transmission problem? help please

recent problem, i think tranny... car is auto 95. and tranny only has about 25K miles on it, when shifting to second and maybe 3rd, if im just normally driving, like around 0 boost to get car going, right before it shifts into 2 or 3, it will start to vibrate, and then shift. not a huge vibration just a little rumble. it doesnt do this every time though and if i go into about 5+ boost to get going from a stop, it wont do that vibration, never does it when boosting, and again, not even every time during normal driving. it usually shifts nice and smooth, and i have no idea whats up,, i could only come up with the idea that it's the tranny,,, but it's fairly new so i got no clue.. any ideas, please help. thanks-
DAmon

the vibration is throughout the whole car, or do you feel it most in the shifter?

i feel it throughout whole car, like the steering wheel and my whole body can feel it. might that rulr out tranny? the engine only has about 30-35K miles on it, car's been well taken care of and never been in accident. ideas? thank you--
Damon

update

update.. ive just noticed yesterday when it shook one time that i did NOT feel any shaking in the shifter, i felt it mostly on my feet and the steering wheel, rule out tranny?
thanks

Sounds like you have the famous shudder, which is due to the inferior torque converters Ford put in the earlier 4R70W trans in the '94-95 T/birds. The real answer is to replace the TC; but Ford's last TSB on the subject recommends completely flushing the fluid. It worked succesfully on mine when it happened (at around 25,000m) and I also now use the newer Mercon V fluid. You can do it yourself by draining the TC as well as the pan.
You should also look at the very good articles on the TCCOA site regarding the weaknesses of this trans (pre '96) and consider replacing the following parts: Accummulator pistons. MLPS. Solenoids; re-building the Valve Body or installing a shift kit (like Transgo) and installing the bigger 1996 pan & filter.
Good luck.

wow

awesome, thank you, sounds like it could be it, you know exactly how i go about flushing the fluid? where is the plug? every time ive tried to do something without consulting others completely, i end up breaking something.... thanks a million and also......
WIll it be a problem if i continue to drive it like this?? it's been happening for a few months and hasnt gotten any worse,, it's my daily driver...
Damon

If you have the stock pan there is no bolt/plug, you just have to lower & drain it the old fashioned way (that's reason enough to upgrade to the bigger 1996 pan with the drain plug). As far as draining the torgue converter is concerned, just remove the round rubber bung from the bottom of the casing and using a big breaker bar & socket on the front crank bolt - rotate the engine until the little drain plug appears at the opening. Just remember that the pan only holds about 3 quarts, whereas the TC & lines carry like another 9 qts (so you need a BIG drain pan). To do a real thorough job you can also remove the cooler lines from the back of the radiator, so you drain those too.
When you re-fill, just add about 3 qts at a time through the dip-stick tube, start the motor, quickly run thru the gears & shut it off. This way the fluid gets pumped into the TC. Once you've poured in 9 qts, maybe just add 1 at a time until the dip-stick shows in the cold zone.