transmission hard shifts code is p1811 , so far cleaned MAF sensor
added Lucas fix , if it happens again can I add 2oz OF SHUDDER ,I erased all codes and its OK going on 3 days ?
That might buy you some time.
But I suggest you watch the video from Mac Gyvers Workshop on a possible fix.
I would not attempt it myself, but would find an independent transmission shop, not a chain store.
The trouble may be with the solenoid.
Tester
2003 Buick Lesabre 3800 V6 70K only on it. it comes and goes, it seems
when the engine is hot normally on a log days run it starts with the hard
shifts, however when I go real slow and slightly step on the gas at say 3-5
MPH I hear a slight engine compartment rattle like a PCV valve in which I
took out and cleaned like new , it did this before I cleaned it also . I cleaned
the MAF sensor the MAP sensor. in neutral rolling and revving the engine a
little it don’t make the noise only when put back into drive gear. what can
this be with no engine check light yet. and when I do not hear the rattle
noise it shifts smooth ? .