On a 1985 300d how do I find the ration on the differential?..The differential is out and on the bench..
thanks for your help in advance
Hybridcruiser

Well, it should be 2.88 to 1. If you want to check, try turning it by hand and counting the axle rotations.

I know its a bad question , but has anyone ever come up with a cheap, easy way to change the diff ratios to get lower RPM's at a given highway cruising speed? This car seems like it would like to shift up one more time, even though it is already in 4th gear.
By contrast, our 1984 300TurboDiesel is turning much lower revs at same road speed, it seems more relaxed and long legged. (not exactly automotive engineering terms ..sorry.)
Another interesting observation.: Even though the 300D is purposely set up to start out from a stop in 2nd gear it is actually faster off the line in normal everyday starts than our 84 300TurboDiesel
Would just like to get lower rpms and hopefully better fuel mileage at cruise. Am getting 24 to 26 MPG on 76 300D. Is this normal?

Yes, swap the differential with one that has a taller ratio.

But you did take over some one else thread. Should start a new thread for your questions.

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Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!

or count the teeth on the gears and divide.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.