Hello- '99 A6 2.8 (auto) 211,000miles.

Last winter the RPMs would flux 400-500 RPMs when driving up very slight or moderate grades. Sometimes coming down or up a steeper grade it would "slam" into gear. When temps reach 60 degrees or higher all is normal- Even in winter when fully warmed up this issue happens- Its now colder in the NE and same shifting issue have started again. I have searched far and wide for possible similar issues- I read that the solenoid screens could be slightly clogged?? I plan to flush the tranny fluid and change filter- Before I do, is there any thing else i should consider??

NOTES:
1) Tranny flushed September 2012 and every 75k since new with Audi fluid and filter- Magnets were normal as was fluid color
2) New fuel filter
3) New Spark plugs and wires
4) Clean MAF sensor every oil change
5) No codes at all
6) Replaced breather hose- that crazy PVC plastic hose
7) No Oil leaks or other issues
8) Recently check tranny fluid (all good)-

Hoping to get to 300k- Thank you inadvanced for your time

 

Does anyone have the proceedure to clean the solenoids?

 

Does anyone have the proceedure to clean the solenoids? Anyone???