My transmission shifts hard at higher rpm. I replaced fluid, plug (where the leak to the computer harness takes place), filter. Got the fluid exactly where it should be. It still shifts hard. Btw, it shifts normal below 2500 rpm.

So, I have to bring it in. Does it sound like a seals issue with the gears, or a valve body issue. Anything else I can try before bringing it in for repair.

I have 165k on this transmission, is it best to simply get a completely overhauled transmission rather than to repair whatever this issue is?

Thanks!!

__________________
2008 S550
2010 GLK350
1997 E420 (retired)
2005 CLK500 (retired)