Shift issue

[KienastW111]

Hello! I have 1969 280se column mount automatic and as I was driving yesterday it simultaneously lost the ability to upshift and the speedometer stopped working. I limped it home about a mile in low gear. The transmission fluid looks ok both level and color. Any advice would be much appreciated!

[cth350]

Park, reverse & neutral still work as expected? -CTH

[Sugar Bear]

Check the kickdown switch above the accelerator for being mechanically stuck/jammed. If not check it with an ohm meter for opening/closing.

Open the RF door, with the key on engine off, can you hear the kickdown solenoid operate when flooring/releasing the accelerator?

Good luck!!!

[Sugar Bear]

Speedo not working...just re-read your post.
May not be kickdown unless coincidence not too likely.

[Frank Reiner]

Originally Posted by KienastW111

Hello! I have 1969 280se column mount automatic and as I was driving yesterday it simultaneously lost the ability to upshift and the speedometer stopped working. I limped it home about a mile in low gear. The transmission fluid looks ok both level and color. Any advice would be much appreciated!

The nut that secures the three-legged output yoke to the output shaft of the transmission has come loose.
Both the governor and the speedo drive gear are clamped by that nut; when the nut becomes loose the output shaft rotates within the governor and speedo gear without driving them.

[801mbz]

I agree with Frank

[KienastW111]

Thanks everyone for such quick reply’s, this forum is awesome! Frank I’ll get underneath the car and check that nut. Sure makes sense

[Sugar Bear]

Makes sense for sure. What years/models does this apply to...daily driver is a '91.

Thanks in advance

[Benz Dr.]

Originally Posted by Frank Reiner

The nut that secures the three-legged output yoke to the output shaft of the transmission has come loose.
Both the governor and the speedo drive gear are clamped by that nut; when the nut becomes loose the output shaft rotates within the governor and speedo gear without driving them.

Interesting. A standard will do the same basic things but still move the car of course, only the speedo will register at a much lower speed than what you're actually driving. Hitting the brakes often makes the speedo jump to a speed much higher than what you're driving then it will quickly fall back to nothing.

[aluminum]

Originally Posted by Benz Dr.

Interesting. A standard will do the same basic things but still move the car of course, only the speedo will register at a much lower speed than what you're actually driving. Hitting the brakes often makes the speedo jump to a speed much higher than what you're driving then it will quickly fall back to nothing.

very Interesting

I assume by Standard you mean a stick shift

I have a 1967 250S Stick Shift on column and the Speedo most often only works when you let off the gas or decelerate .
I tried lubing the Speedo cable , no change
I removed the Speedo and see nothing wrong with it . I applied a tiny amount of Lube to the Gears . I checked this twice and it looks perfect ?

I replaced the Cable Housing and Cable no change .


The speedo works only when you let off the gas . As well sometimes it make a squealing noise that stops when you hit the gas again . As well the speedo stops ?


does that sound like the same thing ? a loose retainer Nut on the Yoke ?

As well the speeds when the Speedo is working or trying to work is at all different speeds depending it seems on if your giving a bit of Gas seems it works best with foot off the Gas ?