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M5OD to ZF5 Swap

21K views 21 replies 6 participants last post by  hms79 
#1 ·
Hey, all.
I have recently purchased a 1990 Bronco with a 4.9L (300) inline six with a 5-speed transmission, which is the M5OD. I am not happy with the tranny at all. It is hard to get into 3rd gear, and likes to jump out of 3rd, also, it just seems weak to me. The previous owner claims this is a new transmission, but I am not so sure. The Bronco has 142,000 miles, and runs great, I am just not thrilled with the tranny. I know this is not a difficult swap to a ZF5, but my big questions are 1.) Who has done it? 2.) What is the cost? and 3.) What are the major differences?

I have searched and read all of the post about the swap, and I know it is a direct plug and go type of swap, just looking for a little more insight.

Thanks!
 
#3 ·
the M5OD to ZF is (almost) plug and play. a connector for the reverse lights may be different?

I know a guy here did it, and he said it was just like pulling the trans and putting it back in. everything bolted right up. i don't remember who though.
 
#4 ·
Only cost to you is the cost of the trans and maybe a new trans mount if yours needs it. Then again check out your clutch and slave cyclinder while your in there, its always a good idea to change the throw out bearing too. And like stated before its a strait swap.
 
#5 ·
The differences between the two (besides strength) are the gearing:

M5OD

1: 3.90
2: 2.25
3: 1.46
4: 1.00
5: 0.80

R: 3.41

ZF5

1: 5.72
2: 2.94
3: 1.61
4: 1.00
5: 0.76

R: 5.24
 
#7 ·
The differences between the two (besides strength) are the gearing:

{Mazda} M5OD {R2}
1: 3.90
2: 2.25
3: 1.46
4: 1.00
5: 0.80
R: 3.41

ZF5 {M5OD-HD wide ratio}
1: 5.72
2: 2.94
3: 1.61
4: 1.00
5: 0.76
R: 5.24
x2! :) and-the-main-reason I didn't want a Mazda "M5R2" in my Bronco.
Wanted a granny gear and didn't want to have to use 1st to get going.
Wanted it to be like my '75 F150 T18 but with overdrive. :)

There are some close ratio ZF's out there, but I don't know what bell
housings they got or if the gears will swap over etc. Ford didn't -only-
use those close ratio ZF's with diesels like you read some places, BTW.

Alvin in AZ
 
#6 ·
...just looking for a little more insight.
Do it from above with an engine hoist and it's an easy do it by-yourself
project. BTDT by myself and with helpers from below using bricks and
boards and stuff too, but the engine hoist method kicks butt, IMO.

Take the seats and carpet out and wash the soda pop out of the carpet. xD
YMMV, but mine ran-brown as anything while draped over the clothes line
and being sprayed with the garden hose.

--------------------

Go to a DIY car wash and clean off all the grease/dirt you can first?
(just got done doing that with the wife's Merc that was due for a timing
belt change and a PS-hose-change-even-more!, worked great)

--------------------

Read where Ford had used a different type of hydraulic connection on a
Mazda M5od-R2's slave at some point? ...anyway, the guy got it together
before noticing that. The sorry sucker never got back and told us what he
did to "fix" it. :/ I'd suggested he buy a new pressure line with the correct
{ZF} connector already on it. He too was swapping from Mazda to ZF.

-----------------------

Sheets of cardboard from Costco etc is cool stuff to work on, it's kinda slick,
you can scoot around on it like a cheapassversion of a mechanic's creeper.

-----------------

BW-1356-E = is a measly 76#
2wd ZF is 150# = 2wd T18 without its cast iron bellhousing = another 32#
2wd ZF with flywheel and pressure plate = ~230# = 4wd E4od.

Also, you can mashtheshitoutofa "modern" bath scales with a E4od. xD
Turn it into a V shape! LOL :)
Can weigh an E4od using a bath scale from the 60's without damage tho. ;)

Alvin in AZ
ps- An engine hoist can be used for other stuff. Me and a buddy loaded a
windmill head into the back of my pickup using my engine hoist and when
I got to the ranch it was going to, unloaded it by myself before the other
guy even showed up. Me and my wife loaded the old 4wd E4od we were
giving away into the Bronco (230# with torque converter) on Thanksgiving
day, delivered it no sweat. Ever had turkey with chorizo stuffing in it? LOL :)
 
#8 ·
As far as I've read, the diesel has a close ratio and wide ratio available. The gas only has the wide ratio (which is the one listed above).

I personally would be okay with the M5OD. My Bronco is pretty much the only truck I've ever driven.....ever, and it came with an SROD transmission. Learned to do plenty of off-roading and driving without a granny gear. But overall, they're both street transmissions.

The ZF5 is about as close to perfect as you are going to get. Robust. Granny gear. Overdrive. It has it all.
 
