Auto 1966 230sl..Downshift

[Theo113]

I have been aware that rough/loud downshifting to 1st is a characteristic of the 230sl.  Is there anything that can be adjusted or done to lessen this rough downshift?   Thanks for your comments.

[Pawel66]

The primary suspect may be the throttle switch adjustment. But I would check the overall tune of the gear box (3 way solenoid operation, modulator pressure) and replace oil if it was not replaced for a longer time.

[Theo113]

Thank you , Pawel66

[WRe]

Hi,
there is a special section in the Technical Manual about "rough shifting."
You can start with adjusting the throttle switch by increasing the revs from 1200-1300 to 1400-1500rpm. How?

Disconnect both cables at the throttle switch. Connect one terminal of it to ground and connect the test lamp to the other terminal. Connect the test lamp to the positive terminal of the battery. With the handbrake on, let the engine run at idle speed and move the gear selector to one of the driving positions. The test lamp must be on at idle speed. It must turn off when you accelerate more than 1200-1300rpm usually, rough downshifting 1400-1500 rpm. If the test lamp does not turn off when the shut-off speed is reached, the idle gas switch must be set.
Setting the throttle switch:
Slightly loosen the fastening screws (allen key) of the throttle switch an turn it a little bit until the test lamp turns off at the revs mentioned.
Tighten the fastening screws again and repeat the test again.

Are you aware that our cars usually start and stop with the 2nd gear. The 1st gear is used when you shift to "2" only or pushing kick-down during start.
...WRe

[Theo113]

WRe   Thank you for the information and detailed instructions and grafic on how to accomplish this adjustment.  Regarding your statement that "... that our cars usually start and stop with the 2nd gear. The 1st gear is used when you shift to "2" only."  I am not aware of that and am also not sure i full understand what it means, sorry for my ignorance.  Would  you be so kind as to illuminate that statement for me please?

[WRe]

Hi,
our auto transmissions K4A025 are 4-gear transmissions but you use 3 gears only during normal operation, 2nd, 3rd and 4th gear.
From standing start, the transmission starts in 2nd gear unless the shifter is in the "2" position or you push the kick-down switch. Then it starts in 1st gear and shifts into 2nd. Then you must move the shifter to "4" or "D" and it will shift into 3rd and into 4th.
Downshifting works similar and car stops in 2nd gear.
...WRe

[Theo113]

WRe....Thanks for the additional explaination.  I am 15 years into 230sl and still learning even the relatively simple things,  Thanks!