M5OD 4x4 or 2x4 Trans ???

[1v6pony]

Is there a difference between the 4x4 and 2x4 M5od?? I need to replace mine and do not know if was origianly a 4x4 or 2x4 this is not in a ranger and has a custom tail shaft for a dana 300 T-case.. it is fitted to a 1995 3.0 motor

 

[CopyKat]

Tail shaft and tail housing are different.

However you can convert a 2wd trans to a 4x4 trans if you have the nessecary parts.

 

[1v6pony]

Can you tell me how to tell the difference.. As the tail shaft housing on mine is allready a custom piece not original what is different a bought the tail shaft?? is it the spline count or the length or other???

 

[CopyKat]

If you have a D300 T-case I can bet that inside the tailhousing is an adapter collar, changing the trans spline to the D300 spline.

The only way to really tell what it was originally is to remove the D300 case and visually see the length difference in the tail shaft.

End of a 4x4 tail shaft.

End of the 2wd tail shaft.

You can see thatt the 2wd output is quite a bit longer. Never checked to see what the total length difference is.

How long is your adapter housing? I really doubt that a 2wd output shaft was used otherwise your adapter length would be nearly 18" long.

 

[TireIron]

if yours is already custom then you should either look into getting any M5OD and swapping your custom tailshaft and tail housing into it or finding a different transmission to use that the dana 300 will bolt up to, or get a 4x4 M5OD and use a BW 1350 or 1354 t-case.

 

[1v6pony]

Well it looks like it is the 2 wheel drive version.... from the Transmission case where it bolts to the Tail shaft case the shat is apx 8.5 inches long does this sound like the 2x4 or the 4x4 version...

If mine is the 2x4 how difficult is it to excange the tail shaft from one to another... I just got a line of a 4x4 M5od for $100.00

The whole reason I am doing this is my case has a bad crack in it.

Thanks Guys
Brad

 

[CopyKat]

Sounds like the 4x4 version. The 2wd sticks out nearly a foot from the bolt flange on the trans.

I can take a couple of quick measurements when i get home. I've got a 2wd and 4x4 trans sitting on my shop floor.

 

[1v6pony]

Well I found out that the tail shaft is thicker on mine and thinner on the new one... It appears that the orig one is a 2 wheel drive that has been cut down to the 4wd length as the photo you sent of the 2wd has a check ball slot in the shaft and the 4wd does not... Also it was full of gear oil should I continue to use it or change it out????
It looks like I will be swaping things around, Do I need to remove the top cover to exchange the main shafts????

 

[AllanD]

Yes, you'll need to remove the top cover, both front and rear bearing retainers
(the rear one after disassembling reverse and 5th).

Final disassembly of the M5OD-R1:
after you have 5th and reverse on the bench.

stand the case on either end and just "jounce it around"
until the straight roller bearings for the countershaft fall off the
shaft and out of the case.

I do it this way because I'm 6'4" and 290lbs and I make it look like I'm shaking a martini (granted a BIG martini, but...)

when you have both roller bearings out you can put the transmission back on the bench because at this point the countershaft will drop down in it's bearing journals and that will allow you to lift the mainshaft up at both ends, rotate the "flats" on the input gear to the top and bottom, pull the input gear forward as you pull the mainshaft back at some point you will be able to tip the front end of the mainshaft UP and tip the input gear to one side and take it out through the front main bearing bore.

Next you tip the mainshaft up (at the front) and slightly towards the drivers side of the case and the mainshaft will slide out of the case.

honestly I do this so quickly that it has taken me several times
as long to type the last two paragraphs than it does to have the mainshaft sitting on the bench and be reaching for the cluster gear to remove it from the case.

In other words, the hard part is disassembling the "japanese puzzle" we call 5th and reverse in the sequence necissary.

*********************************************

Then again I've done it so many times it is as reflexive
as unzipping my pants to pee...

*********************************************
The four NEVERS (four things that people disassemble that they DO NOT need to and doing so only creates problems later)

These FOUR important things to know when disassembling
a mazda M5OD-R1:

1)NEVER remove the reverse idler gear from it's shaft.
Remove the 17mm bolt that holds the shaft to the case and
remove it as an assembly. (when re-installing it use the tailshaft
housing as an alignment guide when torquing the retaining bolt)

2)NEVER remove the rev-5th shift fork from it's shaft remove
the UNIQUE bolt that holds the shaft in the case and remove
the fork, shaft and internal detent as an assembly.

3)NEVER remove the big TORX nut from the rev-5th bellcrank pivot
Remove the Circlip inside the case and while holding the bellcrank
and washer in one hand pull the shaft, nut and retaining plate out
the the case, Reassemble these pieces immediatly to keep from
losing the pieces.

4)NEVER mix and match 5th-rev parts from two transmissions
unless you KNOW how to identify the four distinct variations
in these parts which create compatibility issues that will make
you consider self-commitment to a mental institution.

Someone may want to break this post into two parts:
the first being "final disassembly of the M5OD"
And the second being "four NEVERS of M5OD-R1 disassembly"
as Mini articles.

Just remember who wrote it!

AD

 

[1v6pony]

Well thanks everyone.. I got the main shaft out with all the gears on it between the two bearings and just placed it in the new case and put everything back to gether again.. Everything works great and no leaking trans

Thanks Again and here is a photo of the project it was for.
1985 Susuki Samuari with 3.0 vulcan motor and M5od trans mated to a dana 300 Tc with landcruiser axles.. I call it THE TOAD.

Thanks again guys