Order of execution
1. Start the engine until the transmission warms up.
2. Raise the front of the vehicle so that the drive wheels can turn freely.
3. Connect the tachometer and position it so that it is clearly visible.
4. Connect special gauge 09452-21500 with adapter 09452-21002 to each pressure test port. To check the back pressure, a manometer with a measuring range of 3,000 kPa must be used.
5. Measure the transmission fluid pressure at various selector lever positions and engine speeds. If the pressure does not meet the required values, check and repair the gearbox elements.
Automatic transmission А4AF3
№ | State | Standard transmission fluid pressure, kPa | ||||
Selector positions | Speed km/h | Speed of rotation of the crankshaft | Selector lever position | 1 | 2 | |
pressure reduction | Kickdown | |||||
1 | N | 0 | H.H. | Neutral. | 430±30 | – |
2 | D | 0 | H.H. | 2nd lane | 430±30 | 138–277 |
3 | D (SW–ON) | 110 | 2500 | 4th lane | 430±30 | 840–900 |
4 | D (SW–OFF) | 75 | 2500 | 3rd lane | 430±30 | 840–900 |
5 | 2 | 50 | 2500 | 2nd lane | 430±30 | 840–900 |
6 | L | 0 | 2500 | 1st lane | 430±30 | – |
7 | R | 35 | 2500 | Z.x. | 420–480 | – |
0 | 1000 |
Automatic transmission А4AF3 (continuation)
Standard transmission fluid pressure, kPa | |||||
3 | 4 | 5 | 6 | 7 | 8 |
Front clutch | final drive clutch pressure | Low gear brakes and Z.H. | Clutch Regulator Pressure | Clutch damper regulator pressure | Rear clutch |
– | – | – | – | – | – |
– | – | – | – | – | – |
– | 650–710 | – | 570–630 | – | 840–900 |
– | 840–900 | – | 660–820 | – | 840–900 |
– | – | – | 490–785 | – | 840–900 |
– | – | 500–630 | – | 530–630 | – |
100–300 | – | – | – | 500–700 | – |
450 | – | – |
Preliminary actions if oil pressure is abnormal (A4AF3)
Symptom | Probable Cause | Actions |
Line pressures are very low (or high). «Pressure in the pipeline» refer to the standard transmission fluid pressures 2, 3, 4, 5, 6, 7 and 8 shown in the table | 1. Oil filter dirty 2. Incorrect pressure adjustment by the control valve 3. Dirty regulator distributor 4. There is valve body clearance 5. Improper pressure generated by the oil pump | 1. Visually inspect the oil filter and replace if necessary. 2. Check the pipeline pressures according to criterion 2 (Kickdown): 3. Check the function of the control valve and, if necessary, replace the valve body 4. Tighten the valve body mounting bolts and set bolt 5. Check the axial clearance of the oil pump gear and, if necessary, replace the oil pump |
Inappropriate pressure reduction | 1. Incorrect pressure in the pipeline 2. Clogged filter (L-shaped type) 3. Incorrect pressure reduction adjustment 4. Incorrect pressure reduction adjustment 5. Stuck pressure reducing valve 6. There is valve body clearance | 1. Check pressure according to criterion 2: 2. Dismantle the valve body, check the condition of the filter and, if necessary, replace it 3. Check the pressure according to criterion 1: 4. Check the function of the control valve and, if necessary, replace the valve body 5. Tighten the valve body mounting bolts and set bolt |
Incorrect kickdown brake pressure | 1. Damaged D-ring, o-ring, bushing, or kickdown servo piston 2. There is valve body clearance 3. Functional failure of the valve body | 1. Remove the kickdown servo piston and check the condition of the o-ring and D-ring. If there are scratches, replace the D-ring or O-ring 2. Tighten the valve body mounting bolts and set bolt 3. Replace the valve body |
Incorrect front clutch pressure | 1. Damaged D-ring, bushing or kickdown servo piston 2. There is valve body clearance 3. Damaged valve body 4. Worn front clutch piston or retainer, damaged D-ring 5. Damaged oil pump gasket or O-ring | 1. Remove the kickdown servo piston and check the condition of the O-ring. If there are scratches, replace the O-ring or D-ring 2. Tighten the valve body mounting bolts and set bolt 3. Replace the valve body 4. Disassemble the transmission and check for wear on the front clutch piston, the inner circumference of the retainer, or damage to the D-ring. If there is wear or damage, replace the corresponding elements |
Improper final drive clutch pressure | 1. Damaged D-ring, o-ring, or pipeline o-ring 2. There is valve body clearance 3. Damaged valve body | 1. Disassemble the final drive clutch and check the condition of the D-ring, piston ring, retainer o-ring, etc. If there are scratches, replace the corresponding elements 2. Tighten the valve body mounting bolts and set bolt set bolt 3. Replace the valve body |
Low pressure low brake and reverse gear | 1. Damaged seal between valve body and gearbox 2. There is valve body clearance 3. Damaged valve body 4. Damaged low and reverse brake o-ring or retainer o-ring | 1. Remove the valve body, check the condition of the seal and, if necessary, replace it 2. Tighten the valve body mounting bolts and set bolt 3. Replace the valve body 4. Disassemble the gearbox, check the condition of the sealing ring and, if necessary, replace it |
Incorrect torque converter pressure | 1. Jamming of the distributor with an electromagnetic drive of the shock absorber clutch control (DCCSV) or damper clutch control valve 2. Plugged or leaking oil cooler and/or lines 3. Damaged input shaft sealing ring 4. Damaged torque converter | 1. Check the operation of the damper clutch system and DCCSV 2. Repair or replace radiator and/or lines 3. Disassemble the gearbox, check the condition of the sealing ring and, if necessary, replace it 4. Replace torque converter |
Inappropriate reverse clutch pressure | 1. Damaged D-ring, o-ring, or reverse clutch o-ring 2. There is valve body clearance 3. Damaged valve body Probably the same cause as the cause of shock shock clutch control pressure failure | 1. Disassemble the final drive clutch and check the condition of the piston D-ring, retainer o-ring, etc. If there are scratches, replace the corresponding elements 2. Tighten the valve body mounting bolts and set bolt 3. Replace the valve body Probably the same troubleshooting as fixing the cause of shock shock clutch control pressure failure |
Incorrect shock absorber clutch pressure |