I have older threads out there talking about my transmission problems. Fast forward to present. I had the tranny rebuilt last fall. Supposedly they tested the valve body and solenoids and all was ok. The tranny no longer bangs and clunks, but it still does not shift right after a LONG drive on the interstate followed by start and stop driving in stoplight traffic. Does not want to up shift until it hits high rpms. When it does shift, it is very smooth and nice. When you slow down, it downshifts and the problem repeats. All shifts are smooth, just wrong.

I pulled the valve body out today. Easy job. I need to send it off to be inspected/tested/rebuilt, including the solenoids. I suspect there’s a microscopic crack or something that is allowing pressure to bleed off, fooling a solenoid until rpms get up enough to trigger the shift. My theory is that the fluid gets good and hot, and eventually thin enough so that it seeps thru the crack or a tiny defect in the solenoid O ring. I don’t know much about transmissions, but just trying to think my way through what the issue could be.

Does anyone know of a shop that can rebuild the valve body? Google shows some options but I prefer first hand recommendations if anyone can help. Thanks. I’ll get it figured out eventually.

P.S. I had more luck when searching for Mercedes 722.6 valve body. Seems they used these transmissions until quite recently.