Mitch Haley wrote:
I've got one too, from an auto W123. IIRC, all W123 240D have the same
3.69 diff. If the 300D has a 3.46, that's only 7% taller, probably not
enough to notice in driving, but enough to make you want to grab the
speedo/odo out of the donor car. I believe most of the turbos have
3.07, which might make the wife's car a bit sluggish off the line.
(but at least she's got a torque converter to make up for it. I'm
not sure, but it seems like the 1985 300Dt had a high stall torque
converter and a 2.xx diff, you do not want that in a 240d.
Remember that the differential (and transmission) ratio is calculated to
match the peak engine power to achieve maximum highway speed (recall the
discussions about most Mercedes 5 speeds being faster in 4th rather than
5th). If you drop the differential ratio, (say from 3.69 to 3.46) that
will reduce the top speed of the car - probably only by 4-5 mph or so,
but it WILL almost surely drop it. It may alter economy too, but to say
for sure which way fuel consumption will go is not always clear. That
will depend on driving speeds and load.
Mercedes really did a pretty good job of getting the car to run "just
right" with the engine/transmission/differential they used.
Marshall
--
Marshall Booth (who doesn't respond to unsigned questions)
"der Dieseling Doktor" [EMAIL PROTECTED]
'87 300TD 182Kmi, '84 190D 2.2 229Kmi, '85 190D 2.0 161Kmi, '87 190D 2.5
turbo 237kmi
