This is an adaptive learn transmission controller or ECU. If you are driving it hard for a few shifts it will start shifting firmer (it increases line pressure to help it live longer from a heavy foot)then you drive it easy it will take 20 shifts or so to start smoothing things out again. Drive it easy for a week and see what happens.--------------------------------------------------------------------- I seem to be having an intermittent problem with 4th gear on my 1987 735i (ZF4HP22EH Transmission). Most of the time it is fine, but every now and then 4th gear is engaged quite harshly. It seems to occur more under normal / gentle driving than hard acceleration. There doesnt appear to be any real regularity - it happens some times, but not others. Ive recently cleaned the wiring connectors - that made no difference. The oil and filter are new, and the oil (Mobil 1 Synthetic ATF) is at the correct level. The only other thing I have noticed is that occasionaly after pulling up and selecting reverse it shifts a l;ittle bit roughly too. That happens only on the odd occasion. Any advice would be muchly appreciated. Craig 1987 735i 152,500km