1987 300td transmission / shifting issues w124 - PeachParts Mercedes-Benz Forum

littlerobot · #1 04-01-2014, 11:13 PM

We bought this car used several years ago. It had 119,000 miles on the odometer. One thing that jumped out about driving it early on is that the transmission shifted 'softly' as opposed to the 'hard' gear changes I've read about on this forum with regard to transmission issues. It would shift from 1st gear to 2nd, and then almost immediately into 3rd gear.

Now it mostly doesn't shift from 1st gear at all. It may occasionally jump into second, but usually just stays in 1st. The best way I can describe it is by saying the tranny seems 'confused'.

I'm much more familiar with w123 models than w124, so I'm wondering where to start based on the symptoms. I know in these models there is a wire / cable that deals with shifting, as well as a switch. Another issue could be the vacuum pump. Before I just say the transmission is shot, what is are the things I need to check?

Thanks for any help or advice you may be able to provide!

jbrianfoto · #2 04-02-2014, 03:55 AM

I've been working thru trans issues with one of my w124 cars. The cable you might be referring to is sometimes called the Bowden cable, or kick down cable. It is attached on one end to the throttle linkage, the other end actuated a little lift lever in the trans. When you press hard on the throttle, this causes the trans to downshift into a lower gear.

There are several really good posts here about the vacuum systems which affect the trans shifting. I'm not able to post links to them on my iPad, otherwise I'd help you a little more.

Good luck

Maxbumpo · #3 04-02-2014, 01:41 PM

Could be the kick-down switch (under the accelerator pedal). Try testing that switch to make sure it is not stuck "on".

Have you been changing the fluid and filter on schedule? Every 15k miles if mostly in-town driving, every 30k miles if highway driving.