722.3 question
 

Why does the transmission in my 300SE ('90) shift so hard on the 1-2 shift? The 1-2 shift in my '80 300D is almost imperceptible in comparison.

1st gear in both cars is very short (3.46 rear end for the '90, and I believe the same for the '80.).

Put another way, is there a reason the 1-2 shift feels different than the 2-3 and 3-4 shifts?

I've heard others on this board express similar comments, but have never seen a technical answer.

It's the one thing I dislike about the car. If it was a '72 chevelle with a shift kit, I would understand, but the snappy (to put it nicely) shift doesn't feel right in an otherwise smooth S class.

Are there any technical updates or anything of that nature? I would love the car to start in 1st gear everytime, but I do not want to swap valve bodies unless this issue could be resolved.

Your car starts in 2nd gear; you must be talking about a 1st to 2nd gear kick down up shift. The B1 band is applied only in 2nd gear, the problem is in the B1 band or a B1 control problem.

The B1 release clearance can have too much travel, too lose. Check the part number on the piston cover, if its 126 277 25 03 then that is the self adjusting B1 piston, which some times loses its adjustment. The cover is on the passenger side of the transmission, by the bell housing. If you have the 3rd design B1 piston, I would start there first.

The B1 band coefficient of friction can be too high; the transmission could have been rebuilt with a relined B1 band, these bands don’t work will in a MB transmission. The transmission can have the wrong fluid or dirty, worn fluid.

Other possibilities are a stuck or cracked 1st to 2nd accumulator piston, in the valve body.

Do you also have a harsh 3rd to 2nd Kick down shift?

Thanks for the reply, c32.

3-2 kickdown is normal.

Fluid looks and smells ok. I changed it w/filter about 15,000 miles ago, and it smelled/looked fine then as well.

I'll take a look at the part you noted.

Thanks again.

Here is another thread that describes something similar, with responses by other professionals.