Hey all...been wondering about a few things:
1. is there a retro fit american made trans for this?
2. is there a overdrive that bolts on behind this o/d transmission?
3. can I use a different fluid instead of the ATF style?
THANKS!

 

Not with OD. You can use a BW T-18 4-speed granny gear trans if you don't mind giving up OD. That trans was optional on these trucks until about 1992 or so.

The heavy duty OD trans is the ZF5 but that's not American made.

 

huh. but an optional behind the tailshaft o/d will work? and i’d have a direct throw out bearing set up right?

 

The M5OD-R2 trans you have has an integral bellhousing. The T-18 does not, so you will need to get a bellhousing that fits your engine. Since you currently have a hydraulic clutch you probably want to get a bellhousing from a later truck that also has a hydraulic clutch. Earlier (before about '83?) used a mechanical linkage. I could be wrong but I don't think it's easy to put a hydraulic clutch in a bellhousing that was intended for mechanical.

As to putting an overdrive behind the T-18, you probably can. But you'll need to get that figured out separately.

There are also other 4 speeds similar to the T-18 you might want to consider. The T-19 is essentially the same trans but with a synchroed 1st gear. And the NP435 is very similar to the T-18.

Also the T-18 was available in Ford trucks as a wide ratio with about a 6.6:1 granny first gear. But it was also available in Jeeps as a close ratio with a 4:1 1st gear (still non-synchro). I believe the cases are the same, but input shafts might be different, so you might want to look into that a little before you just buy the first T-18 you find.


Back to your original questions, check with someone like Gear Vendors to see in they have an overdrive that will go on the back of an M5OD-R2. I know they do for an E4OD, so it's not like they completely ignore overdrive transmissions.

And sorry, I can't answer your question about using something other than ATF.

 

From what I know, you need to run ATF in the Mazda trans. Something about bearing types and clearances. The older 4-speed non-ODs use gear oil.

 

what truck and engine?
you may be able to put a ZF-5 in place of the M5OD

 

Thanks to all so far! Many things to think on.
My truck is a 1995 F150 Eddie Bauer, reg cab, 300, 5 spd o/d, 4x4.

 

That wouldn’t fit the requirement of question #1

 

the ZF came stock in ford trucks just like the mazda did, so it is close enough to "american made"

 

What are the reasons for such??

 

If you put differential oil in either the ZF5 or Mazda 5 spd, you'll ruin in them in short order.

Both of those transmissions can handle some abuse, but if you leave your hand on the shifter, it will wear the shift forks out.

What are you looking at accomplishing swapping to something other than either standard transmissions?