what faults are stored in the car's computer?
what warning lights are on the dash?
what exactly did the transmission shop do to try and fix it?
I had another german car expert in Keynsham look at the car and he seemed to indicate a problem with the electronic chip but that the only solution is a new gearbox at about £1500. No warning lights are on. As to the exact details of what the transmission specialist did, I just don't know. They simply said they were rebuilding the box or rather building a new box from scratch. I am a total amateur at mechanics and have no idea what they actually did.
I'm sorry, I just don't know. They simply referred to the 'electronic chip controlling the gear changes' and that this was a well known fault with BMW 5 series models 1996 to 1998.
I have found the Bristol Transmissions invoice and they charged for :-
1. Remove and install transmission - 3 hours.
2. Recondition ZF5HP18 auto transmission and torque converter.
3.Supply and fit oil cooler assembly, transmission ecu, gear lever assembly and throttle body.
Hope this helps but if not then I guess we had better call it a day.
A quick follow up - perhaps the guys who said 'chip' meant 'ecu' and were simplifying it for me - just a thought.