GLC 63 shfit hard from first gear to 2nd
 

I accelerated to 5000rpm in the 1st gear and shift it to 2nd
and there was a huge jerk back when I shift it
I think this is this not normal right?
only 5000 miles
Brand new glc63
should I bring it back for inspection?
and yes the car is warm up already

Take the car back!

If in Sport+ it gives a pretty hard shift.

I just did the rear differential oil swap at my house. It feels a bit more buttery.

Same here. What I found out is, that it only happens in Manual mode. Never happened in AUTO mode.

It even happens in lower RPMs. It is so noticeable clunk, that I only do hard acceleration from 2nd to higher gears in manual mode...

Does anybody know why it could be?

I have 2018 GLC63S

This is literally just how AMG cars are in S+. Doesn't make much sense, I agree. It feels like there is a problem, when there's not.

Did everyone just accept that this is how it’s supposed to be? The 1-2 manual shift in sport+ feels like the transmission fell out of the bottom of the car. The rest of the gears are completely smooth. I had my fluid changed just to be sure and it’s the same. The weird thing is that one out of every four or so shifts, the 1-2 is very smooth (still fast). If the car is built for it and can handle it then great. The problem is that once you tune the engine it’s much harsher still (due to the extra torque). I’m just worried about longevity. I wonder if any tuners can soften this shift with a tcu tune

A faulty TPS sensor can also cause hard shifting-at a minimum I would scan the car and check that no codes are tripped.

Likely due to the Tires. As crazy as it sounds.
I posted about this a year ago & got no reply's. I installed M-PS4's and like magic no more clunk in the right rear on hard accel. (Tuned to 625HP)
If running all season hard compound rubber i believe the wheel is spinning a bit & the tranny is catching. I would get this occurring between gears 1-2 & 2-3.
Now that a few more people are noticing this, is it coming from right rear primarily?

No more spinning all 4 wheels on launch & no more horrific clunk during the 1st few gears.

Clunk
 

I occasionally get the clunk when switching the engine off, as if it was changing gear, but not while driving…

Wow I think you nailed it! I bought the car with Michelin Latitude all seasons and the issue was terrible. Just bought some used wheels that came with PZeros and the problem disappeared—perfect shifts. Transmission tune is flawless now. Hopefully this helps others!

Edit: I’m still having rough 1-2 shifting, but not as bad. I think it is traction related

When I initially experienced this repeatedly, I took my sweet ride in to be diagnosed. After days missing her while she was at the dealership, the mechanic could not find nor get my ride to replicate it. So they asked that I take the MB mechanic for a joyride. We drove the neighborhood and hopped on the freeway. I drove like I normally do, in beast mode. Of course she was on her best behavior. Then she finally replicated it. The moment it happened and I pointed it out, the mechanic said it was the wet-clutch. So the clutch is in 2 gears simultaneously. It is only with further acceleration/deceleration that it then commits to which gear it will drive in. This is an intentional design and characteristic of the AMG GLC.

Once you learn this about your car, you will alter how you engage the ignition. Your foot will feel this dance and the 2 of you will fall in love with one another. Yes, you gotta take her on a few dates first, allow her to lead, feel her teach you, then she’ll let you slide into her silky stuff.