As the title mentions, I have a 2003 Dodge Grand Caravan, and my transmission sometimes downshifts forcefully with a clunk when I let off the gas. It will do this no matter what gear I'm in (except 1st of course), and depending on speed and gear, it will jolt me forward in my seat. If I put the slightest pressure on the gas pedal, it will up shift into the proper gear.
I've been driving back and forth between FL and MA (a distance of about 1,300 miles [~2100 km]) a couple times per year, and this is what brings on the issue, which will persist for a week or two after the trip. Additionally, it seems to be related to the speed I travel on the trip between FL and MA: If I go slower, it either won't come up or if it does, it will last a shorter amount of time (I.E. a few days rather than a week or two).
If I keep a slight pressure on the gas pedal and brake with my left foot, it does not do the hard downshift.
I found this post, which is similar, except my speedometer doesn't fluctuate, I don't have cruise control, and it happens in all gears, not just second to first.
Does anyone know what is causing this, and can you please tell me all I need to do is tighten a bolt (an easy to access bolt)?
Edit:
@JPhi1619, it has about 121,000 miles (~194,730 km) on it, and I changed the fluid/filter at, if I recall, around 70,000 miles (~110,000 km), right when the owner's manual recommends replacing trainy fluid.
@Rana C'mon man... no bad news please :P