New member here.
I’m on my 4th Swede. 1st, a 66 122, then a 94 855T, followed by a 67 122 wagon that I restored and my daughter drove to high school (sold on BAT in 2017) and I picked up from BAT a survivor 73 142 (YELLOW!) in Portland with bit over 200K miles last summer.
The 142 has the dreaded BW3 automatic that I dislike immensely!
I would like to start the process of converting it to 4speed with overdrive OR a true 5 speed.
Has anyone here know how I might get started on this. I’m a ferry ride away from X-Ray automotive and hear they might be a place to possibly procure all the pieces to pull this off. Also I do not have a lift at my house and wonder if it is possible to do this exchange w/o pulling the engine…
Thanks for any responses.
David
BW3 Automatic to M41 swap on a 142
-
foggydogg
- Posts: 2948
- Joined: 17 October 2009
- Year and Model: '98 V70 R, 97 850 T5
- Location: District Of Columbia, not one of the Several States
- Has thanked: 83 times
- Been thanked: 402 times
Since it shares lineage with the Amazon - and it came both ways from Mother - it should be fairly straightforward, aside from the fact it's 52, and wasn't produced in the same numbers. I did both an 1800 and 122 swap; no need to pull the engine, but it has to be high enough for comfortable maneuvering under. Finding a complete donor would be ideal, but see '52', above. Pedals might be harder to source than a transmission. If you intend to include O/D you'll need switchgear and the relay setup.
69 1800s, @500k Death by Rust
94 850 Turbo, T-boned, ambulance for me, crusher for it
97 855 T5, 855 R projects
98 V70R x2, Silver Junkyard rescue, Coral Red
98 V70GLT x2, parts cars
00 V70xc x2, both now dead
62 122s, gone to live in Richmond
56 445 Duett basket project
1950 Studebaker 2R10 flatbed, T9 crashbox
94 850 Turbo, T-boned, ambulance for me, crusher for it
97 855 T5, 855 R projects
98 V70R x2, Silver Junkyard rescue, Coral Red
98 V70GLT x2, parts cars
00 V70xc x2, both now dead
62 122s, gone to live in Richmond
56 445 Duett basket project
1950 Studebaker 2R10 flatbed, T9 crashbox
-
BlackBart
- Posts: 6492
- Joined: 10 December 2016
- Year and Model: 2004 XC70 BlackBetty
- Location: Over the far far mountains
- Has thanked: 927 times
- Been thanked: 884 times
Nice to see a real Old Volvo thread in here.
Foggy knows his stuff. X-Ray is a smart shop. If you swap it with engine in, a rental transmission jack may save your butt, and your back, and maybe your ribs.
Foggy knows his stuff. X-Ray is a smart shop. If you swap it with engine in, a rental transmission jack may save your butt, and your back, and maybe your ribs.
ex-1984 245T wagon
1994 850T5 wagon
2004 XC70 wagon BlackBetty
1994 850T5 wagon
2004 XC70 wagon BlackBetty
-
chrism
- Posts: 1307
- Joined: 28 January 2009
- Year and Model: S80 / 2005
- Location: Atlanta, GA
- Has thanked: 7 times
- Been thanked: 78 times
I did a BW35-to-M41 swap in my ‘73 1800. The car is not completely road worthy so I haven’t had it out of the neighborhood or above 3rd gear. When you did your conversions did you include a 4.56 diff or did you stick with the 4.10? If still running the 4.10, I’m wondering what it was like to drive. Too tall? I have a 4.56 laying in the garage (condition unknown) but the original 4.10 is still in the car.
Ditto on finding a 142/144/145 donor car would be nice. I found an 1800 donor for my project and I’m glad I did!! There seems to be no end to the bits and pieces needed to do a “proper” (or thorough) conversion - ie: front driveshaft, different crissmember mount, indicator light, wire harness…. Etc.
-
122sPhil
- Posts: 43
- Joined: 21 September 2025
- Year and Model: 1966 122
- Location: Vancouver BC
- Has thanked: 1 time
- Been thanked: 2 times
I just bought a 122 with the auto trans
I’ll see how it is, maybe it’s actually comfortable for city driving ?
