PeachParts Mercedes-Benz Forum - View Single Post

can-do · #3 03-20-2002, 12:35 PM

Thanks Guys for the responses,

From what I read on both your posts I assume that your car doesn't downshift either unless pushed to the floor. I am comparing how my turbo drives with vacuum shift to my non-turbo with mechanical shift. At highway speeds of 60mph meeting an extremely steep grade with a length of perhaps a 1/4 mile or more the turbo will slow to a speed of about 50 mph with the same gas pedal height held. Yeah, I'd say it has torque and plenty of power to churn right up the hill no downshift needed, or at least it doesn't. The non-turbo can be mechanically downshifted simply by pushing on the pedal slightly more. Even traveling the hilly coutryside of this state and you are forced to slow to perhaps 25 mph for a turning vehicle, the turbo will stay in 4th gear and slowly accelerate back up to your cruising speed while the mechanical non-turbo will downshift a gear to get your rpms up so acceleration is somewhat quicker. I know all these are observations but I am still curious to know if Mercedes incorporated any sensing device or anything at all that will cause the vacuum operated tranny to downshift? I figured if it was designed to upshift at specific vacuum set points, it should also downshift at relatively the same set points. It would seem strange that the mechancal linkage trannies were designed to do it buy the upgraded vacuum operated ones won't. Something to think about isn't it?
Anyone else out there have any input or can shed some light on this topic please jump in.

Charles