Assuming your Jeep is a relatively newer vehicle, the answer is that comparing its transmission functioning to that of the transmission in your Mercedes is like comparing a smartphone to a 1970s desk telephone in terms of technology.

The Jeep likely has a sensors connected to electronic controllers that govern how it decides what gear to be in, and how it shifts. The Mercedes only has a mechanical input for shift point, namely a Bowden cable connected to the throttle linkage, which runs into the transmission.

When you have the throttle depressed while accelerating this cable is telling the trans not to shift up. Once you have reached speed your release of pressure on the go pedal, the cable moves and the trans shifts up.

What your car is doing is what it was designed to do, given the technology. It is holding 3rd gear to give you maximum acceleration.

If the adjuster on the Bowden cable breaks, and the cable doesn't move normally, you have the opposite situation -- the trans will shift itself all the way up into 4th at about 35 mph.

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Mac
2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

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