Projects M40 Volvo gearbox conversion Model A

I have been following MarcusJ and his VOLVO M40 TRANSMISSION CONVERSION IN MODEL A thread and have started putting in the work on converting a M40 Volvo box into one of the chassis we have lying around. I thought I would put up step by step photos of what is happening so feel free to step in and offer advice.

An AA bell housing was located in the US and Volvo box sourced from a Volvo mechanics mate. Both parts were hard to track down here in Australia.

Cutting out the centre of the Volvo bell housing.

 

Machining and drilling bell housing to fit gearbox.

 

Funny, earlier this week someone commented in another thread that hot rodders don't give a damn about Volvos or their engines. I'm glad to learn that hot rodders DO give a damn about their gearboxes!

My daily driver is an Amazon with the M40 gearbox. It's a beautifully reliable tranny. The only warning I'd give you is that some of them wear the nitride coating off the layshaft where the needle bearings ride the shaft, and then they start to make noise. If your tranny starts to howl, and the howling is there in every gear except fourth, that's the trouble. It might be worth pulling your tranny apart while it's out of the car, just to have a look at that nitride coating. There's no better time to replace it than when it's on the bench anyway.

If you want to see a photo of what the layshaft looks like with the nitride coating worn off, you can see a photo in my thread here, and you can also learn that it's possible to install the speedometer drive gear into its housing backward. (A wise man learns from other people's mistakes, right?)

http://www.volvoforums.org.uk/showthread.php?t=203641

 

Noted, Thanks CowbowTed.

 

Great job on your conversion ,,thinking outside of the box ,,it's got to be a big improvement over the Model A transmission ,,I have done a 3 speed mustang trans conversion using a AA bellhousing ,,had to get it from West Australia to Victoria,,I adapted it to the the torque tube and have had a bit of a run with it and is nice and quiet and smooth to operate ,,yours should work well ,,

 

Can an A bell housing be made to work? Or is this strictly AA


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From what I understand the AA bell housing and the Volvo box combination is the same length as the A bell housing and A box. Most importantly is the main shaft length. The AA bell housing is shorter than an A bell housing and allows the Volvo main shaft to reach the pilot bearing.

 

very nice job, thanks

 

I like the solutions you gent in other parts of the world use to make things work.

 

working on the same thing.Had to figure most out myself as some of the other threads didn't go into much detail of how they made the change.Im using a AA bellhousing and the Volvo clutch and pressure plate.Still need to figure out what to use on the clutch fork.Dont bash my trans cross member as it only temporary till I get my x frame and 40 ford pedals fitted and mounted

 

With the clutch fork I used the A type but had to use a V8 thrust bearing mount ,,,

 

think my main hang up will be what to use for drive shaft and u joint coupler behind the Volvo trans.Im using an open drive and most have used torque tube to banjo rearend

 

looks like a great swap , for a model a maybe even a flathead ?, tell me what do you do for speedo ? maybe count the guide posts

 

I dig this kind of stuff!
Question though, why all the fuss about cutting the Volvo bell housing?
Wouldn't it have been just as good and easier to cut a new ring?
Am I missing something?

 

I have to chuckle as I look at that photo of the back of the M40 tranny. How many Model As have reverse lights?

 

thats what i did just machined a piece of heavy wall tube to fit

 

The register diameter on the m40 is smaller than the AA bell housing by about an 1/8 per side. Need to fill the gap.


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Either Henry is rolling in his grave or he thinks this is pretty cool! Not sure which... but I'm impressed.


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It was pretty quick to chop out the centre of the bell housing but the main reason was I had no appropriate stock lying about to make a ring. I'm going to use an open drive as well unless RatFink can produce some more clam shell adaptors and rear shafts for the back of the Volvo box. Burl, do you have a part number for the clutch and pressure plate? I was going to use a Falcon clutch plate that I have that fits the Volvo shaft but it turns out the springs on the clutch hit the fly wheel bolts.

 

Not sure of the dimensions, but have a look at a Ford 8.8 rear end companion flange. They come in car (smaller) and truck (larger) sizes.

You might be able to drill and tap your flange to suit a yoke that fits one of those.

 

used the stock Volvo clutch assembly purchased at rock auto

 

Couple of other issues you will come up against.You will need to decide to use the ford pilot bushing and make a bushing to fit the different diameters or the stock Volvo and bush the flywheel to fit.I haven't decided on how to deal with the throw out bearing and clutch fork issue yet.Need to shorten the front of the output shaft around 8mm.Hope im not highjacking your thread just hoping to save you some time on figuring this stuff out.

 

throw out bearing and clutch fork differances

 

Had some time this morning so knocked up my version of the thrust bearing throw out and a bush to take the Volvo main shaft to the standard Model A pilot bearing. I haven't pressed the thrust bearing onto the throw out yet as I don't have a clutch and pressure plate yet and may need to machine it more. Again I didn't have stock big enough so I welded the ears onto the body of the throw out. The main shaft bush is only .97 mm wall thickness and I knocked it on to the shaft with a aluminium drift.

 

I forgot that the other day 8mm had to be cut of the end of the main shaft to prevent the end of the main shaft hitting the end of the crank and enabling the bell housing to bolt up properly.

 

By all means, hijack away. It seem we are at a pretty similar stage and I am interested in how you are going about the same problems.

 

Seems like a lot of work to go to and end up with a transmission that is a bit weak and parts are really expensive to obtain.

I have a 1930 A phaeton and decided to replace the 3 speed. I used a new Ford ranger 4 speed transmission. You can order gears to match the original model a 3 speed ratios and then for 4th I chose a gear that gave me approx. 24% overdrive.

I used a newer Mustang clutch assembly that bolted to the model A flywheel. I was able to use the original model a shift lever for the original look, it fits right into the Ranger shift tower. I had to shorten the drive line and modify the floor board as the shift tower was back about 3 inches.

I made a simple aluminum adapter from the A bell housing to the Ranger transmission.

I ended up with a 4 speed full syncro transmission 23%overdive in 4th. At 55 mph, my engine is turning rpms 37 mph with the original A transmission.

Cheap and easy and in my opinion a much better transmission that the Volvo and the added luxury of a simple overdive.

just sayin'

brasscarguy

 

Why would you match the Model A ratios? They half of the reason for changing to another box.

 

back in the 80's i mated a volvo box to a datsun 240z motor for a 38 chevy driver. the results were a great car, good power and mpg, looked stock on the outside. my precision method for the mating was to clamp a saws-all in the vice, and shim up the bells on the bench with plywood to the desired hight, and rotate the bell to cut. a studebaker disck was used which matched the datsun pp and volvo shaft, the for the next precision fab work i hauled the frame with motor installed to a friend who could tig aluminum, and with the datsun half on the motor, and the volvo half on the trans, i plugged the trans into the clutch hub and wiggled it around until we both thought it looked centerd, and he welded it up! i drove that car all over the country, out to the salt flats about 8 times thru the 80's. many trips thru the mountains convinced me i wanted more gears, so i put in a later volvo with overdrive. the long shift tower on these can be switched with the short shift tower, and then i wired the od solenoid so it could be controled by me and used to split gears and have 8 speeds forward. never use od in reverse. well it was a good idea, but i never got it to work. bad od solenoid i think, but too dumb to fix it. the car was replaced with different toys and just rested in the barn for 20 years, now sold to a friend who will make it smile again. long story just to say i like the volvo box!

 

witch flywheel are you guys using?