Overdrive slow to engage

[Frank C.]

Greetings and I hope our friends on the Atlantic shore are weathering Irene without any losses.

I noticed that my OD is slow to engage while in heavy acceleration. I have to let off the gas and then all is well. Any ideas on the cause?

Thanks and take care.

 

[TimK]

Do you mean that it begins engaging, but does not complete the shift, or it does not begin to engage while you are accelerating? If the former, you may not have sufficient oil pressure and may have to clean out the accumulator (accessible from the side panel with the tunnel off). Or, you may have excessive wear in the OD clutch so that it cannot engage under heavy acceleration. That would require a complete overhaul and replacement of parts. I have not experienced this, so others may need to post to confirm or change my diagnosis.

 

[Frank C.]

Thanks Tim,
The OD works fine under normal acceleration but as I push it harder, it won't engage until I let off the peddle a little. Does that explain it any better?

 

[GregW]

That sounds normal . Isn't that what the overdrive throttle switch is supposed to do?

 

[Keoke]

That sounds normal . Isn't that what the overdrive throttle switch is supposed to do?

Yeah!! I think you got it bout right--------Keoke-- :laugh:

 

[John Turney]

I thought the throttle switch prevented disengaging unless the throttle was open a certain amount. :confuse:

 

[RAC68]

I believe John is correct and the switch prevents disengaging on deceleration when the throttle is closed.

Have you changed or added Synthetic fluid recently?

If so, the synthetic could be seeping past the shaft O-ring into the enclosure housing the solenoid with oil getting into its piston chamber. If this is your issue, just remove the cover plate, empty the enclosure, and clean the solenoid piston and bore. Leave the oil as it will have fallen below the O-ring on the shaft and work fine.

Since the solenoid is responsive when not accelerating, I would check the voltage to the solenoid to make sure it is proper. If so, I would guess the solenoid is going bad as it works unstressed but hasn’t the power to operate properly when under stress.

Hope this helps,
Ray (64BJ8P1)

 

[Keoke]

I thought the throttle switch prevented disengaging unless the throttle was open a certain amount. :confuse:

Yep he is just going past the "certain amount"--Keoke

 

[Frank C.]

Ray,
No, I don't use synthetic oil and the levels are good (as is the color of the oil). I am thinking it may be the solenoid too but I'm not sure how to est it. So far this is not a "show stopper" for the driving season but I want to work on it as soon as possible.

 

[IanIrving]

Go to this link and look for overdrive. Fascinating article that should have all you need.

Ian

https://www.team.net/www/healey/tech/big_hly/index.html

 

[Frank C.]

Great link, Thanks Ian! I'll start my education tonight