Automatic gearbox question

[Ollie]

I have never owned a 60's Mercedes with an automatic gearbox.
The 67 250 SE coupe that I recently purchased is my one and only experience.  The reasearch that I did prior to purchase told me that the gearbox shifts harshly and abruptly,  but seems durable.  My car shift into 3d gear only if the revs run at about 3200 on gentle driving, and at 3800 into 4th.
Does this seem correct?  Is there a way to adjust these shiftpoints?
Must admit that I enjoy the standard gearbox in my Pagoda much more,  although the SE is a great highway cruiser once up to speed.

Thanks for your comments once more.....
Ollie

[douglas dees]

Ollie: you probably have the earlier gearbox. My 69 280 SE automatic coupe has a later version. The Pagoda automatic had a rough shift which I think is the same transmission but can be adjusted by the modulater valve that sits at the side of the transmision. This converns how smoothly  the  transmission shifts. You need to take it to a Mercedes mechanic that understands the transmission adjustment.
Doug Dees
 

[wwheeler]

My '68 W111 early auto gear box shifts more firm than an American trans of the era, but it should not be harsh. There are many things that can effect the shift quality to name a few:

- Throttle linkage set up. If the venturi is open by the slightest when the linkage at idle, it will mess up the shift points. See the Linkage tour here on this site.

- The double acting solenoid. Tells trans if at idle (low pressure), driving rpm (medium pressure) or kick down (high pressure). There are two switches; idle switch on the venturi and the kickdown on the firewall and under the pedal which activate the double acting solenoid. The solenoid also has adjusting turnbuckles.

- Finally, you can adjust the vacuum modulator. I suggest you take quite a bit of time to research all of the functions that can effect the trans shift quality before you look at just the modulator.

I know this because the first two items above on my car were totally set wrong and until I straightened them out, the trans would always shift badly. 

[Ollie]

Thanks so much,  this is very helpful.
ollie

[douglas dees]

Your mechanic should have a tool that lines up the linkages on the fuel injection system. The rod goes through the hole on the brackett at the top of the engine. Make sure that all your ball and sockets on the linkages are in good shape so that the adjustment can be done properly. This alignment makes sure your shift points are correctly aligned especially for the kick down. My old Mercedes guy adjusted mine and it made a world of difference.
good luck
Doug

[GGR]

Make sure your ATF level is right. If too low you will get the symptoms you describe.

[Ollie]

Common things occur commonly - funny how easy it is to miss the obvious!
Thanks GGR,  topping up the ATF did the trick.

Cheers
Ollie

[m300cab]

you may also want to change the modulator valve, they get old and cranky, a fresh one may also do the trick