Recently I was reading somewhere (I can't remember if it was here on the board or in a service manual) about "releasing" the overdrive before removal. I perused the recent messages on the subject of OD but couldn't find it so I think I read this elsewhere. And I don't have my service books at hand at this moment.

Anyway it went something like this. Drive the car and, after reaching top gear speed, engage the OD. Then while still in fourth and OD working push in the clutch and disengage OD. Then drive home or wherever and remove the transmission/OD.

What is that all about? I'm getting ready to drop the M-46 out of my '84 for future transplant into my '80. Do I need to worry about this? Is this procedure only done if you're going to dismantle the OD unit for repair? I really don't want to drive the '84 because the tags are expired plus it is very loud due to an exhaust system problem.
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'80 DL 2-door

I looked too. But I didn't see it in Haynes. Small wonder, my old edition of their 240 manual is so poorly edited they probably don't tell you about this until after they've given the procedure for tranny removal. Bentley gives this info and that's where I remembered seeing it. Also the much reviled (and I quite agree) Chilton's manual describes releasing the overdrive although their method varies slightly from Bentley.
But my big concern was if I needed to do the release if I am not dismantling the trans/OD which I'm not. So I guess I won't worry about it. But you learn something new every day.

Thanks to those who responded.
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'80 DL 2-door

From my Volvo shop manuals: "It is important to avoid torsional stresses in the shaft between the planetary gear carrier and the one-way clutch. Prior to removing the overdrive, it is advisable to drive the vehicle with the overdrive engaged and then disengage with the clutch depressed" The official Volvo word.

If you are not separating the trans and OD there's no need to worry about any of this.

It is only if you are separating the overdrive from the gearbox. If you are taking the whole tranny off you don't have to worry about it.

Just use the clutch to stall the car while in reverse. Otherwise it is very difficult to seperate the od unit from the transmission. At least that is what I remember from my research before I removed the od from my 82 turbo.

Randy

Well, I hadn't heard of this either but since you asked I looked it up.
Haynes says:
"It is helpful, before removing the overdrive, to start the car and engage and disengage the overdrive with the clutch pedal depressed. This will avoid leaving any residual torque in the mainshaft, planet carrier, and unidirectional clutch."

There you have it.
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Rob Bareiss, New London CT ::: 86 244DL, 87 244DL, 88 744GLE