a soft hammer to separate the torque converter housing from the transaxle case (Figure 10).





18. Remove the differential oil port 0-ring from the differential oil port (Figure 11).





19. Remove the differential from the transaxle case (Figure 12).





20. Remove the input shaft 0-ring from the input shaft (Figure 13).

21. Remove the eight (8) oil pump bolts, then lift the oil pump and oil pump baffle plate from the torque converter housing.





22. If the reverse clutch drum thrust washer and the 3-4 clutch drum bearing race are not removed with the oil pump, remove the reverse clutch drum thrust washer and 3-4 clutch drum bearing race from the reverse clutch drum (Figure 14).





23. While holding the band adjusting stop, loosen the band adjusting stop locknut (Figure 15).

24. Remove the band adjusting stop, washer and band adjusting stop locknut.





25. Remove the 2-4 band and band strut from the transaxle case. Secure the 2-4 band with a band retaining clip or mechanic's wire (Figure 16).

CAUTION:
TO PREVENT DAMAGE TO THE 2-4 BAND DURING REMOVAL, DO NOT STRETCH THE 2-4 BAND EXCESSIVELY.





26. Remove the input shaft along with the 3-4 clutch/reverse clutch assembly (Figure 17).





27. Remove the 3-4 clutch hub and the primary sun gear from the transaxle case (Figure 18).





28. Remove the primary sun gear and the primary sun gear upper thrust washer from the 3-4 clutch (Figure 19).

29. Remove the primary sun gear bearing race from the top of the primary sun gear (Figure 19).





30. Remove the primary sun gear lower thrust washer from the front planet (Figure 20).





31. Use a screwdriver to remove the low one-way clutch pressure plate retainer snap ring (Figure 21).

32. To avoid damaging the low one-way clutch (roller), have an assistant hold the low one-way clutch, and turn the transaxle over.

33. Rotate the front planet and remove the low one-way clutch (roller). If the low one-way clutch (roller) does not slide out, gently tap the transaxle case with a plastic hammer until the low one-way clutch (roller) slides out.





34. Turn the transaxle case back over and use a screwdriver to remove the low/reverse clutch piston pressure plate retainer snap ring (Figure 22).





35. Remove the front planet and the low/reverse clutch piston assembly (Figure 23).





36. Remove the low/reverse clutch piston spring retainer from the low/reverse clutch piston (Figure 24).





37. Remove the rear sun gear front thrust bearing and the low/reverse clutch piston assembly from the front planet (Figure 25).





38. Remove the rear planet assembly from the transaxle case (Figure 26).





39. Remove the rear sun gear from the rear planet (Figure 27).





40. Remove the rear sun gear rear thrust bearing and the rear planet thrust bearing from the rear planet (Figure 28).

REVISED PARTS INSTALLATION

Using the procedure in the 1993 Villager Service Manual, beginning with Page 07-01-121, reassemble the transaxle using the revised front and rear planetary, and the revised front and rear sun gear.

NOTE:
TWO (2) END PLAY CHECKS AND THE 2-4 BAND ADJUSTMENT MUST BE PERFORMED AFTER REPLACEMENT OF THE REVISED PARTS.

TOTAL END PLAY ADJUSTMENT





1. Place Gauge Bar T80L-77003-A across the output shaft bearing surface (Figure 29).

2. Using a Depth Micrometer D80P-4201-A, or equivalent, measure from the top of the gauge bar to the mating surface of the oil pump assembly (Figure 29). This reading will be measurement A.

NOTE:
ALWAYS MAKE MEASUREMENTS IN AT LEAST TWO (2) PLACES.

3. Subtract the gauge bar thickness, 17.78 mm (0.700"), from measurement A. This sum will be measurement B.

4. Place the gauge bar across the oil pump mating surface.

CAUTION:
BE SURE THAT THE OIL PUMP GASKET IS INSTALLED ON THE TRANSAXLE CASE OIL PUMP MATING SURFACE PRIOR TO MAKING THE FOLLOWING MEASUREMENTS. READINGS WILL BE INCORRECT IF THE OIL PUMP GASKET IS NOT PRESENT.





5. Measure from the top of the gauge bar to the 3-4 clutch drum and input shaft upper thrust washer. This reading will be measurement C (Figure 30).

6. Subtract the thickness of the gauge bar, 17.78 mm (0.700"), from measurement C to get measurement D. The formula will be C - 17.78 mm (0.700") = D.

7. Subtract measurement B from measurement D to get total end play. The formula will be D - B - Total End Play.





8. If necessary, select a bearing race to bring the total end play within 0.25-0.55 mm (0.0098-0.0217") using the following 3-4 Clutch Drum Bearing Race Size Chart.

REVERSE CLUTCH DRUM END PLAY MEASUREMENT

1. Place Gauge Bar T80L-77003-A across the top of the output shaft rear bearing surface (Figure 29).





2. Use Depth Micrometer D80P-4201-A, or equivalent, to measure from the gauge bar to the oil pump mating surface. This reading will be measurement A (Figure 31).

NOTE:
ALWAYS MAKE MEASUREMENTS IN AT LEAST TWO (2) PLACES.





3. With the gauge bar in the same position, measure to the reverse clutch from the thrust washer mating surface. This reading will be measurement B (Figure 32).

4. Measurement B subtracted from measurement A equals C (A - B = C).

5. Place the gauge bar across the oil pump mating surface and measure to the reverse clutch drum mating surface. This reading will be measurement D.

CAUTION:
BE SURE THAT THE OIL PUMP GASKET IS INSTALLED ON THE TRANSAXLE CASE OIL PUMP MATING SURFACE PRIOR TO MAKING THE FOLLOWING MEASUREMENTS. READINGS WILL BE INCORRECT IF THE OIL PUMP GASKET IS NOT PRESENT.

6. Subtract the thickness of the gauge bar, 17.78 mm (0.700"), from measurement D to get measurement E. The formula will be D - 17.78 mm (0.700") = E.

7. Subtract measurement C from measurement E to get the reverse clutch drum end play. The formula will be E - C = Reverse Clutch Drum End Play.





8. If necessary, select a thrust washer to bring the reverse clutch drum end play within 0.55-0.90mm (0.0217-0.0354") using the following Reverse Clutch Drum End Thrust Washer Size Chart.

2-4 BAND ADJUSTMENT

1. Tighten the anchor pin until the 2-4 band fits uniformly around the reverse clutch drum.

2. Tighten the anchor pin to 4-6 N-m (3-4 lb-ft).

3. Back the anchor pin off 2-1/2 turns. Tighten the anchor pin locknut to 31-42 N.m (23-31 lb-ft).





Parts Block

OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage

OPERATION DESCRIPTION TIME

951306A Replace Front And Rear 5.4 Hrs.
Planetary Assemblies And
Front And Rear Sun Gears

DEALER CODING

CONDITION
BASIC PART NO. CODE

7A399 56

OASIS CODES: 504000, 597997, 702000