M5OD-HD main shaft swap

[turbo91xlt]

Any confirm I can take the main shaft out of a 4.0 m5od-hd and replace it with one from an older non HD trans? Reason is the older 4wd tail housing extension with the manual t-case shifter bosses does not fit on the m5od HD due to the OSS reluctor thats in the trans. Since I am putting this trans in my '91 STX I dont need the OSS sensor.

 

[BlackBII]

The HD has an extra bolt hole on the bell housing, and apparently a different first and second gear. From what I've read the internals will swap just fine, though if the gears are different it would mean swapping the counter shaft as well.

It seems easier to just make a mount for the shift linkage though, as seen at the very end of this article

How to replace a M5OD-R1 with a M5OD-R1HD

therangerstation.com

 

[turbo91xlt]

I found today an '88 B2 in my local yard with 110k miles on it with an m5od so I think Im just gonna buy that & slap it in my STX. The lower transmission ratios plus 4.10 gears should give that ol' 4.0 ohv some decent low end grunt haha.

 

[turbo91xlt]

Saves me from having to using one of my rare FX4 Lvl II tail housing extension on a truck that doesnt use the OSS sensor.

 

[turbo91xlt]

For those that wonder why the older tail extension doesnt fit the m5od-HD its because the rear output seal is located 1" further back in the housing for the OSS sensor reluctor wheel. The matching machined seal surface on the output shaft is also in a different spot hense the need to swap both the main shaft & extensions together.

 

[alwaysFlOoReD]

Thanks for the update.