Auto trans was a more expensive option and tgey seem a little rare especially nowadays
I did convert my 122 I bored to 2l balanced C cam polished ports etc
I installed the OD trans
It was geared too high Unless you live on the prsries and want yo drive at astronomical speeds and have no hills
Don’t forget you’ll need to shorted and balance the driveshaft if you don’t get that and the column switch is nice to have too
Between 66 and 67 there seemed to be a different support bearing rubber hanger thing
I had to fool around with the height and had the driveshaft balanced
Dropping the rear axle gearing helped lots also I replaced all the bearings It reduced slop and tgat made driving at about 4 MPH a lot more comfortable
Don’t hook it up so the OD works in just any gear , I have a busted in half one from someone who did that
I’ll see how it is, maybe it’s actually comfortable for city driving ?
Auto trans was a more expensive option and tgey seem a little rare especially nowadays
I did convert my 122 I bored to 2l balanced C cam polished ports etc
I installed the OD trans
It was geared too high Unless you live on the prsries and want yo drive at astronomical speeds and have no hills
Don’t forget you’ll need to shorted and balance the driveshaft if you don’t get that and the column switch is nice to have too
Between 66 and 67 there seemed to be a different support bearing rubber hanger thing
I had to fool around with the height and had the driveshaft balanced
Dropping the rear axle gearing helped lots also I replaced all the bearings It reduced slop and tgat made driving at about 4 MPH a lot more comfortable
Don’t hook it up so the OD works in just any gear , I have a busted in half one from someone who did that
-
122sPhil
- Posts: 43
- Joined: 21 September 2025
- Year and Model: 1966 122
- Location: Vancouver BC
- Has thanked: 1 time
- Been thanked: 2 times
le me know if youneed pedals, I have a coupleo f scrap cars Iol be gettin grid of soon. I plan to save a set in case I do the same swap later down the road.
Im sure you will wan thte clutch master,and slave cylinder. it might be a cable in later versions. my new to me 122 wiht the borg warner 3 speed just has a factory plug where the clutch master cyl could have been.
since there are two different driveshaft support bearings used I'd look for the later version if you can.. but either could likely be made to work. my 66 had small rubber hanger things, my 67 had a larger rubber thing that sits up against the underside of the hump for the floor to clear the driveshaft. I used the later oen and added or removed some rubber shims until I was happy with the height. if the height or balance is not right it will vibrate at higher road speeds. the axle speed is determined by road speed it has nothing to do with what gear you are in.
the solenoid can fail it has two windings , one to pull it in the other holds it in.
before you befgin I'd make sure your soilenoid is ok, it may be somewhat rare.
I believe the oil used is different despite the fact that the rest of the trans is similar.
this one I just got is very original so Il try it, I dont know what to expect fro the thing. it had sat a long time but has very low mileage , only 65K (miles) I though I might actually like it for city driving. You'll enjoy the upgrade im sure.
if you can go to tthe cable clutch then you wont need the reservoir and the slave cylinders often do leak. Im a firm believer in converting them to silicone ( dot 5 fluid)
silicone wont absorb water like brake fluid does and the clutch does not have boiling issues. I converted both brakes and clutch.. If you only do one you have to be very careful not to get mixed up because the fluids are not compatible. when I did the changeover I replaced everything.
silicone is often frowned upon becaue it boils easier than dot 3 or 4 so it isnt; for racing or hard driving, however , after 2 years the brake fluid will absorb water and then it will boil at a lower temp than the silicone will.
becaue I use my car for short period and it is often stored I opted for the silicone so then I wont have rusty brake parts. it seemed to make the clutch cylinders last way longer.
if you look at the clutch cylinder, well it is of course a linear motion, the clutch fork however moves in an arc, not a linear motion , I believe this causes the slave cylinder to side load. maybe theats why seals don't last so well in those? it may have only been in 69 that a cable was used, the parts may be a bit rare.
in a 123 GT or a 122 wagon with OD it had a special switch that looks similar to your signal light switch, but opposite it on the column.
some later volvos used a pushbutton and a relay so you could adapt that way if you put it somewhere else .
you can shift the OD in and out , without the clutch I always use my clutch anyway, to reduce wear on the OD clutch assy.
if you dont have a shortened driveshaft you can have one shortened, I believe only the section near the engine is different.
maybe you can fool around with wheel sizes , maybe easier than a rear axle swap but then it wont look OEM either.
