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M5OD vs FM145


abunchofidiots

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I keep reading that the M5OD is vastly stronger than the FM145/FM146. What parts inside make it so much more desirable and stronger?
 


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Captain Ledd

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It's an entirely different transmission.

better alloys, heavier duty bearings, stiffer case, larger internal parts all around.

It's a newer, better design overall. It's not really a case of one single improvement.
 

Beanmachine7000

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Does it really matter what makes it stronger? As long as it is, lol...
 

Original_Ranger84

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There was essentially 3 manual transmissions put into the rangers. The Mazda Toyo Koygo, Mitsubishi FM 145/46, and the Mazda M5OD.

Both the mazda transmissions are stonger then the Mitsubishi and the M5OD is the most desired. None of the parts interchange between the different ones. Although if you have 2.3L or a 3.0L with the M5OD and you can get your hands on a 4.0L M5OD then you can swap out the internal gearing and get a lower 1st second and 3rd gear.
 

4x4junkie

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Bigger gears, better lubrication, and the biggest one of all, tapered roller bearings are what set the M5OD apart from the others.
The most common failure points with the Mitsubishi transmissions are the input shaft BALL bearing (which takes the rest of the trans with it), and wasted 5th gears from poor lubrication. Almost any RBV with a Mitsubishi that's parked because of tranny problems I would bet $$$ it's for one of those two reasons.

The M5OD on the other hand... All I really ever see killing them is an owner neglecting to fix a leak (or at least making sure it stays full of fluid). The three small rubber shift-rail plugs on the rear of the shifter housing are known to leak after they've aged some. There's some info in the Tech Library on replacing them with metal plugs.

Although if you have 2.3L or a 3.0L with the M5OD and you can get your hands on a 4.0L M5OD then you can swap out the internal gearing and get a lower 1st second and 3rd gear.
It's the other way 'round... If you have a 4.0L, you can get lower (wider ratio) gears by swapping internals from a 2.3 or 3.0L one into your 4.0L case.
 
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Original_Ranger84

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It's the other way 'round... If you have a 4.0L, you can get lower (wider ratio) gears by swapping internals from a 2.3 or 3.0L one into your 4.0L case.
I think the tech library needs to be updated then. Wait nevermind I keep forgetting to put the to one ratio on those things. :icon_twisted:
 

kenwheeler

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My FM 146 crapped out. Went to the junkyard and found another one easy enough. I think I'm going to have the first one rebuilt in anticipation of the new FM 146 crapping out.
 

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Your FM146 is a direct swap for the M5OD-R1. Instead of rebuilding the spare, buy a used Mazda trans to have available.
 


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