That would make it a J type. When they get old the solenoids can sometimes fill with sludgy oil gunk that can make them very slow to respond. And sometimes the O-rings on the solenoid's shaft can develop leaks and let oil past, engaging it when it shouldn't be.

AFAIK the OD unit isn't specced to handle the multiplied torque of the lower gears. I don't think using it as a half gear would be a good idea, nor would shifting it under power. Using it in reverse is much worse, of course (I think there are some bevel gears that pull components together under forward torque but push apart in reverse). Of course in typical Volvo fashion they used a standard part in an understressed application, other manufacturer's cars using the same OD unit typically had much more powerful engines, as did the Volvo 164. But still, in 1st gear that torque is tripled.

Just curious, but it works better as a half gear (ratio-wise)than I would have thought. Ratios w and w/o OD:
(1) 3.13:1 - 2.41:1
(2) 1.99:1 - 1.53:1
(3) 1.36:1 - 1.05:1
(4) 1.00:1 - 0.77:1

PS - On my PV I took out the cigarette lighter and got a matching old wiper switch to replace it with. Looks utterly stock. The wiper switch has an extra position, but as long as it is pulled out the OD is on (in 4th gear). Of course, I forget to turn it off about half the time, next time I'm speeding up again I get the 3rd-to-5th shift unexpectedly. :/

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I'm JohnMc, and I approved this message.