Transmission moves but will not change gears as though its sliping

Broken synchronization ring inside transmission most probable cause, however check detent spring and balls, shifter first, if they are good transmission will have to be stripped and inspected...

What was the actual trouble code ?

Here's a video Victoria Engwall-Rosiello suggested as a solution to your problem from YouTube:


Transmission Shift Solenoid

Check transmission fluid level Hot in D. Over full will cause frothing and loss of pressure in the system. Have a transmission pressure test done . It may need a band and clutch pack adjustment.

Your going to have to take the truck to get the transmission changed, change it now before it gets worse

Re-check the transmission fluid level. It's possible that the level has "settled" due to the work that you did on it, and may be low now, even though it appeared normal when first topped off.
Just a thought.

Best regards, --W/D---

could be throw out bearing any vibration?

Bring the vehicle to a transmission repair shop . Whats happening is the stator in the torque converter is not building up the torque you need to shift or move for that matter. Time for a rebuild or new trannsy or car.

did you change fluid and filter this is just as important as an engine oil change. also a automatic transmission has things called bands that change the gears and hold overdrive in they also need adjusting every 30,000 miles. if not they will cause your transm,ission to slip. and burn up atf fluid.

Probably a modulator, however check that the "bowden" cable is properly adjusted (this is the cable that does the "kickdown" and also goes to a vacum /valve.It is simple to adjust, basically with the engine turned OFF, check that the 2 pointers (like arrows) align, (one is on the cable). Being a merc it pays to have the tranny properly serviced, and its filter changed at least every 2 years though merc says 60,000k's. And the one thing that will kill a merc transmission is the WRONG oil, it has to be according to the spec sheet which is in your user manual.(lots of tranny shops use anything!)
Also check the dipstick for discolouration/and or burnt smell.