Quote:
Originally Posted by MBeige
Some 81 300CD's were turbocharged, but it was a very limited number.
Find the correct speedometer for your drivetrain application (turbo 3.0L model from '82 to '84 should all be the same). Your current instrumentation, which has not been replaced, is geared for a non turbo which will account for the discrepancy.
But you say your speedo came from an '82 300TD. How can that be if your original post states it has not been replaced?
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I guess I wasn't clear, the last configuration has a diff and cluster from a '82 300TD.
Quote:
Originally Posted by Yak
Something doesn't make sense with the numbers. You shouldn't have a consistent mph difference across a 40 mph speed change - assuming you're in 4th gear the whole time. I would expect the absolute error to change with speed but maintain a consistent percentage difference. Going from a 3.46 to a 3.07, I'd think about 12%. Non-OE size tires will change that.
If you're trying to figure out if there's a speedo that you can use that will get you closer, you'll probably need to figure the different ratios between tire sizes + the tranny + the diff.
This site appears to have the gear ratios and final drives: W123-300D-Getriebe
You're using a TD rear end @ 3.07, but maybe 300D 4 speed gearing @ 3.9, 2.3, 1.41, 1.0? |
The speeds I checked were in different gears (from 2nd to 4th). I too would expect to see the percentage error be the same across all speeds and not the actual speed. I pulled the 4-spd out of a 240D... so I doubt it was a 300D tranny.