82 500 SL, but the answer is probably not specific to my model. My speedo & odo were reading 50% too fast, so I got a new speedo p/n 107 542 66 01. Still 50% too fast. So the speedos themselves must be OK. What about the sending unit? Where is it and is it replaceable? I have an 82 and I think this was the year they switched over to electronic pickup on the SL, but I am not sure. Thanks in advance to anyone who can add some value here.

Also, should I be posting this in the SL forum or here?

Rich Mayer
82 500 SL