Code 740 being told clogged filter??

[beachrights]

2001 C70- just replaced the Valvebody (remaufactured from Sonnax) 300 miles ago due to delayed engagement and harsh shifts. Transmission ran like new....until yesterday when I felt weird shifts when starting out then 3 miles in car started bucking like a wild horse and tranny was slipping. Went into limp mode and flashing arrow.

Codes 740 and 1618 Figured I had a bad Solenoid in the valvebody. took it back to Transmission shop and he thinks its a clogged filter since it drives 'ok" but gets worse as time goes on. 4 miles and its horrible.

This means dropping the transmission and a huge bill. I just spent a ton of cash on the valvebody and throwing more at a "maybe" considering the recent repair is not sitting well with me.
I'd like to trust him but the 740 code is way off on this right????
Thanks

[abscate]

Look up the thread About a cheap way to bypass the internal filter without opening the transmission, it involves drilling a hole to puncture the internal filter and installing a Magnafine