Overdrive Not Engaging

[Panther]

Was driving Healey the other day, tried to engage overdrive, but it did not kick in. I pulled into the garage and checked overdrive oil. It was at minimum at bottom of dipstick. I filled it with 30 weight oil. Took car back on road. Overdrive still not working. I heard the click of the solenoid, but the overdrive was not engaging. Not a lot of miles on overdrive. Did not drive vehicle with overdrive oil low much at all. Any ideas on what it could be? Car has very low miles.

 

[Bob_Spidell]

Since your solenoid appears to activate your electricals are working (which is the most common cause of O/D problems). Minimum oil should be enough to prevent damage, so my first guess is your oil got aerated, which could prevent sufficient operating pressure (like spongy pedal when brake fluid gets aerated). Let the car sit for a day or so, then try again; if it still doesn't work then it could be the hydraulics, but those don't usually fail without warning (slower and slower engagement).

Another (better) possibility is your solenoid is working, but the lever that rotates the cross rod that opens the activating valve is slipping on the cross rod; this could happen suddenly. You didn't mention what model Healey you have; earlier cars have this lever exposed, but later cars have this enclosed, and I don't know if you can get the cover off the box in situ. If the lever moves but the cross rod doesn't you have your answer; you will need to adjust and tighten the clamp on the lever.

I'm not sure what you mean by "Car has very low miles;" some have taken to resetting the odometer after doing a restoration (it's not hard to do). Healeys with less than 50K 'true' miles are pretty rare.

 

[Panther]

Hi thank you for getting back to me car was Total Restoration in 1979, 5000 miles on it since then, Austin-Healey 3000 Mark III.

 

[John Turney]

I agree with Bob, that it could be the operating lever under the solenoid could have slipped.

Another possibility is that the click you are hearing is the overdrive relay on the firewall and not the solenoid. It's best the check the sounds with the engine off and the key on, unless you have a Pertronix ignition which doesn't like being powered on without the car running.

 

[Panther]

I agree with Bob, that it could be the operating lever under the solenoid could have slipped.

Another possibility is that the click you are hearing is the overdrive relay on the firewall and not the solenoid. It's best the check the sounds with the engine off and the key on, unless you have a Pertronix ignition which doesn't like being powered on without the car running.

Thanks