[Mr. G]

2001 Grand Prix which I took to the dealship to have fluid in transaxle changed as part of routine maint. They recommended "flushing" the system which I gave the OK for. Since then, the trans shifts hard on occaision when it reaches operating temperature. I read that flushing the system is more harmful than good and that other people have expirienced the same problems. Anyone have such a problem, and is there a remedy that will cure the hard shifting? Thanks! Mr. G

[salem1912]

Did they change the filter? AAmco and others now tee into the cooler lines and flush which may stir up things that should not be as they are already passed the filter. Also ask if new fluid was used, I've heard that your old fluid may be filter in the machine and sent back into your trans. It's always best to drop the pan and change the filters.IMO Tom Same goes for these "oil flushing machines" only use as a last resource i.e. knocking lifter noise.

[Mr. G]

Update: After the hard shifting became constant when engine has warmed up, I pulled the dipstick and noticed a strong odor of burnt tranny fluid. Next, I dropped the trans pan and replaced fluid and filter after which the tranny shifted smoothly for approx 1000 miles when it began to shift hard again ant the fluid smelt burnt again. Another fluid and filter change, this time using synthetic fluid. Now I have put about 2500 miles on it since then, but the fluid is starting to get the burnt smell again and it has shifted hard once or twice recently. Any ideas on what may cause the fluid to burn? Would it be possible that the cooling lines to the radiator are obstructed and this is what burns the fluid? Thanks!