Auto Trans: Manual Shifting - PeachParts Mercedes-Benz Forum

bustedbenz · #1 04-18-2007, 07:08 PM

Just curious... I've heard two things. One quote that recirculates from time to time is that it was some huge design factor that Mercedes thought of, and they specifically advertised that one could manually shift these automatics if so desired.

The other mental camp here is that they're just normal transmissions... yes you can shift them, but they weren't designed with that in mind, and that could represent rougher service and possibly shorter life on them.

(These are opinions gathered from all the reading I've done on the things... which isn't THAT substantial - not just this forum)

So... were we meant to enjoy shifting them? Or are we just getting away with it?

Ara T. · #2 04-18-2007, 07:10 PM

You can do it with any automatic transmission... it's nothing out of the ordinary. It won't do any extra harm except probably to your shifter bushings.

And of course if you did something stupid like shift into L when you're on the highway.

Usually not needed, but sometimes if im in a parking lot I will keep it in 1st gear so I don't have it constantly shifting on me. In stop and go traffic I'll keep it in "S" so that's one less gear shift it has to pointlessly execute.

bustedbenz · #3 04-18-2007, 07:12 PM

I always check the speedometer dots to make sure that I'm not over a gear's limit... and the only reason I ponder damage is that my dad used to fuss at me for doing that to his Explorer... who knows. Thanks for the input.

winmutt · #4 04-18-2007, 07:18 PM

I do know that you cant "pop the clutch" on most normal autos but you can on these. Seems that is an indicator that they are more likley to be ok?

pawoSD · #5 04-18-2007, 07:21 PM

What do you mean by "pop the clutch"? Please explain.

I know what it means to do it on a manual...but on an auto?

bustedbenz · #6 04-18-2007, 07:28 PM

I'm confused too but could it mean revving it up in neutral and then dropping it into gear just as one would spin out with a stickshift by having it clutched in gear and then suddenly engaging it?

Ara T. · #7 04-18-2007, 07:29 PM

No... no... don't do that...

Not quite the same as popping the clutch.

I hope that's not what he was talking about.

pawoSD · #8 04-18-2007, 09:07 PM

Closest I've come to that is having the engine at high idle (1000rpm or so) and putting it into gear (by accident)...it LUNGED forward.

Didn't hurt anything though....that was a long time ago.

As for the manually shifting thing, I go between D and S all the time, and occasionally to L when I want to have some fun.

It WAS a selling point, as it is mentioned in the 300D ad's from the 80's that MB ran in magazines. "Manually shiftable clutchless transmission" or whatever....it said you can "shift it yourself, or let the transmission do it for you, your choice."

300SD81 · #9 04-18-2007, 09:12 PM

What do you mean by popping the clutch? Is that possible? I magically did a burnout one time while powerbraking, but when I tried to show off to my friends a little... It didn't happen.. embarrassing...

Brian Carlton · #10 04-18-2007, 09:46 PM

A shift is a shift.........doesn't matter if it's done automatically.........or if you do it with the shift lever.

However, if you do it, you are probably keeping it in a lower gear longer and letting it shift at higher rpm's. It's this aspect of the behavior that causes more clutch wear.

The act of using the shift lever is meaningless to the transmission.

Cervan · #11 04-18-2007, 09:59 PM

Quote:

Originally Posted by 300SD81

What do you mean by popping the clutch? Is that possible? I magically did a burnout one time while powerbraking, but when I tried to show off to my friends a little... It didn't happen.. embarrassing...

kinda like i did magic doughnuts in the church parking lot? lol i floored it on a wet day and dumped the clutch trying to get those tires to spin oh i have a 1981 240d 4speed. but the wierd thing is that i could get them to spin in dirt.

bustedbenz · #12 04-18-2007, 11:27 PM

OK, thanks... sorry if I wasted anybody's time, it's just I tend to do mine manually a lot and wanted to be sure i wasn't destroying it, there's enough other stuff that needs work.

300SD81 · #13 04-18-2007, 11:35 PM

Quote:

Originally Posted by Cervan

kinda like i did magic doughnuts in the church parking lot? lol i floored it on a wet day and dumped the clutch trying to get those tires to spin oh i have a 1981 240d 4speed. but the wierd thing is that i could
get them to spin in dirt.

I think it was a combination of wet rear brake pads + dry front pads + slightly damp road that let my rear wheels start spinning while the brake held the fronts... If I could just duplicate it in the school lot.......

pawoSD · #14 04-19-2007, 12:53 AM

Both of ours will break the rear wheel loose if I hit the brake and throttle at the same time, especially the '83. They'll both squeal in reverse too.

#15 04-19-2007, 03:35 AM

I've wondered about shifting my '84 300d in this manner. I've become quite fond of staring slow off the line, pissing off the impatient driver behind me, then leaving them in a cloud of diesel smoke!

Am I the only one? The 2 - 3 manual shift should make this even more fun/effective!

Driving around town I tend to keep the car in S, but have been reluctent to shift the car manually while driving. For this reason I would only use S if I was certain not to drive faster than 40mph. Now I can take all the thinking I did about future driving speed and devote it to deciphering the digital display on the Becker radio.

View Poll Results: Were our automatics designed for shifting? Or can we just get away with it?
Mercedes-Benz designed them to be shifted just for fun.	16	55.17%
You can shift if you like but they weren't intended for it and they'll wear out faster.	7	24.14%
I've never even thought about it, and I could have done without being asked the question. :-D	7	24.14%
Multiple Choice Poll. Voters: 29. You may not vote on this poll