I have read there are few differences between these transmissions with the exception of the M47 being a true 5 speed transmission instead of having an overdrive unit. Has anyone put an M47 in place of an M46+J type overdrive? If you have or have any information that could be useful please let me know. I am curious to know if the output shaft flange is in the same location for the driveline connection or if there are modifications needed.
Icelos

Depending on the year of manufacture of the M46 that you are familiar with, the M47 transplant candidate may have a taller first gear. The aluminum cased M46 (starting with the 1982 model year IIRC) has the same ratios for 1st-4th as the M47, but the 5th gear ratio is just a bit shorter than the M46 OD ratio. Result is more usable power in 5th with less need to "downshift" into 4th gear at speed.

In addition to being "longer" than the M47, the M46 sports a drive gear for speedo cable and the M47 does not as post '86 models have an electronic speedometer with a sending unit on the rear axle.

The M46 is said to be a more robust gearbox and is not afflicted with the lubrication issues that plague many M47s. Why are you considering this particular swap?

I kinda new to tranny swaps but I think you will need to change the drivshaft, crossmember and shifter.
--
1990 240 Sdn 277K,tach,strut brace,turbo sway 1990 240 Wgn M47II 157K,tach,strut brace,poly bushings,IPD sways

Still looking for more responses. Responders check your e-mail. Thanks.

I have swapped the other way...M46 in the place of the M47. Had to also replace the driveshaft (of course) and run the wiring for the overdrive. We have had problems with the M47 in Florida...don't know why. We have also had problems with the M46, but these were always owner error, "I always wanted to work on one of these" related...ie 90WT instead of Type F. We've also had a shocking lack of ability to find an M47 close enough to ship affordably when one craps out. The past three that have died have been converted to whatever transmission and driveshaft a recent teenager accident provided us with.

I have never done it but I can tell you from experience that the M47II is a shorter box overall. It has an extra case scabbed onto the back of it that makes it about 8" or so longer whereas the O.D. unit on the M46 has to be at least 12" long with the intermediate housing that it uses. When the M47II first came out the word from the Swedes was that you were not going to see it put on any B230FT motors because the max horsepower that it was rated for was right at what the FT would put out. They felt that the prospects of it's overall longevity was not good so they stuck with the beefier M46 on the turbos. They said that there was an earlier version simply called the M47 that was introduced in Europe at that it made so damn much noise that it never made the trip over. They redesigned it, changed a couple of gears around, and called it the M47II and that is the model that we see in the states. I do not see a great deal of them in the market I work in (So. Cal), but I have had no problems with the ones I have seen. I think that the case on them is aluminum too, I know that the extra case in the rear is for sure.

I had an 87 245 with an M47, and it had well over 250k miles on it when I sold it. I used it for towing loaded tow dollies 1000 miles at a time, and it handled the stress well.

The biggest problem with swapping one into a pre-86 240 would be the lack of a mechanical speedometer drive. They were made for cars with electronic speedometers.
--
1991 245, 61k miles, looking for a 5 speed 92-93 245 cheap.