Automatic Transaxle - Overhaul [GF4A-EL]: Other Mazda Millenia I рестайлинг

GEAR RATIOS

TRANSAXLE GEAR RATIOS

POWER FLOW

In the powertrain system, the hydraulic pressure transported by the control valve operates the clutch, and brake, and the planetary gear changes the gear ratio according to the driving conditions.

The powertrain system consists of four pairs of clutches, brake, brake band, two pairs of one-way clutches, and ravigneaux type planetary gears.

ELECTRONIC CONTROLS

Note. Transmission malfunctions may be caused by poor engine performance, improper adjustments, fluid condition or failure of hydraulic, mechanical or electronic components. Ensure all concerns have been properly checked prior to transmission overhaul. See appropriate DIAGNOSIS article.

Item & Control

1. Auto Power Control When driving in "D" range, the transaxle automatically switches between POWER and NORMAL modes depending on driving conditions.
2. Shift Control Detects engine load condition and vehicle speed. Shifts to the best gear position according to the programmed automatic shift diagram.
3. Line Pressure Control Generates line pressure matching the engine load condition and driving conditions. Optimizes line pressure for each shift. When the ATF temperature is low, automatically optimizes line pressure for quick clutch engagement.
4. Timing Control Turning the 3-2 timing solenoid valve ON and OFF controls the operation of the 2-4 brake band and the 3-4 clutch.
5. TCC control Controls TCC according to the programmed TCC points.
6. Engine-transaxle Total Control (Torque Reduction Control) Temporarily lowers engine torque during shift (up and down) to improve shift feel.
7. Engine-Transaxle Total Control (N-D/R Select Control) When a driving range is selected from P/N, the fuel injection amount is controlled to prevent fluctuation in engine speed.
8. Slope Mode Control Changes the shift point to prevent frequent shifting up/down when climbing or descending hills.
9. OBD System Detects and/or records failure of input/output part and transaxle condition .

Shift solenoid A, B, C

Shift solenoid A, B, C control the line pressure applied to the 1-2, 2-3, 3-4 shift valves. The shift solenoid are switched ON and OFF by electric signals from the powertrain control module.

3-2 Timing Solenoid Valve

The 3-2 timing solenoid valve controls the line pressure applied to the 3-2 timing valve. The solenoid valve is switched ON and OFF by electric signals from the Powertrain Control Module (PCM).

TCC Control Solenoid Valve

The TCC control solenoid valve controls the line pressure applied to the TCC shift valve. The solenoid valve is switched ON and OFF by electric signals from the powertrain control module.

Pressure Control Solenoid

1. The pressure control solenoid regulates modifier pressure to control line pressure.
2. The duty-cycle pressure control solenoid freely controls the ratio of ON time in one cycle from 0 to 100%. It repeats ON and OFF at a frequency of 31.25 Hz (0.032 second per cycle), and opens and closes the drain port to control modifier pressure at a specified level.
3. Therefore, modifier pressure increases when the duty ratio (ratio of 31.25 Hz ON time) decreases. Conversely, modifier pressure decreases when the duty ratio increases.
4. When the solenoid valve is OFF, hydraulic pressure applied to the valve is retained. The pressure applied to the valve overcomes the spring force and the valve moves to the left.
5. When the solenoid valve is ON, pressure applied to the valve is drained and the valve moves to the right side by spring force. This valve switches the hydraulic pressure lines and controls the operation of the each component.

ON-VEHICLE SERVICE

See appropriate AUTOMATIC TRANSMISSION SERVICING article in TRANSMISSION SERVICING.

PRECAUTION GENERAL NOTES

The oil pan could contain small chips, shavings and other particles which may be helpful in inspecting the condition of the transaxle and diagnosing certain problems. To ensure that all foreign particles stay in the oil pane, ensure the transaxle is never tipped completely over while the oil pan is still installed.

1. Disassemble the transaxle in a clean area (dust proof work space) to prevent entry of dust into the mechanisms.
2. Inspect the individual transaxle components in accordance with the QUICK DIAGNOSIS CHART during disassembly.
3. Use only plastic hammers when applying force to separate the light alloy case joints.
4. Never use rags during disassembly, they may leave particles that can clog fluid passages.
5. Several parts resemble one another, arrange them so that they do not get mixed up.
6. Disassemble the control valve component and thoroughly clean it when the clutch or brake band has burned or when the ATF has degenerated.

