It's possible I may if mine doesn't come right after a service.
Volvo 145 1974 Build thread
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Tell me something. I've been reading about m40's and m41's today. The 4th gear on the m40 is the same 1:1 ratio as 3rd on the bog warmer is it not? ..so our B20s will still scream at highway speeds then with a m40?
So the only simple solution to get overdrive is what?
M41's seem ridiculously hard to find and of you do then they are expensive.
Can you buy one of those laycock overdrive units and bolt em up to the m40?
So the only simple solution to get overdrive is what?
M41's seem ridiculously hard to find and of you do then they are expensive.
Can you buy one of those laycock overdrive units and bolt em up to the m40?
Change the diff ratio at the same time is the general plan.
If you have a dead one, please consider donating it to @Vee_Que for AW-71 adapter ring measurement purposes
Final drive bw35 would be roughly the same as m40. So similar screaming at highway speeds either way.
Could get m41, could get a slower differential. Fun option would be m41 and drop in a 4.56:1.
M40 is cheaper and I have big '74 model driveshaft to suit m40 already.
Other thing about m41 is you also need one with a 'remote' style gear shift, so an early 140 or 120 with bus style shift won't cut the mustard.
My understanding is there are physical differences between m40 and m41 that facilitate the overdrive fluid passages and such. Others may be able to correct me.
Could get m41, could get a slower differential. Fun option would be m41 and drop in a 4.56:1.
M40 is cheaper and I have big '74 model driveshaft to suit m40 already.
Other thing about m41 is you also need one with a 'remote' style gear shift, so an early 140 or 120 with bus style shift won't cut the mustard.
My understanding is there are physical differences between m40 and m41 that facilitate the overdrive fluid passages and such. Others may be able to correct me.
In theory, yes; in practice, no, because you need the M41's longer drive shaft too. Also, the M41's main gear case is slightly different to the M40's.bigal;104175 wrote Can you buy one of those laycock overdrive units and bolt em up to the m40?
Easiest solution today for a 5 speed is to get a T5 adapter plate from @Vee_Que, and raid your local wreckers for an EB Falcon T5 gearbox. You can still get replacement synchos and gears for T5s without mortgaging the children. M45 / M46 / M47 synchros are now 'Extinct' as a species, and replacement gears mostly so.
The shift lever extension cover (AKA remote style gear shift) will swap over from M40 to M41.Essbos;104179 wroteOther thing about m41 is you also need one with a 'remote' style gear shift, so an early 140 or 120 with bus style shift won't cut the mustard.
My understanding is there are physical differences between m40 and m41 that facilitate the overdrive fluid passages and such. Others may be able to correct me.
You are correct about the main case differences from M40 to M41, for the precise reason you stated.
Thanks.. starting to understand all the options and variations now.
Also need to swap output flange to fit later model drive shaft, cable operated clutch fork if ex-120, and j-type overdrive would be desirable?bgpzfm142;104181 wrote
The shift lever extension cover (AKA remote style gear shift) will swap over from M40 to M41.
Are there any fancy overdrive devices that can be used in conjunction with the bw35?
Probably 3.73:1 differential from a 144 gl
http://www.gearvendors.com/restorationclassic.html
Gearvendors OD unit would be adaptable but cost is in the thousands.
Gearvendors OD unit would be adaptable but cost is in the thousands.
Ummmm... that's a good point, actually, about the flange. B20E cars usually came with the bigger, stronger tailshaft using the 1310-type fittings. And, yes; a J-type Laycock, since even a stock B20E would soon make mincemeat out of a D-type.Essbos;104183 wroteAlso need to swap output flange to fit later model drive shaft, cable operated clutch fork if ex-120, and j-type overdrive would be desirable?bgpzfm142;104181 wrote
The shift lever extension cover (AKA remote style gear shift) will swap over from M40 to M41.
140s did come standard with a cable clutch, but you could do a hydraulic system if you're feeling enterprising and don't enjoy the sudden surprise of another broken clutch cable when you're midway in a downshift for a rapid right-hand turn in traffic.
I can confirm that an m41 with 4.56 and B20e is an excellent combination to drive. I have looked over the M40 to m41 conversion option by having both sets of parts on the bench in from of me. It is possible, but the main shaft, extension housing and overdrive unit seem to end up the same price as shipping a complete box from the USA. But technically it can be done, I have fitted up the parts. Also they can also have clutch cable also. My 144 GL has cable, definitely factory, and this always struck me as odd for such a car.
7 days later
164s got 'em, but 140s never not 3.73s standard AFAIK, only 4.1:1 and 4.3:1. Everything else was optional.Essbos;104185 wroteProbably 3.73:1 differential from a 144 gl
The front tailshaft is different of course, but the M40 and M41 gearbox crossmembers are also slightly different.1971_144GL;104200 wrote I have looked over the M40 to m41 conversion option by having both sets of parts on the bench in from of me.
My 3.73 and 4.56 out of a 144(74 model with b20e+BW35) and 142(67 model with B18b+m41) must have been options.bgpzfm142;104764 wrote
164s got 'em, but 140s never not 3.73s standard AFAIK, only 4.1:1 and 4.3:1. Everything else was optional.
Interesting! That was either a special order, or somebody put a 164 diff in it. Does your car have any Special numbers on the ID plate which are different to this?Essbos;104817 wrote
My 3.73 and 4.56 out of a 144(74 model with b20e+BW35) and 142(67 model with B18b+m41) must have been options.
(This plate is on my 1974 145, with B20E and BW35. The book doesn't list whatever special options S-6168, S-6261, S-6263, or S-6265 actually are, so any info on them is welcome).
The book says that in a 74 model, you either got a 3.9:1, a 4.1:1, or a 4.3:1 from the factory.
See parts book, Grupp 4, page 76.
http://weblisher.textalk.se/gcp/20160126-006/paper.pdf
You're right to pull me up, the B18 car is a different story, my statement was somewhat overbroad and should have been "73 and 74 model 140s in Australia never got 3.73s as standard AFAIK, only 4.1:1 and 4.3:1".
The other option for a box is a Celica steel case box.
Honestly, revving at 3500 at 100kmh is where the engine likes it. Sure it's not life a modern car that goes to 2000rpm in top, but it's not that big a deal either. Keep in mind the bw35 will rev higher also because of torque converter losses.
Honestly, revving at 3500 at 100kmh is where the engine likes it. Sure it's not life a modern car that goes to 2000rpm in top, but it's not that big a deal either. Keep in mind the bw35 will rev higher also because of torque converter losses.
6 months later
How's the 74 145 going? (the best model on the planet btw).
