If the mileage is high it may be worth getting a Sonnax main pressure valve fitted. Worth doing a vacuum test first, but I find that I need to replace quite a few.







https://www.youtube.com/watch?v=54gBRA_yMnM

https://www.youtube.com/watch?v=jm_M4hk1YHI

https://www.youtube.com/watch?v=MZH3BkKlNfM



Unlike the 6-speeds, the solenoids on the 5HP24 are generally very reliable



Based on your symptoms, it’s also worth checking that your upper valve block doesn’t have a crack in the SV-1/KV-F circuit





Phil