AUTOMATIC TRANSAXLE CLEANING

1. Clean the transaxle exterior thoroughly with steam, cleaning solvents or both, before disassembly.
2. Clean the removed parts with cleaning solvent, and dry with compressed air. Clean out all holes and passages with compressed air, and verify that there are no obstructions.

Scheme 241

1. Mount transaxle on Engine Stand (49 0107 680A) and Transaxle Hanger (49 G019 0A0). Remove torque converter and immediately turn it so that the hole faces upward which will help to keep any remaining fluid from spilling. Remove oil pump drive shaft. Remove oil dipstick, oil filler tube and "O" ring. Remove breather hose. Remove manual shaft nut, input/turbine shaft speed sensor, Transaxle Range (TR) switch and bracket. Remove "O" ring from input/turbine shaft. Remove VSS and "O" ring. Disconnect coupler. Remove connector bolt, oil pipe, packing, spring and steel ball.
2. Remove oil pan and gasket. Inspect any material found on oil pan or magnet to determine condition of transaxle. If large amounts of material are found, replace torque converter. Inspect clutch facing material for drive plate and brake band wear. Inspect bearing, gear and driven plate for wear. Inspect aluminum parts for wear. Remove oil strainer and "O" ring.
3. Remove valve body cover and gasket. Disconnect solenoid connectors and TFT sensor connector. Remove control valve body with electrical harness. Remove oil pipe at oil pump. Remove oil pump and gasket. Remove clutch assembly turbine shaft snap ring and remove clutch assembly.
4. Remove small sun gear and one-way clutch No. 1 assembly. (Scheme 241) Secure 2-4 band with wire to prevent stretching and remove 2-4 band. Pull anchor shaft while holding strut and remove strut. Pull piston stem from 2-4 brake band servo. Remove snap ring, band servo and spring.
5. Remove one-way clutch retaining snap ring, one-way clutch No. 2 and carrier hub assembly. Remove friction plate.
6. Remove internal gear snap ring and remove internal gear from output shell. Remove "O" ring located on converter housing side of turbine shaft. Pull out turbine shaft with 3-4 clutch assembly. Separate turbine shaft and 3-4 clutch.
7. Remove bolts from converter housing to transaxle. Tap lightly with a plastic hammer to remove transaxle case. Remove output shell from output gear. Remove manual shaft and manual plate. (Scheme 242) Remove differential assembly. (Scheme 243)
8. Remove 2-3 accumulator, orifice check valve spring and check valve. Remove bolt in idler gear and output gear bearing housing to access roll pin in idler gear. Drive roll pin out with pin punch. (Scheme 243) Remove baffle plate. Remove other bolts in idler gear and output gear housing.
9. Tap housing with plastic hammer lightly to remove. Tap out idler gear shaft from converter housing and remove idler gear with output gear. Remove bearing cover assembly. Remove converter housing from holding fixture. Press bearing race out of torque converter housing using step plate.

Scheme 242

Scheme 243

OIL PUMP

Note. DO NOT place reference marks on oil pump rotors with a punch.

2-4 BRAKE BAND

After 2-4 brake band servo is removed, remove 2-4 brake band. If damaged or worn, replace 2-4 brake band.

Pre-Disassembly Backlash Inspection

Install left and right axle shafts into differential. Support axle shafts on V-blocks. (Scheme 244) Measure backlash of both pinion gears. Backlash should be 0.002-0.0059" (0.05-0.15 mm). Maximum service limit is 0.004" (0.10 mm). Rebuild or replace differential assembly if backlash is not as specified.

Scheme 244

General Notes

1. Select the adjustment shims, referring to bearing preload.
2. If the drive plates or 2-4 brake band are replace with new ones, soak new parts in ATF for at least 2 hours before installation.
3. Before assembly, apply ATF to all seal rings, rotating parts, "O" rings and sliding parts.
4. All "O" rings, seals and gaskets must be replaced with new ones included in the overhaul kit.
5. Use petroleum jelly, not grease when reassembling.
6. When it is necessary to replace a bushing, replace the subassembly that includes that bushing.
7. Assemble the housing within 10 minutes after applying sealant, and allow it to cure for at least 30 minutes after reassembly before filling the transaxle with ATF.

