Transmission shifting hard

2012 MERCEDES BENZ E350

160,000 MILES • 3.2L • 6 CYL • TURBO • 2WD • AUTOMATIC

DA3OOR

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While driving on the highway (90kmh) if I floor the gas pedal for a few seconds (now around 120kmh) and then lift it off immediately, the next gear comes on so aggressively and I hear a loud bang from the back of the car, it feels almost like someone rear bumped into me. I think it happens only between 5th and 6th gear
If I do the same thing but with slightly pressing the gas pedal nothing would happen and the gear would change nicely.

Feb 23, 2022 at 6:32 PM

JACOBANDNICKOLAS

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110,175 POSTS

Hi,

Since it doesn't do this under normal conditions, it doesn't sound like a transmission issue, but rather a worn flex joint on the driveshaft.

When you are full throttle and then let off, pressure is released and there is a drag on the driveshaft in the opposite direction (engine slowing vehicle). If there is play and you hit the throttle again, you can get a clunk if there is excessive wear.

If you look below, pics 1 and 2 explain how to inspect the parts. Pics 3 and 4 explain how to replace the fitting sleeves on the flex disc. I have a feeling if you inspect them, they are the cause of the issue.

Let me know if this helps or if you have other questions.

Take care,

Joe

See pics below.

Images (Click to enlarge)

Feb 24, 2022 at 7:08 PM