Fleetwood

Let's try this again. I bought an 02 TL-S with 30k milage, and see (saw) all those transmission problems noted here. Mine shifts poorly. Sluggish from 2nd to 3rd...especially when cold but other times too. Slow, sloppy shifts otherwise. Thought I'd get a flush with the 30k service...will it help? When other's trannys crash, do they do it all at once? Is manually shifting better...or worse...on it?