126 Speedometer repair - PeachParts Mercedes-Benz Forum

MB Neo · #1 04-24-2009, 10:24 AM

I removed the cluster from my 89 300SE because the speedometer stopped working. History is when I bought the car a year ago it wasn't working. Started at some point and ran well until a week ago. Based on some of the feedback I removed the cluster and right now I am looking at the back of the unit & want to be careful before I proceed. How do I delve further into checking the gears of the speedo?

TX76513 · #2 04-24-2009, 10:27 AM

This is probably the best write up on the speedometer/odometer HERE

TIP: Draw a sketch of your cluster on a piece of paper. As you remove screws place them on your sketch so you know which hole they came from. The screws vary in length and it can get confusing on re-assembly

david s poole · #3 04-24-2009, 10:45 AM

great pce but that is for cable drive,the 126 is electronic and is always about plastic gears that have petrified[chemically changed to a very soft state]speedometer.com will have the gears although you will need a good set of eyes for the identification process.

TX76513 · #4 04-24-2009, 10:50 AM

Your are correct David - should have mentioned that. DG pics gave me enough forsight to know what I was getting into.

MB Neo · #5 04-24-2009, 11:50 AM

Should I still remove & inspect gears?

TX76513 · #6 04-24-2009, 11:54 AM

Yes, sometimes it's just the contact plug is corroded - if you don't find any gear damage PM me pretty sure I have a few electronic modules for a 126 boxed up. Good time to paint needles and replace bulbs and such.

TIP: Make up some numbered tape tags so when you are unplugging idiot lights to remove cluster you know what order they go back.

MB Neo · #7 04-24-2009, 02:55 PM

I removed & inspected. The gears that I did see - I rotated and they were for the odometer which works fine. I didn't see too much else in there. I didn't remove the other 2 screws that appear to release the speedometer from the rest on the workings. What internal issues should I be looking for? All connections seem to be clean and bright.

TX76513 · #8 04-24-2009, 03:18 PM

It could be something easy like loss of power (pulse). These are analog electronic speedo's Does your cruise control work? Follow your cabling to make sure the sending unit didn't pop off the trans. MB Neo what state are you located in?