Strange Trans Problem
 

Hi all,
I have done a search but can't find anything like this. It is a 91 300D 2.5 with a 722.418 trans. If the engine is running, you can't shift into Rev or Park. With the engine off, this doesn't happen. If you start it in park, shift to reverse, every thing is fine. Shift to D and every thing seems normal. If you stop and try to put the shifter in reverse, the stick will not go into reverce. Any one have any ideas on this? The car only hase 295,000 so I don't think I should be having transmission problems (ha, ha). Seriously, the trans has been working perfectly, no slipping, no flaring, good ferm shifts, etc. This started all of a sudden, with no warning.
Thanks for any feedback anyone may have.

All 722.3, 722.4 and 722.5 transmissions have a safety feature which inhibits a shift into “R” or “P” when the car is moving. At or about 9 mph governor pressure actives a hydraulic piston located in the secondary valve body, this piston blocks the manual valve from moving into the “P” and “R” position. Install a gauge in the governor port, the reading at a stop is “0’. Governor pressure is usually ½ of road speed, round off 9mph to 10mph, if you read more then 5psi the governor is bad or the governor bore is worn(case), if not there’s a problem in the secondary valve body.

C32AMG

YOU DA MAN

I didn't check the pressures be cause I don't have a pressure guage, but I did remove the governor and check but didn't see anything wrong so I washed it real good in new parts cleaner. Reinstalled it and everything worked fine.
Thanks you VERY much for the information.