Just bought an 83 300D, first MB, first diesel. Learned a lot from this forum before buying, thanks to all the archived good advice on this board.

So I think the speedo is around 7-8 mph high (reads 70, highway speed trap radar sign says 63). I believe it, as when I was holding 70 indicated on the Interstate, I was passed like I was standing still. Had similar readings from three different signs.

I was told by a mechanic that the tranny has been replaced, by one that had been factory remanufactured. Could that end of the speedo be the problem?

It runs around 3000 rpm at (as I recall) 75 indicated. Does anybody have a table or other data on revs vs. speed ratios?

Thanks again....

2000rpm is roughly 45mph and 3000rpm is almost exactly 65MPH with my SD transmission in my TD. I've checked with speed traps and with others following me to check. I don't know if the gear ratios are different in the D/TD/CD than the SD, but I'm fairly sure they are the same.

Rhino,

What size tires do it have?

Are both speedo and odo off by the same percentage?

P E H

My '84 300D and my '83 300TD both have a 3.07:1 final drive and appear to run 45mph @ 2000rpm and 65mph @ 3000rpm.

__________________
Never a dull moment at Berry Hill Farm.

PEH-

Tires are the stock/recommended size. Haven't checked to see if the odometer is off too-good idea. Hmmmm, if so, I wonder if that would mean it may not have all the 174,000 indicated miles??

Rhino,

I have a '79 300SD that speedo is off ( fast) by about 6 % but the odo is within 1%. If put on 225/70R14 tires on the rear, the speedo is right on but the odo reads about 6% less than it should.

So one can be off and the other correct.

P E H