Transmission Unit

A761E AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION UNIT: INSPECTION

1. INSPECT 1ST AND REVERSE BRAKE RETURN SPRING SUB-ASSEMBLY

(a) Using a vernier caliper, measure the free length of the spring together with the spring seat.





Standard free length:

23.74 mm (0.935 in.)

(a) If the free length is shorter than the standard free length, replace the brake piston return spring sub-assembly.

2. INSPECT REAR PLANETARY GEAR ASSEMBLY

(a) Using a feeler gauge, measure the rear planetary gear pinion thrust clearance.





Standard clearance:

0.2 to 0.6 mm (0.008 to 0.024 in.)

(a) If the clearance is not as specified, replace the planetary gear assembly.

(b) Using a caliper gauge, measure the inside diameter of the rear planetary gear bushing.





Standard inside diameter:

20.025 mm (0.7884 in.)

(b) If the inside diameter is not as specified, replace the rear planetary gear assembly.

3. INSPECT PACK CLEARANCE OF 1ST AND REVERSE BRAKE PISTON

(a) Make sure that the 1st and reverse brake piston moves smoothly while applying compressed air intermittently into the transmission case.





(b) Using a vernier caliper, measure the level difference (length A) between the upper surface of the brake apply tube and the hitting surface of the No. 4 brake flange at both ends across the 1st and reverse brake piston diameter, and calculate the average.





NOTICE:
The 1st and reverse brake piston must be securely installed to the end face of the transmission case.

HINT
Length A = 22.05 to 22.91 mm (0.8681 to 0.9020 in.)

(c) Using a vernier caliper, measure the combined thickness (length B) of the brake flanges, the 4 brake plates and the 4 brake discs at both ends across the diameter, and calculate the average.





HINT
Length B = 23.11 to 23.89 mm (0.9098 to 0.9405 in.)

Pack clearance = Length A - Length B - 0.22 mm to 1.8 mm (0.0087 to 0.071 in.)

Standard pack clearance:

0.4 to 0.7 mm (0.016 to 0.028 in.)

(d) If the pack clearance is outside the standard, select and install a brake flange that brings the pack clearance within the standard.

HINT
There are 8 types of flanges that can be used to adjust the pack clearance. Select the one with the most appropriate thickness.

Standard thickness H:





4. INSPECT NO. 4 BRAKE DISC

(a) Replace all discs if one of the following problems is present: 1) a disc, plate or flange is worn or burnt, 2) the lining of a disc is peeled off or discolored, or 3) grooves or printed numbers have even a little bit of damage.





NOTICE:
Before assembling new discs, soak them in ATF for at least 15 minutes.

5. INSPECT INTERMEDIATE SHAFT

(a) Using a dial indicator, measure the intermediate shaft runout.





Maximum runout:

0.03mm (0.0012 in.)

(a) If the runout is greater than the maximum, replace the intermediate shaft.

(b) Using a micrometer, measure the diameter of the intermediate shaft at each point shown in the illustration.





Standard diameter:





(b) If the diameter is not as specified, replace the intermediate shaft.

6. INSPECT REAR PLANETARY RING GEAR FLANGE SUB-ASSEMBLY

(a) Using a caliper gauge, measure the inside diameter of the rear planetary ring gear bush.





Standard inside diameter:

32.19 mm (1.2673 in.)

(a) If the inside diameter is not as specified, replace the rear planetary ring gear flange sub-assembly.

7. INSPECT NO. 3 1-WAY CLUTCH ASSEMBLY

(a) Hold the rear planetary ring gear flange and turn the 1-way clutch.





(b) Check that the 1-way clutch turns freely counterclockwise and locks clockwise.

If there is a problem with the 1-way clutch, replace it.

8. INSPECT CENTER PLANETARY GEAR ASSEMBLY

(a) Using a feeler gauge, measure the center planetary gear pinion thrust clearance.





Standard clearance:

0.12 to 0.68 mm (0.005 to 0.027 in.)

(a) If the clearance is not as specified, replace the center planetary gear assembly.

9. INSPECT NO. 2 BRAKE DISC

(a) Replace all discs if one of the following problems is present: 1) a disc, plate or flange is worn or burnt, 2) the lining of a disc is peeled off or discolored, or 3) grooves or printed numbers have even a little bit of damage.





NOTICE:
Before assembling new discs, soak them in ATF for at least 15 minutes.

10. INSPECT NO. 2 BRAKE PISTON RETURN SPRING SUB-ASSEMBLY

(a) Using a vernier caliper, measure the free length of the spring together with the spring seat.





Standard free length:

22.66 mm (0.8921 in.)

(a) If the free length is not as specified, replace the brake piston return spring sub-assembly.

11. INSPECT PISTON STROKE OF NO. 2 BRAKE PISTON

(a) Inspect the piston stroke of the brake piston.

(1) Make sure that the brake piston moves smoothly while applying compressed air intermittently into the transmission case.





