Missing third gear on harder acceleration?

[Eminent]

Most of the time when i drive my W108 it switches smooth from second to third to fourth.
But sometimes, when accelerating  harder, it switches directly from second to fourth.
The revs drop down and it takes much longer before i am at the speed i wanna be.
Is this normal on harder acceleration? If not, what can be the reason it "forgets" the third gear?
Thanks for your answers.

[wwheeler]

Eminent,

I have the same problem on my '68 W111. It shifts great normally but does miss 3rd occasionally. It always does it if I start off from a full stop at the bottom of a small hill. It of course starts in second gear and it will then hold the shift out longer than normal and then goes right to fourth. The RPMs then drop too low as you would expect and acceleration suffers.

Going up the hill requires more throttle which matches your situation. With more throttle, there is less vacuum. So maybe an adjustment to the modulator is needed? If so, which way? Looking forward to answer to this!

[Eminent]

Hmm...two cars from '68 and the same "problem"?
Well, i'm curious too. See if other members have an explanation or solution.

[Eminent]

Hmmmm...seems to be a "problem" just for the two of us...

[gimp]

I too have the same problem with my 68 ever since i have owned it.
My solution, If I require to accelerate faster than normal, I would move my shift leaver to 3
and manually shift to 4.

Frank

[Eminent]

Yes. Thats my solution also. So now it's the three of us problem. All with '68 cars  

[Cees Klumper]

Mine has not skipped third gear ever on brisk accelleration (probably also not on normal accelleration).

[ctaylor738]

I worked on a 250SL that had this problem in addition to premature shifts through all gears and no kickdown.

All of the problems were resolved by an adjustment of modulating pressures as described in the BBB.

It is a royal pain.  The first step is to set the pressures by adjusting the length of the rod that connects the three position switch to the modulator.  The second is to drive the car and observe the pressures and adjust them and the shift points with the screw on the modulator.  Drive, raise car, adjust, repeat, repeat.

This has to be done with a pressure gauge and it was a challenge finding fittings to connect the gauge to the test port on the transmission.

The work-around is to move the shifter to 3 and control the shift yourself.