seads wrote:
> I have a 1985 Volvo 240 with a manual transmission w/ push-button
> overdrive. The overdrive has not been engaging and here is what the
> car will do when attempting to shift into overdrive:
>
> Driving in 4th gear, I press clutch and push overdrive button
>
> Hear relay click, light goes on, release clutch
>
> Overdrive does not engage
>
> If I let off the gas, the RPMs drop to about idle and I can feel the
> tranny trying to grab a gear as the car makes a jerking action.
>
> If I get on the gas again, the RPMs resume what they would normally be
> in 4th gear, but overdrive has not engaged.
>
> I have checked under the car at the solenoid to listen for a clicking
> sound when OD button is pushed w/ key on, motor off and I can hear the
> click.
>
> Any help on this issue would be greatly appreciated.
>
> PS...once in a blue moon, the OD will actually engage but after about
> ten minutes it disengages and will not re-engage.
>

As the FAQ someone else linked implies, check the oil level
first. If that's ok, the O/D solenoid probably needs to be replaced.

mjc<DELETETHIS>13 wrote:
> seads wrote:
>
>> I have a 1985 Volvo 240 with a manual transmission w/ push-button
>> overdrive. The overdrive has not been engaging and here is what the
>> car will do when attempting to shift into overdrive:
>>
>> Driving in 4th gear, I press clutch and push overdrive button
>>
>> Hear relay click, light goes on, release clutch
>>
>> Overdrive does not engage
>>
>> If I let off the gas, the RPMs drop to about idle and I can feel the
>> tranny trying to grab a gear as the car makes a jerking action.
>>
>> If I get on the gas again, the RPMs resume what they would normally be
>> in 4th gear, but overdrive has not engaged.
>>
>> I have checked under the car at the solenoid to listen for a clicking
>> sound when OD button is pushed w/ key on, motor off and I can hear the
>> click.
>>
>> Any help on this issue would be greatly appreciated.
>>
>> PS...once in a blue moon, the OD will actually engage but after about
>> ten minutes it disengages and will not re-engage.
>>
>
> As the FAQ someone else linked implies, check the oil level first. If
> that's ok, the O/D solenoid probably needs to be replaced.


And if that doesn't work, the piston seals in the overdrive are probably
shot, or something major is broken.