Note: Automatic transmission malfunctions can occur for the following five main reasons: poor engine operation, improper adjustment, hydraulic system malfunction, mechanical malfunction, computer or electrical wiring malfunction. Troubleshooting should begin with easily remedied causes, checking the fluid level and its condition, adjusting the shift cable and selector position sensor. Then run a road test to see if the problem is gone or not. If the cause of the malfunction has not been eliminated, further troubleshooting is best done at a service station. Check out the paragraph "troubleshooting' at the beginning of this manual.
Preliminary checks
1. Warm up the transmission fluid to operating temperature (take a little trip).
2. Check transmission fluid level (see chapter 1):
- A) If fluid level is low, add fluid to normal level. then locate and repair the fluid leak (see below).
- b) If the fluid level is too high, drain the excess fluid and make sure there is no coolant in it. The presence of coolant in the transmission means a break in the walls of the transmission heat exchanger in the radiator (see chapter 3).
- V) If the fluid foams, sing it off and refill with fresh transmission fluid. Make sure that the fluid level was not excessively high and that there was no coolant in it.
3. Check engine idling.
Note: If the engine is defective, suspend further checks until the engine problem is corrected and then perform all preliminary checks from the beginning.
4. Make sure. that the throttle cable has free movement.
5. Inspect the transmission control actuator (see paragraph 4). Make sure it mixes smoothly and is properly adjusted.
Fluid Leak Diagnosis
6. Most leaks can be detected by simple inspection. To eliminate the malfunction, most often it is enough to replace the seals or gaskets. If fluid leakage is difficult to detect. The following procedure may help you.
7. Determine what fluid is leaking. Make sure. that it is transmission fluid, not engine oil or brake fluid (Transmission fluid is usually dark red in color).
8. Try to pinpoint the location of the leak. Drive a few miles, then park your car over a large piece of cardboard. After 1-2 minutes, spots should remain on the cardboard, which will help to identify the leak.
9. Look around (very carefully) the heated component and everything around it. Use a mirror if necessary. The most likely places for leakage are gaskets at the joints of parts.
10. If the leak still cannot be located, wipe suspect areas with solvent and dry.
11. Drive a few miles with a warm engine and transmission. changing gears, then inspect the suspect component again.
12. After locating the leak, determine the cause before repairing. If you install a new gasket on a warped flange, it won't help. It is necessary to correct the deformation of the flange.
13. Before repairing a leak, make sure the following conditions are met. Otherwise, fluid may leak again at this or another location.
Note: Some of the following conditions cannot be checked without special tools. These problems should be fixed at the service station.
Leaks through gaskets
14. Check the sump periodically. Check that all bolts are tight and in good condition, the gasket is in good condition and the sump is not damaged (dents in the sump can damage the internal components of the transmission).
15. If there is a leak through the sump gasket, it may be caused by overtightening the sump bolts. damage to the joint surfaces, damage to the gasket, or a crack in the gearbox housing. If a seal was used instead of a gasket, it may not be the correct type.
Leakage through seals
16. If there is leakage from the transmission seal, it may be caused by high fluid level, blockage of the ventilation duct, damage to the seal or incorrect installation, damage to the shaft surface or shaft bearing (Excessive bearing play can lead to seal leakage).
17. Verify that the dipstick tube seal is in good condition and secure. Periodically check the area around the speedometer drive or speed sensor. If a leak occurs, check the O-ring for damage.
Leaks through the hull
18. If there is leakage through the housing, the housing must be repaired or replaced.
19. Make sure. that the oil heat exchanger hose fittings are securely tightened and in good condition.
Fluid leaking through the vent or filler neck
20. If this happens, then the fluid level in the transmission is too high (This may be due to the presence of antifreeze in the fluid), there is a crack in the crankcase, the probe is faulty, the ventilation channels are clogged.