going through my fluid replacements on my new-to-me 300e, i did a tranny fluid change w/ filter, gasket etc. i used semi-synth valvoline dex III. there was hardly a change in smoothness and in fact it has been shuddering slightly at moderate acceleration shifting from 3-4. at low and higher acceleration it does not happen. yesterday i tried to get the car moving quickly after putting it in drive and it shuddered a bit. do i have to back off the modulator adjustment to "soften" the shift? will a tube of lubegard help or does that have longer term negative effects? my plan was to run this semi-synth fluid for 10-15k then drain and refill it with MB tranny fluid but now i'm concerned with that annoying little shudder...

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joE
1993 300e-2.8 - gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"
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Are you sure the fluid level is correct? It's sometimes hard to tell what the correct level is when you just pour it in. I've seen a 91 420sel shudder and it turned out to be low on ATF. The fluid barely touched the dipstick. It took almost a whole quart to bring it to proper level and the shudder went away. Hope this helps.

Nolan

yep, i spent a half afternoon getting it just below the max line with a hot engine. also this tranny is 20k miles new and i have not been happy with shift points etc. from when i got the car 1.5k miles ago. i have a feeling it was not adjusted properly when they installed it.

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joE
1993 300e-2.8 - gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"
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Mercedes transmissions use a throttle valve cable and kickdown solenoid to control shift timing in relation engine load. However, working pressure and shift feel are controlled by modulator pressure which is influenced by engine vacuum. Do you have the correct vacuum modulator and has it been adjusted properly for your vehicle application? There is a stamping on the trans case on the passengers side just above the pan rail below the B1 servo cover. After the first ten numbers there will be a 722, a space, and then three numbers right after the 722. Either beginning with a 3, or a 4. This would tell me which modulator is required and what the correct adjustment relating to modulator pressure will be for your particular vehicle. This is where you need to begin before any further diagnosis.

I am pretty sure it is a 722.4 although I haven't verified visually. According to the VMI printout, the tranny was replaced at 33k miles under warranty 2 years ago (NC indicated). I have my suspicions about whether or not it was adjusted correctly as I have never been happy with the way it behaved. The kickdown switch operation for one is a question mark. When I first got it it refused to kickdown at all. I took off the switch and checked it with an ohmeter and found it to be operational. When I replaced it and retested it started kicking down but it never upshifts beyond 4500 rpm so I wonder if that is working at all as that appears to be the wide open throttle upshift point. Aside from that, operation was smooth prior to the tranny service.
The torque shudder started immediately after the service approx 500 miles ago. BTW this is a very subtle shudder that maybe only I feel at certain speeds in the 3-4 upshift but I still want to fix it as this is my daily driver...

__________________
joE
1993 300e-2.8 - gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"
http://banners.wunderground.com/bann...L/Key_West.gif