94 Grand Marquis Transmission shudder help please

I just got this car running after a few years off the road, 100k miles, changed all fluids.
The transmission has started to shudder under mild load, slow speed around 30 to 40, uphill more.
The fluid level is correct. Otherwise it is perfect except I feel it shifts into OD too soon, maybe its normal for this car.

Drive shaft is fine.

Are you the original owner? Was the car shut down because of the transmission problems? If it was, it may need a rebuild. Sounds to me like gunk is clogging the passages in the valve body. A shop could do a thorough flush out, if that's all it is.

No, not original owner.
The original died, car sat for about 5 years, ran fine for first couple hundred miles. Maybe I'll try draining the tranny again, good idea?

hi why don't you try to bring it to the shop for maintenance? or if you need some auto parts at least they know what is the possible solution for that.

Dude I'm having the same problem I think. I have a 88 crown Vic that has been sitting since 2005. I started driving the car again mothers day of this year. My gma was the first owner of the car. Had the tranny replaced (3rd gear went out) and haven't drove it alot since the new one was put in. It's doing exactly like you're saying with the "shuddering" and it switching into "3rd gear" way to fast. Now it just started doing it after driving it since mothers day. Don't know the problem, changed spark plugs, wires, distributor cap, rotor button, changed the fluids, changed fuel pump & filter. Maybe the next best thing would be changing the tranny filter?!! (just hit me!)

Problem solved, changed the fluid to just Mercon V , drained the torque converter too and have driven the car through the mountains in the snow the last week, 1000 miles, no probs

Glad you solved it. Sometimes we forget that a lot of the trans need to use a specific fluid

Try running a 5-speed manual that has to use Mercon for fluid. Gear oil don't work!