I have 11k miles on BS and I always drive in Manual mode. Recently I noticed that when the car is cold and I shift from 2-3 in low rpms (3k or so) the engine revs up a few hundred rpms and drops down. After the car is warm it seems to shift fine.

Anybody ever experience this issue? Do I need a new transmission already?

I experienced that every now and then on my regular C63 during the winter time but only in first or second. Never a problem in the summer though.

I get this a little bit when the transmission is cold. Usually on the first shift that the car makes from 2-3. I only warm the car up in C mode though. After the first shift the "flaring" that occurs does not happen again. I always thought it was just normal operating for a cold transmission to slowly swap into the next cog when the fluid is a bit thicker.

That is normal when the car is cold, TCU is desing to do this in order to protect the tranny until everything is up to temp.

Hmm, I've never had that happen to me before though? I wonder what it will take for the dealer to give me a new tranny?

depends on what exactly is wrong with it. If it actually has an issue it's probably software related or a valvebody problem. considering all your mods. You can forget about them just giving you a new transmission.

I get this is the morning, too. The first shift from 2-3 in C mode always sounds like it's slipping. After that, it shifts normally. I've brought it up to the dealer, and they've told me that they can't replicate it, and that it's probably the tranny warming up.

I have about the same mileage on my BS and I get the same thing. From my basic research it seems that the transmission/TCU adapts to my driving and tries to slip a little to maintain grip levels. I attribute my slippage to that effect.

The transmission pulls hard in any other situation so I didnt give it much more thought, and moved on with my life.

It does from time to time still seem weird (being used to dual cluth transmissions which feel more connected in the low speed arena), but when Im driving spiritly the BS doesnt have that slip feeling at all. If you find out there is actually something abnormal, let us know.

Thats good to know! Thanks for the info. I always drive my car in Manual mode.

Also I noticed that if the car is cold, the downshift from 4 to 3 is very rough