+++ Tranny Question +++
 

The car : 1967 250s, AT 230sl 4 speed

The tranny slips up to 4th then OK.

Shifting manualy do's NOTHING.

I need to know something before I start "fidling" in there.

If the diaphragm was shot (or blocked vacum line), would I be able to shift manualy?

Will change AT filter as soon as I'm done fixing the brakes.

Comments welcomed.

DAN

Properly conditioned modulator pressure is critical to those old trannies.

There is a rubber diaphram that failed regularly in the modulator. There also is a device called a double lifting solenoid on the top of the trans. There are three positions, idle, full throttle and everywhere else. The everywhere else position is the unpowered state; meaning the solenoid is powered to the other two positions. The solenoid moves a linkage that attaches to the modulator and the three positions creats three wildly different ranges of modulator pressure.

You should verify the modulator pressure with a gauge and if much less than spec verify that the linkage is in the right position. There is an access cover under the tunnel rug on the right side. Makes a hole the size of a grapefruit at the top.

Thanks for your promp reply.

From your answer, the modulator and/or double lifting solenoid will affect the manual shifting capability as well... correct?

Should I eliminate valve body malfonction?