I have a 1988 SAAB 900 turbo in which the speedometer has gone haywire - as soon as the car starts rolling it jumps to 105-115 mph and stays in that range. I have already changed out the cable and that wasn't the problem. I have the speedo out and a twirl of the mechanism sends it right to 105 mark, so I deduce that something internal is kaput.

Were the speedometers on all 900 models (non-turbo, turbo, S, etc.) all the same for a given model year/series? Or were the transmissions geared differently and thus the speedometers calibrated differently, and hence the different "W" codes?

I have found used speedos, but with different "W" codes on the back. Mine is a W=1.050, I have a bid on a W=1.008.

Any body have a good experience with a speedometer repair shop they would like to share?

 

IIRC the W=1.xxx is a ratio code/rating that it is good to match. If not you might be off a few MPH.

This comes from a vague memory of shopping for a replacement for my now dead '81 900. Although I cannot find anything useful on teh g00gle tonight.

 

I installed the speedometer last night. Tonight I'll take it for a spin with a GPS and see how the speedometer matches the GPS MPH. Stay tuned.