Recently acquired. Runs great. Shifts from 1st to 2nd around the 1st dot on the speedo correctly then almost immediately shifts into 3rd and with 5-10 mph more upshifts again into 4th! All this while I have the accelerator floored. This transmission doesn't have vacuum. Any suggestions about how to go about adjusting/checking things? I haven't come across any online manuals or other resources that address these transmissions. I'm sure someone has had experience. Please help. I notice a four prong plug on the drivers side, should I be checking things there? What about the pressure control rod from the IP to the lever on the passenger side of the trans. What does the item next to the pressure control lever with a wire going to it do? PO has records of all service and shows regular fluid/filter changes. Fluid seems fine and level is good.

 

I would verify no wasted motion in the linkage to the trans i.e. bushings pins etc. Have someone slowly depress the throttle while you watch the movement of all related linkages. any slop would give late pressure changes. If thats ok, then I would lengthen the rod to the trans thru the adjustment provided. Make note prior to adjustment so if necc you can return to that point. a longer rod should boost control pressure raising shift points. Do it in small steps, it shouldn't be that far out. These opinions are not MB specific but relate to most transmissions that rely on control pressure rather than vacuum modulated pressure.

 

Did you get the trans adjusted. other forum members can learn from what you did to fix it, thanks.