97 s10 4l60E overdrive issue

[Dr Bowski]

97 S10 2.2L with an 4L60E it shifts fine 1-3 once it hits overdrive it slips but also feels like brakes are lightly being applied. I had the trans serviced and the shop told me their was no metal or anything in pan to indicate something broke and all solenoids are working properly does anyone have any ideas

[00Silverado4x4]

Could be an issue with the torque convertor. My only suggestion is to take it to a good trans shop to have looked at/diagnosed.