hemmje

First off all sorry my english..

i have a 05 w211 3.2 cdi. 5 gear auto

I have a problem with very hard downshift ehen i do a kickdown but only in the low gears 2 to 1 and sometimes from 3-1 or 2? .. if i press the pedal down to kickdown the shift i VERY hard and makes a "bang" in the gear ( i think) ?. in the high gears 3-4-5 there is NO problem when i do a kickdown .

any there maybe know a solution on this problem? or what it can be?

Thanks

F1Fan

What is your maintenance situation for your transmission? This is the 722.6 correct? Have you done fluid changes recently? Also, what about the transmission mount, has that been inspected and/or replaced? I would start with those two and then see if the problem remains. You can do the fluid change and replace the transmission mount very easily yourself.

AUTOdidact

You may also check the driveshaft's middle bearing and the two rubber flexplates.

Torque that reaches these parts is much higher at lower gears.

cetialpha5

I would also check the pilot bushing/transmission connector, sometimes those get soaked in transmission fluid.

https://www.fcpeuro.com/products/mer...tor-2035400053

hemmje

Yes its the 722.6 transmission, and i dont know the history of the fluid change, other than it is on my to do list.

tjts1

Your lockup torque converter isn't operating properly. The easy way to test this is to shut off the lockup function with an MB scan tool and take it for a test drive. If the hardsh shift goes away you found the problem.
The solution is to replace the TCC solenoid and install a new torque converter damper kit like Sonnax 68942-23k. Since you'll be dropping the valve body this is also a good time to replace the conductor plate as preventative maintainance.

AUTOdidact

Not necessarily - afterwards you have a less stiff connection between engine and driveshaft, so the shifts will seem softer anyway, NO MATTER what the problem is.

Further kickdown at higher gears isn't harsh and doesn't produce this weird sound so trans and TC should be ok in my opinion...

tjts1

That's because there's less torque multiplication in higher gears so you don't feel the harshness.