Transmission Unit

A750E AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION UNIT: INSPECTION

INSPECTION

1. INSPECT AUTOMATIC TRANSMISSION OIL PAN SUB-ASSEMBLY

(a) Remove the magnets, and use them to collect steel particles.
(b) Carefully lock at the foreign matter and particles in the pan and on the magnets to anticipate the type of wear you will find in the transmission.
- Steel (magnetic): bearing, gear and clutch plate wear
- Brass (non-magnetic): bushing wear

2. INSPECT NO. 2 1-WAY CLUTCH ASSEMBLY

(a) Hold the Reverse clutch hub and turn the No. 2 1-way clutch assembly.
(b) The No. 2 1-way clutch assembly turns freely clockwise and locks when turned counterclockwise.
3. INSPECT NO. 3 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.

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

4. 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.)
5. INSPECT FRONT PLANETARY GEAR ASSEMBLY

(a) Using a feeler gauge, measure the front planetary pinion gear thrust clearance.
Standard clearance:
0.2 to 0.60 mm (0.008 to 0.024 in.)
Maximum clearance
0.65 mm (0.026 in.)
If the clearance is greater than the maximum, replace the front planetary gear assembly.

(b) Using a cylinder gauge, measure the inside diameter of the front planetary gear bushing.
Maximum inside diameter:
57.48 mm (2.263 in.)
If the inside diameter is greater than the maximum, replace the front planetary gear.

6. INSPECT 1-WAY CLUTCH ASSEMBLY

(a) Install the 1-way clutch assembly to the 1-way clutch inner race.
(b) Hold the 1-way clutch inner race and turn the 1-way clutch assembly.
(c) Check that the 1-way clutch assembly turns freely counterclockwise and locks when turned clockwise.
(d) Remove the 1-way clutch assembly from the 1-way clutch inner race.
7. INSPECT NO. 1 BRAKE DISC

(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.)
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.

NOTE: 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 calipers, measure the free length of the spring together with the spring seat.
Standard free length:
17.45 mm (0.687 in.)
11. 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.)
Maximum clearance
0.73 mm (0.029 in.)
If the clearance is greater than the maximum, replace the center planetary gear assembly.

12. INSPECT NO. 3 1-WAY CLUTCH ASSEMBLY

(a) Hold the rear planetary ring gear flange sub-assembly turn the 1-way clutch assembly.
(b) Check that the 1-way clutch assembly turns freely counterclockwise and locks when turned clockwise.
13. INSPECT REAR PLANETARY RING GEAR FLANGE SUB-ASSEMBLY

(a) Using a dial indicator, measure the inside diameter of the rear planetary ring gear bushing.
Maximum inside diameter:
32.175 mm (1.267 in.)
If the inside diameter is greater than the maximum, replace the rear planetary ring gear.

14. INSPECT INTERMEDIATE SHAFT

(a) Using a dial indicator, check the intermediate shaft runout.
Maximum runout:
0.08 mm (0.003 in.)

NOTE: If the bend exceeds the specification, replace the intermediate shaft with anew one.

(b) Using a micrometer, check the outer diameter of the intermediate shaft positions shown in the diagram.
Standard diameter:
A
25.962 to 25.975 mm (1.022 to 1.023 in.)
B
25.962 to 25.975 mm (1.022 to 1.023 in.)
C
32.062 to 32.075 mm (1.262 to 1.263 in.)
D
32.062 to 32.075 mm (1.262 to 1.263 in.)
Minimum diameter:
A
25.912 mm (1.020 in.)
B
25.912 mm (1.020in.)
C
32.012 mm (1.260 in.)
D
32.012 mm (1.260 in.)

NOTE: If the outer diameter is outside the standard, replace the intermediate shaft with the new one.

15. INSPECT NO. 4 BRAKE DISC

(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.)
Maximum clearance
0.65 mm (0.026 in.)
If the clearance is greater than the maximum, replace the planetary gear assembly.

(b) Using a dial indicator, measure the inside diameter of the rear planetary gear bushing.
Maximum inside diameter:
20.075 mm (0.790 in.)
If the inside diameter is greater than the maximum, replace the rear planetary gear assembly.

17. 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.)
18. INSPECT PACK CLEARANCE OF FIRST AND REVERSE BRAKE

(a) Make sure the 1st and reverse brake pistons move smoothly when applying and releasing the compressed air into the transmission case.
19. INSPECT NO. 1 PISTON STROKE OF BRAKE PISTON

(a) Make sure the No. 1 brake piston moves smoothly when applying and releasing the compressed air into the transmission case.

(b) Using a feeler gauge, measure the B3 bearing pack clearance between the snap ring and flange.
Piston stroke:
0.42 to 0.72 mm (0.0165 to 0.0283 in.)
If the piston stroke is outside the specification, parts may have been assembled incorrectly.
Perform the reassembly again.
If the piston stroke is still outside the specification, select another flange.

HINT: There are 4 different thicknesses for the flange.

20. INSPECT INDIVIDUAL PISTON OPERATION INSPECTION

(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 with the C3 accumulator piston holes indicated in the illustration.

If there is no sound, disassembly and check the installation condition of the parts.
- No. 2 clutch (C2)
- No. 3 clutch (C3)
- No. 1 clutch (C1)
- No. 3 brake (B1)
- No. 1 brake (B1)
- No. 2 brake (B2)
- No. 4 brake (B4)