Correct Differential? Need help please!
 

Does someone have access to information what the gear ratio of the differential for the 1984 300 Turbodiesel, Vin # WDB AB33AIEA056453 should be?

A second hand diff-assembly installed by a dealer, who claims that all units are the same. They apparently checked with Mercedes and were told that the unit is the same as for my 1985 300 SD Turbodiesel and information on the number of gear teeth of the pinion and the gear wheel are not given.

I have only the Manual for the 1985 SD, which lists in group index 35.1-550/30 F3 the following:

Part number Ratio Number of teeth
123 353 01 85 4.08 23
123 353 02 85 3.92 24
123 353 03 85 3.69 26
123 353 04 85 3.58 27
123 353 05 85 3.46 28
126 356 01 85 3.07 31

This information indicates, that at least on the 85 SD model, different gear ratio's were made.

My milage dropped on the 1984 model from about 26mpg to the present 20mpg. The 1985 300 SD with CA pollution control always gets 23mpg!

For the USA 300D, it was 3.07 through 84 and 2.88 in 85. I would imagine it to be the same for California models, although I don't know at what vin number the change occurred. I might be possible that the California models changed a year earlier than USA models. Somebody will have to look it up by vin number to confirm. Hang in there, somebody with that capability is sure to come along soon.

Edit, By the way, the ratio is stamped on the differential case.

Palangi-

Thanks very much for your help! Your information is correct and correlates with information I received from Mercedes customer assistance, using the vin #.
What's interesting is, they don't seem to have the information in the same detail as the manual I have, listing the number of teeth for the ring gears.

I was told that the ratio is 3.07 :1 for the 1984 Turbo diesel and for the 1985 300 SD the gear ratio is 2.88 :1.

My 85 manual does not seem to have the ratio they quoted, but that's not my concern now.