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M46 = m47 driveshaft?

Patdon10

New member
Joined
Oct 29, 2007
Location
Fairfax, Virginia
I have an AWful70 installed in my car, and I plan on converting to an M47.

I was going to try to find the front half of the drive shaft from a 240, but if I can't find one, can I pull one that has an m46?
 
I think the answer is no, but I'll let someone else tell you for sure.

Edit: not even all of the 240's with M46's have front half driveshafts that are compatible with other 240's with M46's, so for at least some 240s the answer is definitely no.
 
I have an AWful70 installed in my car, and I plan on converting to an M47.

I was going to try to find the front half of the drive shaft from a 240, but if I can't find one, can I pull one that has an m46?

I think the front half of the d/s may be shorter for the M46 due to the overdrive (5th gear) box. The 47 does away with the latter part of the o/d and incorporates 5 true gears.

To be safe just find a complete donor car with all the parts you need and you will have the correct d/s.
 
The M47s I've pulled out of 240s have all had guibos between the tranny and the driveshaft, whereas every M46 I've pulled has been a direct bolt on deal.

You're probably going to need an M47 specific front half.
 
The M47s I've pulled out of 240s have all had guibos between the tranny and the driveshaft, whereas every M46 I've pulled has been a direct bolt on deal.

You're probably going to need an M47 specific front half.

later m46's have guibos as well, like 1985+ or something, well at least on 740's... either way the front part of the driveshaft is diff than the m46 and the shifter cage is different.
 
You could get by with only getting the front section for the M47 driveshaft. But it would be more ideal if you got the complete M47 driveshaft. That's because the rear half of an M46 and the automatic driveshaft has a rubber insert and is a pressed together back half section. The back half of an M47 driveshaft is solid with the rubber guibo joint up by the transmission doing the job of absorbing driveline shock.
 
is this because of a length issue or a yoke issue?

The flange was the problem, not only was the bolt pattern different but the flange wasn't the right thickness, which made the driveshaft the wrong length. We ended up putting a different flange on the transmission to fit the driveshaft.
 
later m46's have guibos as well, like 1985+ or something, well at least on 740's... either way the front part of the driveshaft is diff than the m46 and the shifter cage is different.

No guibos on 240 M46s, even 86 cars, interestingly.

Interestingly, 84-86 740/760 with J-type overdrive have a plug and the speedo gear already installed in the tailhousing. You can remove the plug and install the speedo cable fitting/worm gear from a 240, but 86 240s have no plug and an undrilled boss in the tailhousing for the cable speedo. Makes things interesting when putting an 86 240 M46 in a 78 car having to update the reverse and OD wiring and put a different tailhousing and gear on it. Managed to get the job done in 6 hours, but it was a bit of a learning experience and involved pressing a couple bearings and swapping a tailhousing. I knew about the reverse lamp change, circular flange diameter change for the small driveshaft, and 4th gear switch/shifter bracketry changes going in and knew that would add some time, but the undrilled boss for the speedo cable on a J-type OD was a new one.

You should get the whole driveshaft form an M47 240 for an M47 240 honestly. The parts and u-joints will match, you get the stronger 2.5" rear section on the late model cars, and it just fits. In a pinch, the large diameter rear half from an M46 car can be used and still use the same support bearing if you gotta ship one i guess.
 
Curious to know if I can use the back half of an aw70 driveshaft with the front half of an m47 driveshaft for my m47 swap. Will it cause any vibration issues or noises? Are they the same between both setups?

Old thread recycling.
 
I'm using the back half of an aw70 driveshaft with an m46 front shaft. No perceptible vibration difference for my mix-n-match. At least for M46 the rear shaft has the rubber damper, where the aw70 shaft didn't. I think for the m47 the giubo takes over that job. I would think they would work together but cannot confirm.
 
Curious to know if I can use the back half of an aw70 driveshaft with the front half of an m47 driveshaft for my m47 swap. Will it cause any vibration issues or noises? Are they the same between both setups?

Old thread recycling.
You can do it but won't know if you have vibrations till you install it. But it's much better to just get the 2 pieces.
 
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