The Mercedes 126 is a very robust design that can be expected. Nowadays it was one of the best units that used Porsche in the legendary 928. Like all other machines, we should not let the longevity fame prevent common services.
As a general rule, the gear fluid must be changed by 30,000 miles. Contrary to modern cars, where there is a tendency to keep service access ports away, these Mercedes drives allow us not only to lower the pan but also the torque transducer. In other words, almost all the liquid fills can be removed without using cracks like power supply.
Since the engine oil needs to be replaced hot, the transmission fluid can best be changed most when it is strictly warm to protect the mechanic from the real risk of slipping. The steps are as follows:
- Drive the front of the car to ramp or ramp.
- Make sure that the torque converter drain plug is accessible. Unless you are very lucky, you should normally turn the engine on with the starter to see the connector through the access hole. All of this can be "walked" with a large, flat head screwdriver. It is possible to remove the cross member between the two front axes ("dogs"). The six fastening screws have a hexagonal screw of 17 mm with a torque of 45 Nm.
- Loosen the inlet drain plug with a 5 mm connector and lower it into the pan into a suitable container. If possible, collect all used liquids in a container and measure it; this will help us fill in the right amount.
- When the pan stops, lower the plug of the torque converter (same size as the pan) and lower the torque converter down. There's more fluid here than in the pan.
- When the two main streams have disappeared, loosen the six screws holding the bowl (13mm head) and carefully remove the pan. Do not pour the remaining liquid. Resist the temptation to wipe the inside out with a shop towel: we do not want any fibers here.
- Remove and replace the power filter retained by Phillips head screws.
- Thoroughly clean the pan with a lint-free cloth and replace the rubber seal, including the correct fit. Refit the pan and tighten the screws gradually and evenly to 10 Nm. (According to the manual, 8Nm, a little better, but please do not go too far: these pans are tilted and are not cheap.)
- Replace both drain plugs with new copper nodules. Factory Specifications. 14Nm or about 10lbs / ft. The 3/8 drive is tight and works fine. If you have removed the cross-member, replace it, taking care of the cross section of the screws.
- (Optional) Open the trans cooling lines on the radiator (17 mm wrench) and lower the small amount of fluid in this area. Replace the lines if their condition is in doubt; they are not expensive. Tighten all connections.
- Using a fine-finened filter, add four quarts of fresh fresh Dexron-Mercon Transmission Fluid (ATF) through the oil dip tube. If you can afford it, use synthetic fluid: it helps to reduce the temperature by reducing internal friction and heat is the number one automatic transmission.
- Start the engine and slowly add another three quarts.
- Pull the car off the ramp, walk through all the gears, pause the gears for a few seconds, and then check the fluid level. You do not be the smallest sign in this section. The transmission fluid is very hot; the reference marks on the dipstick are calibrated for hot liquids. So it's okay to have this signal halfway down or less, while the liquid is cold.
- Fold the car for about 20 minutes (yes, at least) to thoroughly warm up the fluid. The transmission fluid continues to warm up, such as engine oil or coolant, and requires friction of actual driving to reach the temperature. Check the liquid again on a level ground. Be careful not to leave any kind of fiber on the dipstick before placing it in the tube. Any level between the signs is OK, but you do not want to exceed the maximum level. If you need to add liquid, take it in very small steps and check again.
If you use synthetic fluid, shifts may be noticeably stronger. If necessary, modify the modulator valve at the driver side of the gearbox. Turn the small knob counterclockwise until the shift quality is unsuitable. Keep in mind that too much slip is bad for the internal clutches.