2 cars in one week, won't shift into 4th gear - PeachParts Mercedes-Benz Forum

ROLLGUY · #1 08-24-2015, 11:11 AM

Both of my niece's cars ('82 300CD & '81 300D) quit shifting into 4th gear in the same week, that is just weird. They both will shift just fine up to and into 3rd, but stay there. The cars will only go about 45 MPH without revving them too much. The CD has a 722.3 (I think), and the D has a 722.1 (vacuum only). I have not had the time to look at either car, and my brother has no idea about transmissions (I'm not far behind him). I have heard that a fluid change and adding Trans-X or the Lucas product will help, but I am not sure if that will fix the problem. Both girls love their cars, and would not like driving anything else. Anyone have an idea of what to do? Is the fluid change worth the effort and expense? Thanks in advance, Rich