- - more on speedometer issues - -

[lurtch]

Hello all - - Sorry to be a nuisance on my speedo issues - - but - -

 I think I may have the answer to why my speedometer is so wildly inaccurate to the low side. However, I need a little more help to resolve this dilemma . I do not suspect the speedometer itself, it runs smoothly and is precise and quiet.

My car is a 230SL that was re-engined with a M130.980 some time long before I bought it. The transmission is correct for the sedan power-train also, that is, it's a GA 280 SE.  The differential ratio is  3.27 which I believe is the standard one. However, the data card for my car indicates a different unit serial number than the one currently installed. There were three optional ratios  as well - - correct?

My question is this:   If a sedan power-train is turning  through a roadster differential, is that where the error factor is?  Did the sedans have a numerically higher ratio? Or numerically lower?

Thanks for any help - -  Larry in CA

[rwmastel]

quote:Originally posted by lurtch

The differential ratio is  3.27 which I believe is the standard one......If a sedan power-train is turning  through a roadster differential, is that where the error factor is?

The 3.27 is not a standard W113 ratio.  That's a sedan rear axle.  Do you have rear disk brakes?  Your 230SL should have rear drum brakes (disk in front).

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[psmith]

Hi Larry,

My BBB shows the rear axle ratio of 3.75:1 for both auto and stick 230's unless you have a 5 speed 4.08:1!  I think I saw that you were going on the SF Bay Area drive on May 7th, I'll bring my books so you can check out any other info you may need.  I'm waiting to get my CD version so I can see the pictures better.

Pete S.

[A Dalton]

Someone dropper a diff. from a 108/280se-4.5 in there .. probably at the same time they did the M130 engine... good combo.