G/box: 2WD: M40 with Overdrive

[jamie]

How is that possbile....an M40 gear box with overdrive?? I thought overdrive required an M41 gearbox, but the label on gearbox clearly states M40. I suppose it might be possible to change the detail of the M40 to make it an M41 but the label remains? Can only an M41 be joined with an overdrive, so if these are as shown in the photo it should all work?
Thanks, yours bemused!!

http://www.ebay.co.uk/itm/Volvo-M40-...IAAOSwjqVZAbyw

[123GT-AMAZON]

Hi ya Jamie ,

Simple answer a owner has had it upgraded so rebuilt with the new components

Long main shaft
Adapter plate to suit that gearbox and Overdrive unit as J & D type differ
Bolted on the Overdrive in question
Used a Overdrive speedo cable
--- naturally used the front short prop section to suit output of the gearbox Overdrive end ---

And bobs ya uncle you have a converted M40 to a hybrid M41 Overdrive gearbox

Apartently the oil filler plug sits at a different height aswell so check your oil Correctly if your runing a hybrid !! Gearbox in your car .

All the main gearboxes regardless of M40 or M41 are the same bar the main shaft so very good donors to repair Overdrive boxes that have gearbox ware or issues so the moral of that fact is never throw a M40 away it could get you out of trouble one day I stock pile them to repair with or make hybrids .

Plus you can make a hybrid fully rebuilt on the same money you buy a junker to rebuild from an outlet I know one of my customers Paid £900 for a junker to rebuild ( so paid for the gearbox to then pay out on top for a full gearbox rebuild and Overdrive refurb !!! ) he was extremely lucky that it ran after some work needed on the solenoid en me swearing for the right output shaft that was removed ....

Kind regards
Robert.w

[Volvorama]

I understand that a 'true' M41 has the oil filler/level plug at a different height on the gearbox casing (higher up?). It doesn't seem to make much difference, however, as I also had a hybrid gearbox and everything worked fine.

[jamie]

I wonder if the higher level plug of the M41 is for a good reason rather than random. Would this allow the oil to flow into the overdrive more easily as the gb will be fuller to a higher level??

[Ron Kwas]

Jamie;

I would agree on both counts...that Gearbox probably started life as an M40, and was turned into an M41 in order to accept an OD...and that the higher Filler Plug on the M41s in general is in order to raise the level, also for the sake of the OD.

Cheers