tripleflip

Hi all, I own a 1996 Mercedes-Benz c280 and my transmission has been giving me problems since I purchased it. I purchased it aware of the transmission issues, the problem is that it doesn’t shift into 3rd and/or 4th. It’s a 4 speed automatic transmission 722.4 and once it hits 3rd going into 4th is impossible RPMs go up but gears do not catch and there is no acceleration. Previous owner was selling as is and didn’t know what the problem was just that gears were slipping and it “wouldn’t go faster than 40mph”. I have thought about replacing it with a refurbished or donor transmission, alternatively I could potentially have it rebuilt but I’ve also heard it’s possible to swap the auto trans for a manual trans from a w203 the 6 speed specifically. If anyone has any advice on repairs and/or swaps it’d be greatly appreciated.