I took a three hour drive last week and the car behaved just fine. The day after I went back home and the OD started to disengage, then engage, then disengage etc until I switched back to Normal. Checked transmission oil level and it was fine, just under Max. I diagnosed the electrical circuit as per advice found on the Healey6.com site and everything seems to work. I hear the solenoid engage when I have ignition on, switch to Overdrive and put in fourth, it releases when I put the gear in neutral and stays engaged when I keep it in fourth gear until deactivated by the throttle switch. When I drive and it disengages it does so in a “crisp” way, not sluggish, which I understand suggests electric rather that hydraulic/mechanical problems. The transmission and OD were rebuilt by the PO two years ago so it should not be worn. Can the solenoid become “weak” so it engages but can not hold up against the pressure when the car runs? I measured the resistance between the white cable going down to the OD from the relay and earth and it was 2.5 ohms. I have not been able to measure the current because my multimeter can only handle 10 amps and I understand that the current can exceed that (although 2.5 ohms suggest a lower current, but I assume that there may be a stronger spike/transient upon engagement of the solenoid). Will get a better multimeter.
Any advice would be appreciated.
Any advice would be appreciated.