Mercedes trannies are loads of fun to shift manually. With fresh fluid they shift RIGHT NOW when you move the lever. Makes driving in the twisties a lot more fun!

One important trick to know is how to get it into first. Normally a 12-valve 300E like yours starts in second. To get it into first, just shift down into "2" when stopped. Then when you take off from the stop and want to upshift, put it into "3" and IMMEDIATELY back to "2"---if you leave it in "3" it will shift from first to third, but if you do the "2-3-2" trick it will shift from first to second. Then, as you accelerate, go up to third by shifting to "3" and to fourth by shifting to "D" like you'd expect.

Once you're rolling you're not going to want to use first, so then you can just shift among second, third, and fourth as much as you want---provided, like someone else said, you don't downshift above 4000 rpm or so and overrev the engine. Other than that, the tranny is made to take it---that's why Mercedes gives you the nice gate that you can shift by feel! Have fun!

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AlexTheSeal: hack mechanic, inadvertent drifting champ, builder of infernal devices, professional epistemologist

'87 300D Turbo, roadtrip mileage champ (for sale!)
'92 Isuzu Trooper, mudder extraordinaire (for sale!)
'82 Honda Silverwing, cockroach of motorcycles
And various boring daily drivers...