(2) Using SST and a dial indicator, measure the moving distance (distance A) of the clutch disc at both ends across the diameter while blowing air into the oil hole as shown in the illustration, and calculate the average.

SST : 09350-30020

09350-06120





Standard piston stroke:

0.6 to 0.9 mm (0.024 to 0.035 in.)

(3) If the piston stroke is not as specified, select and install a brake flange that brings the piston stroke within the standard.

HINT
There are 8 types of flanges that can be used to adjust the pack clearance. Select one with the most appropriate thickness.

Standard flange thickness:





12. INSPECT BRAKE PISTON RETURN SPRING SUB-ASSEMBLY

(a) Using a vernier caliper, measure the free length of the spring together with the spring seat.





Standard free length:

17.05 mm (0.671 in.)

(a) If the free length is not as specified, replace the brake piston return spring.

13. INSPECT FRONT PLANETARY GEAR ASSEMBLY

(a) Using a feeler gauge, measure the front planetary pinion gear thrust clearance.





Standard clearance:

0.20 to 0.60 mm (0.008 to 0.024 in.)

(a) If the clearance is not as specified, replace the front planetary gear assembly.

(b) Using a cylinder gauge, measure the inside diameter of the front planetary gear bushing.





Standard inside diameter:

57.43 mm (2.261 in.)

(b) If the inside diameter is not as specified, replace the front planetary gear.

14. INSPECT 1-WAY CLUTCH ASSEMBLY

(a) Install the 1-way clutch to the 1-way clutch inner race.





(b) Hold the 1-way clutch inner race and turn the 1-way clutch.

(c) Check that the 1-way clutch assembly turns freely counterclockwise and locks clockwise.

If there is a problem with the 1-way clutch, replace it.

(d) Remove the 1-way clutch assembly from the 1-way clutch inner race.

15. INSPECT PISTON STROKE OF NO. 1 BRAKE PISTON

(a) Inspect the piston stroke of the brake piston.

(1) Make sure the brake piston moves smoothly while applying compressed air intermittently into the transmission case.





(2) Using a vernier caliper, measure the level difference (length A) between the upper surface of the brake piston and the hitting surface of the brake flange at both ends across the brake piston diameter.





(3) Using a vernier caliper, measure the thickness (length B) of the brake flange, the 3 brake plates and the 3 brake discs altogether at both ends across the diameter, and calculate the average.

HINT
Length A = 15.29 to 15.77 mm (0.6020 to 0.6209 in.)

Length B = 14.72 to 15.12 mm (0.5795 to 0.5953 in.)

Piston stroke = Length A - Length B

Standard piston stroke:

0.42 to 0.72 mm (0.017 to 0.028 in.)

(3) If the piston stroke is not as specified, parts may have been assembled incorrectly, so check and reassemble them again.

If the piston stroke is still outside the specification range, select another flange that brings the piston stroke within the specification.

HINT
There are 4 different thicknesses for the flange that brings the piston stroke within the specification.

Standard flange thickness:





16. INSPECT NO. 1 BRAKE DISC

(a) Replace all discs if one of the following problems is present: 1) a disc, plate or flange is worn or burnt, 2) the lining of a disc is peeled off or discolored, or 3) grooves or printed numbers have even a little bit of damage.





NOTICE:
Before assembling new discs, soak them in ATF for at least 15 minutes.

17. INSPECT NO. 3 BRAKE PISTON RETURN SPRING SUB-ASSEMBLY

(a) Using a vernier caliper, measure the free length of the spring together with the spring seat.





Standard free length:

15.72 mm (0.619 in.)

(a) If the inside diameter is not as specified, replace the brake piston return spring.

18. INSPECT 2ND BRAKE DISC SET

(a) Replace all discs if one of the following problems is present: 1) a disc, plate or flange is worn or burnt, 2) the lining of a disc is peeled off or discolored, or 3) grooves or printed numbers have even a little bit of damage.





NOTICE:
Before assembling new discs, soak them in ATF for at least 15 minutes.

19. INSPECT NO. 2 1-WAY CLUTCH ASSEMBLY

(a) Hold the reverse clutch hub and turn the 1-way clutch.





(b) Check that the 1-way clutch turns freely clockwise and locks counterclockwise.

If there is a problem with the 1-way clutch, replace it.

20. INSPECT INDIVIDUAL PISTON OPERATION

(a) Check the operating sound while applying compressed air into the oil holes indicated in the illustration.





HINT
When inspecting the O/D direct clutch, check if with the C3 accumulator piston hole closed.

If there is no sound, disassemble and check each parts installation condition.

(1) No. 2 clutch (C2)

(2) No. 4 clutch (C4)

(3) No. 3 clutch (C3)

(4) No. 1 clutch (C1)

(5) No. 3 brake (B3)

(6) No. 1 brake (B1)

(7) No. 2 brake (B2)

(8) No. 4 brake (B4)