Scheme 245

Scheme 246

Scheme 247

Scheme 248

Scheme 249

1. Align and install bearing cover into converter housing using a press and Oil Seal Installer (49 G019 017) or equivalent. (Scheme 245)
2. Remove bearing outer race and adjustment shims from bearing housing. Mount output gear assembly on converter housing. Reinstall bearing race onto selector. Install selector and bearing race to output gear. Turn selector to eliminate gap between two halves. (Scheme 246) Mount 4 collars (49 FT01 384) between converter housing and bearing housing. (Scheme 247) Mount bearing housing on selector gauge. Tighten bolts to 96-121 INCH Lbs. (10.8-13.7 N.m). (Scheme 248) Turn selector in a direction which widens the gap between "A" and "B" of selector gauge until it will no longer turn. This will seat bearing race. Turn selector in opposite direction (reducing gap) until gap is eliminated.
3. Mount preload adapter to output gear. (Scheme 249) Measure preload with torque wrench or pull scale. Widen gap on selector gauge to obtain a preload of 10-17 INCH Lbs. (1.08-1.96 N.m) using torque wrench or 2.5-4.4 lbf. (11-19 N) using pull scale.
4. Measure clearance between "A" and "B" of selector gauge when specified preload is obtained. Measure clearance around entire circumference and select shim(s) equal to maximum clearance measured. The maximum allowable number of adjustment shims is 7. Shims are available from 0.015" (0.375 mm) to 0.055" (1.40 mm) in increments of 0.002" (0.05 mm).
5. Remove bearing housing and selector gauge. Install required shim(s), press bearing race into bearing housing. Install output gear and idler gear. Install bearing housing. Tighten bearing housing to specified torque. See «TORQUE SPECIFICATIONS»(ref-172033-S07950791182005021800000). After installing bearing cover, verify output gear bearing preload is 10-17 INCH Lbs. (1.08-1.96 N.m) using torque wrench or 2.5-4.4 lbf. (11-19 N) using pull scale.

Scheme 250

Scheme 251

Scheme 252

1. Remove bearing outer race and adjustment shims from transaxle case. Ensure bearing race is installed in converter housing. Remove ring gear, differential cover, roll pin and short pinion shaft. Install differential cover. Mount differential into converter housing. Turn selector to eliminate gap between two halves. Install bearing race into selector. Mount selector gauge and bearing race on differential assembly. (Scheme 250)
2. Mount 6 Spacing Collars (49-FT01-384) on differential assembly. (Scheme 251) Mount transaxle case onto converter housing. Tighten bolts (49-G019-021 and 49-D019-001) to 28-38 ft. lbs. (37-52 N.m).
3. Turn selector halves "A" and "B" in a direction which widens the gap in selector. This will seat bearing race. Turn selector in opposite direction (reducing gap) until preload is eliminated.
4. Mount Preload Adapter (49-T027-001) into differential until in contacts pinion shaft. Measure preload with Preload Measurement Attachment (49-0180-510B) and torque wrench or pull scale. (Scheme 252) Read preload when differential starts to turn. Measure several times and calculate average value. Adjust clearance of selector to obtain preload of 4.3 INCH Lbs. (0.5 N.m) using torque wrench or 1.1 lbf. (5 N) using pull scale.
5. Measure clearance between "A" and "B" of selector gauge when specified preload is obtained. Measure clearance around entire circumference and select shims equal to maximum clearance measured. Add 0.012" (0.30 mm) to measured clearance. Maximum of 3 shims may be used. Shims are available in the following thicknesses: 0.0039" (0.10 mm) 0.0047" (0.12 mm) 0.0055" (0.14 mm) 0.0062" (0.16 mm) 0.0071" (0.18 mm) 0.0079" (0.20 mm) 0.0197" (0.50 mm) 0.0276" (0.07 mm) 0.0394" (1.0 mm)
6. Remove transaxle case and selector. Install the required amount of shims and press bearing race into transaxle case. Install bearing housing. Check differential bearing preload. Preload should be 27-34 INCH Lbs. (3.0-3.9 N.m) using torque wrench or 6.6-8.8 lbf. (30-39 N) using pull scale. If preload is not within specification, repeat measuring and adjusting procedure (as necessary).
7. Remove differential cover. Install short pinion gear, roll pin, differential cover and ring gear. Tighten bolts to specification. See «TORQUE SPECIFICATIONS»(ref-172033-S07950791182005021800000).