shuddering tranny

Alright guys, My 95 Windstar GL has been a tough little beast since I bought it from the original owner that kept meticulous records on her services ( I have a folder full of oil changes tire rotations etc etc). Now it seems perhaps the tranny is going to take a dump on me. It has started shifting HARD from first to second and when cruising along at any normal speed the trans will start shuddering real bad, then give it some gas and it smoothes out, I have tried lucas tranny oil and sea foam, I have never changed the trans fluid in the year and a half and 20,000 miles I have owned the van, however the previous owner had it changed every 40,000 miles. The fluid looks brand new and smells good. Should I flush and re-fill? Does anyone have an opinion on the new method of back flushing with the snap-on trans machine? Supposed to be the "new" thing no filter change just a reversal of flow pushing all the old fluid out and replacing it with new supposed to be better than taking the pan off because it flushes the trans cooler and tourqe converter too? ........................any comments?

If you get it flushed make the change the filter too... I had a chemical flush done on my '92 E150 that helped for about 6 months, then it was back to shifting bad again.. We finally changed the fluid and filter and that cured it.

We had this happen on our 1995 Mustang. Ended up needign the torque converter replaced (luckily under extended warranty). We've got a bit of the shuddering on our 2001 Windstar, have for awhile, but we're ignoring it as long as we can, no extended warranty on this one. It does tend to come and go, and it's not nearly as bad as the Mustang was, but it has the same feeling, like you're driving over rumble strips as it's trying to shift at low speeds.

Hmmm... these are the same symptoms that our '96 had right before we had to have the tranny rebuilt. Sorry.

Hmmm... these are the same symptoms that our '96 had right before we had to have the tranny rebuilt. Sorry.

Do a search on the neutral saftey switch, it feed the computer information, some report it fixed trannys that had been diagnosed by shops as needing rebuild

I would try a fluid change....make sure that Mercon (NOT Mercon V) is used. The filter is not expensive.....
Most shops use a fluid "exchange" machine. The machine adds new fluid at the rate & amount that the old fluid comes out.
I do not recommend any "backflush" of the transmission.....a backflush of the radiator mounted fluid cooler is OK. Also, it would be best to stay away from additives to the transmission fluid.

There are a lot of threads in this windstar room about how to change the fluid.

My 99 Windstar had the same condition. Torque Converter was the problem. Had to rebuild trannie. Also, when the car was new it had a vibration (slight) at 30 an 44 mph. The mech thought it was a tailpipe rattle but it astill exists and it is definately trans related