harsh shift in all gears----up & down

I have an 2001 SC1 with only 130K miles. It recently started shifting harshly. Shifting from Park to Reverse or Drive is usually OK, but when driving, every time it shifts up or down it slams into the next gear---makes your teeth fillings fall out it hits so hard.

Already changed the fluid and filter twice. Was planning to now replace the TC Solenoid and Pressure Solenoid, expecting those parts to fix the problem. Am I on the right track here??

Any advice or suggestions would be appreciated

Replace the ECTS first. The ECTS is vital to many sub stations including tranny functions.

Also check the charging system. These trannys are very sensitive to proper voltage levels