Rough 1-2 Shift








Your rough 1st-2nd shift is not common. Doesn't you car pick-up in 2nd gear already?
How many miles ago was that ATF service: over 5kMi already ? (adaptations)
When the ATF is still cold it is more viscous than at operating temperature. The valve body solenoid have a harder time delivering a smooth gear shift. (pressure difference)
Have you noticed if the low rpm shifts are very predictable or a little bit random rpm than they should? (PCV leak)
Be curious and indulge in car scans to check there are no faults on the ECU-TCU CAN-C bus.
Last edited by CaliBenzDriver; Sep 30, 2022 at 08:59 PM.




Your rough 1st-2nd shift is not common. Doesn't you car pick-up in 2nd gear already?
How many miles ago was that ATF service: over 5kMi already ? (adaptations)
When the ATF is still cold it is more viscous than at operating temperature. The valve body solenoid have a harder time delivering a smooth gear shift. (pressure difference)
Have you noticed if the low rpm shifts are very predictable or a little bit random rpm than they should? (PCV leak)
Be curious and indulge in car scans to check there are no faults on the ECU-TCU CAN-C bus.




It's a bit low mileage to be banging already - My tranny shifts on its good days are seemless like a CVT

You can simply let your car warm up 5mn while cleaning your windshield and checking emails
Last edited by CaliBenzDriver; Oct 1, 2022 at 12:04 AM.




Your rough 1st-2nd shift is not common. Doesn't you car pick-up in 2nd gear already?
How many miles ago was that ATF service: over 5kMi already ? (adaptations)
When the ATF is still cold it is more viscous than at operating temperature. The valve body solenoid have a harder time delivering a smooth gear shift. (pressure difference)
Have you noticed if the low rpm shifts are very predictable or a little bit random rpm than they should? (PCV leak)
Be curious and indulge in car scans to check there are no faults on the ECU-TCU CAN-C bus.

It's a bit low mileage to be banging already - My tranny shifts on its good days are seemless like a CVT

You can simply let your car warm up 5mn while cleaning your windshield and checking emails




You're saying that idling these cold engines to warm-up tranny ATF promotes bore scoring.
It could really well be that idle is bad!
We know the 2-stage oil pressure is lowered to a minimum and pistons are only get oil sprayed above 3500Rpm.
I am not surprised that poor lubrication can kill these engines, not sure if low emission mixtures washing down cylinder walls are part of this.
Where do you say we should look?
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The dirt of 87K miles and 9 years could have provided good clutch traction when oil cold as extra FRICTION MATERIAL.
Now the oil is new, so clean, the clutch slips a bit and that jerky 1 to 2nd gear is what you feel.
Give it time for clutch to equalize, perhaps it will improve.
Honestly, pass 5 years and 40K miles if for my kind of traffic jam and hot ambient temp = BAD
My 1st tranny oil change was 10,000KM but at 4 years old, 2014 car, 2018 tranny oil change when I bought it. MB Indonesia told me its okey for 6 years and like 75,000KM ...now way.
The tranny response was so improved after 1st oil change.
Also : I hope you do not mistaken immediate reponse as JERKY/ROUGH.
Fresh new oil gives you faster response / gear change.
1st and 2nd gear are very low gear and lots of torque, it will have the most "jerk" when you apply enough accelerator pedal.
My tranny cold ( 30C / 88F not any colder
) is always OK. Your cold is how cold ?722.9 Transmission Gear Ratios
First – 4.37Second – 2.85
Third – 1.92
Fourth – 1.36
Fifth – 1.00
Sixth – 0.82
Seventh – 0.72
Reverse 1 – 3.41
Reverse 2 – 2.23
Source : https://www.transmissionrepaircostguide.com/722-9/
The Best of Mercedes & AMG

Best wishes
Joel





Best wishes
Joel


