I posted the whole story on the Engines and Transmissions thread, but just a general question here. I syphoned off about 3 liters of transmission fluid and replaced it. No flush, did not drop the pan. Then 2001 Blazer went into limp mode. Gears 1 and 3 only. Replaced speed sensor and both shift solenoids. Still in limp mode. Did not touch anything else. After one mechanic and AAMCO told I need a new transmission. Question is what did putting 3 liters of fluid do to the transmission? Thanks.

 

Some will say adding new fluid with its detergents will loosen any grit on the clutches allowing them to slip if they are old. Also, if you've been having any issues with your transmission then it could just be a coincidence as once they start failing, it the process from kind of working to complete fail can be pretty quick (within a week or so).

 

Did you give them a call?