Max downshift points w123.133 - PeachParts Mercedes-Benz Forum

MBeige · #1 03-01-2006, 11:44 PM

I've been driving my car for more than 2 years now and it's been such a pleasure as always. But when we got the wagon with twice the miles as mine (see sig below) I noticed that the wagon will readily downshift at 40mph with a prod/stab of the pedal. But the sedan will only downshift until 35mph at most. Higher than that and it won't. I've tried to floor the wagon at 45 and most of the time it won't downshift, but with luck I've been able to.

What's curious is the wagon has black ATF and is in need of a good flush and the sedan's has reddish ATF. Now my question is, is something wrong with the sedan? Should it be able to downshift at 40ish? I know it has a lighter load (sedan vs wagon) but even with a full load on the sedan, it won't downshift as much. I've adjusted the bowden cable on both to set them to the "standard" setting (no slack at idle).

Your thoughts?

rg2098 · #2 03-02-2006, 06:51 AM

I've been struggling with the same issues, mine will downshift into 3rd at 35 or less and 2nd at 15 or less. Makes it difficult going around turns and trying to accelerate. I have started to drive it like a stick and manually tell it when to shift. Eventually I will get all these adjustments right.

MB-Owner-in-ind · #3 03-02-2006, 04:41 PM

The adjustment on top of the valve cover tells the tranny when to shift. One way will make it shift later on the upshift and sooner when passing. Otherwise punch it to the floor and trip the downshift switch.

MBeige · #4 03-02-2006, 05:18 PM

Are you saying that adjust it to shift later will also adjust it to downshift when you want to? I'm pertaining to letting the car downshift when I want to (within gear speed limits of course).

MB-Owner-in-ind · #5 03-02-2006, 07:25 PM

Yes, I believe it to work both ways. This bowden cable adjust the pressure to tell the transmission when to shift. The more pressure exerted on the cable the more it thinks it should be in a lower gear. When speeding up it delays the upshift or tells it to down shift if in too high of a gear. This is the only way the tranny knows when to shift except by rpm. The vacuum modulator gives you a soft or hard shift.

MBeige · #6 03-03-2006, 05:06 AM

That still puzzles me because I've adjust both cars to the spec: no tension on the bowden cable but just right for immediate uptake should one step on the pedal. But with this, I still get the results I posted.

MB-Owner-in-ind · #7 03-03-2006, 11:12 PM

I adjusted my cable to shift later. Put some pressure on it and then test it.

MBeige · #8 03-04-2006, 12:05 AM

Does yours still downshift at 40mph? I've already adjusted it slightly to give it a later shift and am satisfied (shifts at ~35mph) but that's roughly the best it could do.