The AR25 was free, so fitting it was agreed as the next step in the diagnostic process.
We had no way of being sure a box change would cure the problem..if another electronic problem existed.. so why spend cash on an AR35 if it would turn out to be a waste and not fix anything?
Our thinking was, fit the AR25, and see if it cures the problem. Which it has. So... rather than a drive a car that's not safe and only pulls away in 3rd gear (not good with lorries etc).. I now have a working car to drive, while I source a decent AR35.
I also have now have had the experience of changing a box on my own.. which has been invaluable (even with the aches and pains!)
In fact, the gearbox is working sweetly. It's going to have an ATF change in the next few days, and I never drive my cars very hard, so I don't envisage any problems for the forseeable time to come..
Yes yes... rip me to bits.. but from a cost (and very low value of the car) option.. it was the only real financially viable form of troubleshooting!
AR25 = handles 250nm torque
AR35 = handles 350nm torque
Logic says that with new ATF, driven sensibly and not towing.. shouldn't result in an immediate failure while I shop for a low mileage AR35...