Im sure you will wan thte clutch master,and slave cylinder. it might be a cable in later versions. my new to me 122 wiht the borg warner 3 speed just has a factory plug where the clutch master cyl could have been.
since there are two different driveshaft support bearings used I'd look for the later version if you can.. but either could likely be made to work. my 66 had small rubber hanger things, my 67 had a larger rubber thing that sits up against the underside of the hump for the floor to clear the driveshaft. I used the later oen and added or removed some rubber shims until I was happy with the height. if the height or balance is not right it will vibrate at higher road speeds. the axle speed is determined by road speed it has nothing to do with what gear you are in.
the solenoid can fail it has two windings , one to pull it in the other holds it in.
before you befgin I'd make sure your soilenoid is ok, it may be somewhat rare.
I believe the oil used is different despite the fact that the rest of the trans is similar.
this one I just got is very original so Il try it, I dont know what to expect fro the thing. it had sat a long time but has very low mileage , only 65K (miles) I though I might actually like it for city driving. You'll enjoy the upgrade im sure.
if you can go to tthe cable clutch then you wont need the reservoir and the slave cylinders often do leak. Im a firm believer in converting them to silicone ( dot 5 fluid)
silicone wont absorb water like brake fluid does and the clutch does not have boiling issues. I converted both brakes and clutch.. If you only do one you have to be very careful not to get mixed up because the fluids are not compatible. when I did the changeover I replaced everything.
silicone is often frowned upon becaue it boils easier than dot 3 or 4 so it isnt; for racing or hard driving, however , after 2 years the brake fluid will absorb water and then it will boil at a lower temp than the silicone will.
becaue I use my car for short period and it is often stored I opted for the silicone so then I wont have rusty brake parts. it seemed to make the clutch cylinders last way longer.
if you look at the clutch cylinder, well it is of course a linear motion, the clutch fork however moves in an arc, not a linear motion , I believe this causes the slave cylinder to side load. maybe theats why seals don't last so well in those? it may have only been in 69 that a cable was used, the parts may be a bit rare.
in a 123 GT or a 122 wagon with OD it had a special switch that looks similar to your signal light switch, but opposite it on the column.
some later volvos used a pushbutton and a relay so you could adapt that way if you put it somewhere else .
you can shift the OD in and out , without the clutch I always use my clutch anyway, to reduce wear on the OD clutch assy.
if you dont have a shortened driveshaft you can have one shortened, I believe only the section near the engine is different.
maybe you can fool around with wheel sizes , maybe easier than a rear axle swap but then it wont look OEM either.
-
122sPhil
- Posts: 43
- Joined: 21 September 2025
- Year and Model: 1966 122
- Location: Vancouver BC
- Has thanked: 1 time
- Been thanked: 2 times
I went and retrieved an engine with clutch assembly and spare pedals thanks for reminding me Ill need that. my plan is to try the auto trans, and then maybe later find an M41 but I have a 4 speed. the M41 is a bit harder to find, as I understand it the main difference is that the output shaft is larger , so dont buy an Overdrive thinking it can just hang off the back of a standard 4 speed, you need that longer shaft as well, from what Ive heard the rest is about the same.. the one in my 122 with overdrive is a bit noisy so I considerd trying tot use parts from a manual maybe change all the bearings, it works fine for now.
youll of course need the clutch plate and I dont know anbout balance, really best if the crank and pressure plate can be balanced as a unit and you can consider lightening it
what I did was hopped up the engine but left the flywheel heavy, fun to gear down and sling it back into a lower gear coming out of corners and get that little push ahead. I dont really care about losing the first bit of accelleration, it would be quicker off the line wiht the light flywheel, no difference in actual power. Its a decision you might make for yourself
when I did mine I sent the crank rods , pistons, all the rotating parts , and had them balanced, I think that was very worthwhile. even the new pistons came back with a bit removed. I bored from 1800 to a standard 2 litre, It says somethign about the block being able to bore a B18 that far. sturdy little things they are.
youll of course need the clutch plate and I dont know anbout balance, really best if the crank and pressure plate can be balanced as a unit and you can consider lightening it
what I did was hopped up the engine but left the flywheel heavy, fun to gear down and sling it back into a lower gear coming out of corners and get that little push ahead. I dont really care about losing the first bit of accelleration, it would be quicker off the line wiht the light flywheel, no difference in actual power. Its a decision you might make for yourself
when I did mine I sent the crank rods , pistons, all the rotating parts , and had them balanced, I think that was very worthwhile. even the new pistons came back with a bit removed. I bored from 1800 to a standard 2 litre, It says somethign about the block being able to bore a B18 that far. sturdy little things they are.
-
- Similar Topics
- Replies
- Views
- Last post