In addition to the aforementioned slipping malady, I also wanted to
mention to the group and solicit comments on what seems to me to be an
odd phenomenon of the transmission possibly not shifting into top
gear. It seems like the engine revs high and sounds loud at cruise
speed (65-70 mph); however, it is a non-turbo 5 cylinder diesel. All
engine indications, i.e., temperature, are normal.
I'm guessing that you don't have a tachometer. If you did, then you
could tell what speed the engine is running at highway speeds. That
should be enough for you to be able to tell if it really is in high
gear or not. My 84 300D (turbo model) runs at 3000 rpms at 70. Thats
pretty high, but not as high as it does when it is in 3rd at that
I had a similar problem with mine recently. The throttle position
cable on mine is wore out and got stuck at full throttle once. This
kept it from shifting into high gear, until I unplugged the kick down
solenoid under the pedal. Sometimes when the cable sticks (after full
throttle acceleration) then it has trouble getting into high gear. To
remedy this, I shift to neutral, then back into drive at speed. When
the transmission reengages, it will go into high gear.
You might want to try unplugging the kick down solenoid to see if that
I was thinking about the vacuum modulator instruction I gave you... you have
to turn in clockwise to reduce the vacuum assist... which will make the
shift firmer. Counter clockwise will open up the vacuum for more soft and
also less pressure.
Doug also got a good tip too... about the kickdown.
MB Tranny tech can quickly diagnose the problem but the problem is alot of
them just want $2500+ rather than adjusting for you...
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