Hi all,

I'm doing an auto to manual swap on my 1987 740. I have a donor gearbox from a 240. I am aware the shifter is slightly shorter on a 240, but i've got the cage and linkage from a 740 M47, so it will fit nicely once i put it on.

I'm finding it very hard to find a tailshaft from an M47 740 car here in Australia, as the 240 tailshaft will not fit. I've come to a conclusion that i better get a custom made tailshaft as its just too hard to find a stock one.

What do the tailshaft makers need to know to fabricate one? I've got no measurements of an M47 740 tailshaft and i can't find any pictures of it.

Could anyone suggest what the makers need to know to fabricate one?

Any help would be greatly appreciated.

 

if you measure the distance from the transmission shaft mounting flange to the differential shaft mount (with the car sitting on its wheels), and give them the back of the 740 automatic shaft, and the front of the 240 manual shaft, a driveshaft shop can probably fake it up.

 

Is there a way you can use the back portion of the driveshaft from a 240?

As far as i'm concerned, it is possible to get the front driveshaft section for the M47 gearbox and then use the rear section from a 240, according to some people.

I can get the front section, but no one in Australia seems to have the back section.

I'm not 100% sure if this will work. Any ideas?

 

iirc, the automatics have 3 u joints, front, center, and rear, while the manuals have a flexdisk aka guido in the front, with the same 2 mid&rear u joints. i do not know if the 740 diff has a different flange on it vs the 240. both cars have two piece driveshafts with a center spline that slides, and they both use a center shaft support bearing, with different bearing mounts

ideally bring the shaft shop the whole 240 manual shaft and the 740 whole shaft, along with the length measured from the car... they can cut it up and splice it together, then spin balance the new assembly.