Gearbox - 144

[142 Guy]

If what you want is closer ratios the M47 (or M46) is definitely not the answer. If you check the actual ratios (1-4 appear to be identical on the M46 and M47) the 1-2 and 2-3 shifts are all farther apart on the M46/M47 than they are on the M40. The M46 and M47 come with a very short first gear 4.03:1 (the M40 is 3.13) so those cars must have had a very tall rear end.

The Getrag M51 used on the Volvo 264 was a 5 speed with a 1.00:1 ratio on 5th; but, has a first gear similar to the M46 which would be suitable for pulling a plow in the field with your 4.56 rear end. If you change your rear end the M51 ratios from the 260 might work better; but, when you look at the 1-2 and 2-3 spreads they are not closer than an M40. The M51 might be pretty rare because every 260 series that I have ever seen on this side of the Atlantic had a slush box. The M51 would definitely not be a drop in fit. The Volvo GPA 240 cars used an M51 with very tight ratios; but, with a very tall 1st gear - which might work with your 4.56 final drive. Good luck trying to find one of those!

I don't know what T9 variant your Seven has; but, the ratio spreads in the T9s that were in the XR4ti / Sierra appear to be more like the M46/47. It is an OD 5th, 1:1 4th so not an inherent close ratio box. There are different 4 cyl versions; but, they all appear to have a wider spread between 1st and 2nd than the M40. Some have a 2-3 spread that is close to the M40.

Reality is that compared to most other transmissions, unless you are prepared to try customized gearsets you are going to have a tough time finding another transmission with closer 1-2 and 2-3 ratio spreads than the M40. Here are some resources with transmission ratios that will demonstrate how hard it is going to be to find a closer ratio gear set than the M40.

https://people.physics.anu.edu.au/~a...s_compared.htm

http://www.nuceng.ca/bill/volvo/database/tranny.htm

[Underdrive]

Bearing in mind what others have said about the gear ratios of alternative 'boxes how about approaching it from a different angle. Look at creating a broader torque curve at the appropriate areas of the rev range, by changing and timing curves camshaft.

[142 Guy]

Originally Posted by Underdrive

Bearing in mind what others have said about the gear ratios of alternative 'boxes how about approaching it from a different angle. Look at creating a broader torque curve at the appropriate areas of the rev range, by changing and timing curves camshaft.

I was thinking the same thing. It would probably be easier than a transmission retrofit.

Another option to consider is fitting the short shifter from the later 140 or 1800 if your pre 1972 140 still has the long shifter. With the shorter throw it will speed up shifts and reduce the vehicle speed drop during shifts which will keep the engine operating closer to its torque peak. Not a drop in fit; but, more drop in than trying to fit a true close ratio 5 speed (if you can find one).

[142 Guy]

Originally Posted by rm0rgan

We were on a HERO rally this weekend our 144 (4 speed) and found the gear ratios way too long to keep it on the boil, especially up some of the steep hills and on some of the auto-tests.

Someone mentioned that the 240 5-speed gearbox will fit without any modifications needed - has anyone done this / know if this is correct?

Very grateful for any help. Photo for attention

Attachment 131114

I was looking more closely at your photo. It looks like the windshield squirters have been fitted to the hood. What a good idea because the 140 squirters mounted in the cowl are pretty much useless in terms of being able to aim them to spray the glass. Mine do an excellent job of spraying the wiper arm unless the wipers are running when you use the spray.

I don't know whether its just the photo; but, it looks like the vents in the cowl along the base of the front windshield have been sealed off. If that is not a photo illusion is that for strength or some other purpose?

[AndrewBrown]

All the info you will ever need regarding Volvo boxes

http://www.nuceng.ca/bill/volvo/database/tranny.htm

https://people.physics.anu.edu.au/%7...s_compared.htm

https://people.physics.anu.edu.au/%7...tech_index.htm

https://people.physics.anu.edu.au/%7..._volvo_240.htm

Andy

[AndrewBrown]

Originally Posted by 142 Guy

I was looking more closely at your photo. It looks like the windshield squirters have been fitted to the hood. What a good idea because the 140 squirters mounted in the cowl are pretty much useless in terms of being able to aim them to spray the glass. Mine do an excellent job of spraying the wiper arm unless the wipers are running when you use the spray.

I don't know whether its just the photo; but, it looks like the vents in the cowl along the base of the front windshield have been sealed off. If that is not a photo illusion is that for strength or some other purpose?

just my opinion....

I would keep the original ones and fit modern fan type spray ones from a modern car with twin pumps and have all 4 jets, you could even have a switch to allow you to enable or disable the extra jets if you wanted to,

also the bonnet jets in the photo look like rear wiper jets from an early 245 to me

[221Tom]

Originally Posted by Derek UK

4.10 in an Estate? Tell us more. I've run an M41 with a 4.10 in a Stromberg/twin down pipe B18a 4 door and liked it very much. It ran sweeter at 70-80 than my Estate with B18B/M41/4.56.

Hi Derek,

I’d agree it’s spot on for 70-80 driving , around 2500 rpm. Apparently, the previous owner spent a lot of time on French motorways, so converted a saloon axle and added overdrive. We spend most of the time on A and B roads, so the 4.56 works for us, with the overdrive taking the edge of things.