BNZ PWR

Hey guys need some help here...

I have a 1992 300e with about 120K miles. Whenever the car is cold off of a start the car will not shift out of first gear (or is it second??). When I fineally get the car to shift it gives a nice kick. After getting it to shift up once or twice the car begins shifting up and down normally. However, the car still shifts hard by kicking whenerv it shifts up. One other thing i noticed was that the lower the gears are being shifted, the harder the kick. ( i.e 1st to second is much harder than 3rd to 4th).

I have one other question. The car downshifts prematurly. If i give it a little more gas the car just drops a gear. I have heard that this car starts in second gear and that was what I thought the cause was. But same issue in 3rd gear downshifting to second. I just feel that when im driving and i give it a little gas that it doesnt need to drop a gear. So here my question, is there any way to adjust the downshift? I was told its a possiblity...

Thanks for all your help,

CDP

lol...I would also like to know what is causing this problem as well...since I get it but only when I am flooring it from a start. In any case, are you getting it when you're flooring it too?

mhorn

there is a way to adjust the kickdown switch of your transmission. There is a kit that will allow you to adjust this. However, all these cars shift hard when cold. The computer holds the gears longer before up shifting when cold to help warm the motor up faster. There is also a kickdown switch under the accel. pedal. If you floor the pedal and push in this switch, the car will automaitcally shift down a gear. I've heard that these cars start in 2nd from a stop, however my '91 300E starts in 1st from a stop. To check, put your car in the 1-2 gear selector and observe the rpms and speed before the shift. My car will always start in 1st if I'm going about 5mph or less.

BNZ PWR

Its not the kickdown swith on the accelerator... im aware of that and i dont usually floor it that hard anyway. But what could be the problem from the rough shifts between gears. Like I said, the lower the gear, the harder the shift....Something tells me that that the problem of not shifting out of first is connected to the rough shifts between gears

cap'n jasper

The car will change up later when cold to warm up the catalytic converter and engine faster. This is normal.
You can adjust the timing of the shift when warm by adjusting the bowden cable. (or just select 'E' beside the gear lever)
The hard shift might be caused by a worn propshaft coupling. If not you can adjust the 'harshness' using the vacuum modulator on the side of the gearbox but be careful not to get slipping between changes.

BNZ PWR

Thanks for all you feedback everyone.

Two questions reamain.

1) Where do I find the bowden cable and how is it adjusted?
2) How do I locate the vacuum modulator? Driver side of passenger? Any way to distinguish it?

cap'n jasper

Do you want us to come round and do it for you?
Try using the search button.

mhorn

buy a factory repair manual on CD. There's a guy on this forum that sells them for like $10. They will tell you everything you need to know. If you only get the hard shifts when the car is not warmed up, that is normal don't do anything. The car will keep the tanny in 1st longer so the motor revs up and warms up to operating temp faster. Nothing you can really do about that. If the car shifts rough all the time, then you might have a problem. If, however, right when you put the car in gear after starting up, you hear an audible thump in the back when you shift into Drive, then your flex disc is shot. This is a rubber donut looking thing that connects the prop shafts together and absorbs some of the shock when shifting into gear.

SEA-Benz

Hey, I had the exact problem that you descibe. There is a vucuum hose that needs so be plugged. Something about a valve in the tranny that for the 1st upshift of they day is high to warm up the catalyctic converter. The hose is up near the power break booster, so you may want to bring it to a MB tech if you are not very mechanical so you don't damage your breaking system. I plugged the vacuum hose on mine and it has never done that crazy upshift again! Glad there was nothing wrong with the car and a very easy workaround.

xspencex

I have a slightly different problem with my 280 E 4speed.. when it changes from 3rd to 4th under power it seems to really sluch the change and takes a while to get into gear?....the cars done 106k.. not a single porblem before...should I be worried?

Cheers