#9 ·
As far as I've read, the diesel has a close ratio and wide ratio available.
The gas only has the wide ratio (which is the one listed above).
Oops!:/ I got that backwards then? LOL :)
Well, so much for me knowin' sumthin'. :/
I personally would be okay with the M5OD.
My Bronco is pretty much the only truck I've ever driven.....ever,
and it came with an SROD transmission.
Learned to do plenty of off-roading and driving without a granny gear.
But overall, they're both street transmissions.
Hmmm... you know VW based dune buggies are setup like you SRod since
4th was a little bit overdrive. There wasn't a 1:1 in those old transmissions
if I remember right.

There's a transmission rebuilder on ForDification.com (Bump Side website)
And he sez that the Mazda M5R2 close ratio is what he likes best for hauling
broke-down cars on a trailer behind his old Bump Side. Claims the M5od-R2
can be strengthened somehow too.

The ZF5 is about as close to perfect as you are going to get.
Robust. Granny gear. Overdrive. It has it all.
Yeah that's true but I can "dream-up" something I'd like better and that's
a "T18 with overdrive". LOL :)

They make an NP435 with overdrive, too bad they dropped the ball on
5th gear...
http://www.quad4x4.com/NV4500 5th Gear Failures and Solutions.htm

---------------------------

TheUnforgiven said:
the M5OD to ZF is (almost) plug and play. a connector for the reverse
lights may be different?
I'm guessing that the Mazda has a different "backup light switch" then?
Since my '90 ZF's switch is the exact same type that's on my '75 T18. :)

Alvin in AZ
 
#10 ·
i was throwing that out more for reference that it truly is a 99% bolt in. i don't know if they are different or not, i just didn't want to tell the OP "oh yea, suuuurreee complete bolt/plug in" and then have him come back to say "unforgiven is a fawking dick, it's not bolt in blah blah bitch bitch..."
 
#11 ·
It very well might. My SROD had a different back up light plug than the NP435 I put in.


Now, what would be an awesome transmission is the NP540. 5 speed transmission used from the mid 50s to the late 70s. Used in Fords, but probably a different bolt pattern.

1 - 7.41
2 - 4.05
3 - 2.40
4 - 1.48
5 - 1.00
R - 7.85

Just lower your final drive a bit (I'd swap in a 2.73 in mine), and it'd be like having a granny gear and an "overdrive".
 
#12 ·
Thanks guys, for the info. I have no carpet, so I don't have to worry about cleaning that up!
IMO, the M5OD just doesn't seem very strong, and I really would like to have a granny gear. My Bronco is just a toy, and to help get family members around in case of snow (my sister has a mustang). I am looking for something that would be a direct bolt, and just cost me the tranny and a few minor parts. The clutch and those things I would consider part of it, especially at the truck's age. The original owner claims these are all new parts, but I am finding out they aren't. I don't really care, as I didn't buy it to be a daily driver. In fact, I would even be OK with a four speed if it would be feasible.
 
#14 ·
If you're not really concerned with highway driving, a 4 speed would be right up your alley. The NP435 is about as robust as they come, has a super deep granny gear, and would be a direct bolt in. You'd just need to find a hydraulic clutch bellhousing. Also, the lengths of the tranmissions (and therefore the driveshaft) MAY be different, but I'm not sure.
They're also MUCH MUCH cheaper than a ZF5.

I have NP435s in both my Broncos. They're both 300s. One has a 3.00 rear end and one has a 3.55. They're both great to drive around, and neither is all too bad on the freeway either.
 
#15 ·
Abandoned....having set up the hydraulic bellhousing and changing driveshaft lengths doesn't sound like bolt in to me...
 
#16 ·
Heh, sorry. Considering what I had to do to swap from an SROD to an NP435, that's nothing. :)

You'd need the bellhousing with the transmission, but if you did, it'd bolt right in. And I *think* the transmissions are the same length. If not, the drive shaft would be the only modification.
 
#17 ·
isn't the hydraulic np435 an external slave?
 
#18 ·
I forgot about that. That's true. But don't the ZFs just have a nipple sticking out for the slave? I thought you'd just take the hydraulic line and put it on that.

So maybe not bolt-in, but not an extensive amount of work.
 
#19 ·
If you add in the cost of the hydraulic bell housing with the NP435 tranny, wouldn't that probably almost equal the cost of the ZF? Just a question. I honestly don't care much about highway driving my Bronco. I drive it to work maybe twice a week. I mostly just drive it around home, and off road it, and use it for chores around the house. Fuel economy and highway driving mean nothing to me. Does anyone know where I might find out about swapping my M5OD for the NP435? The granny gear is really what I want for pulling. I cut a lot of wood, and while it currently doesn't have any problem pulling trees, I just feel like the M5OD is weak in this area. a granny gear would be welcome in this venture.
 
#20 ·
If you add in the cost of the hydraulic bell housing with the NP435...
wouldn't that... almost equal the cost of the ZF?
Seems to me that'd depend on the wrecking yard situation near you. ;)

Since you want granny-gear above all else that's the only way to go
IMO because the wide ratio ZF's 1st gear ain't all that low. :/

Look for a bellhousing to fit your engine and its cost before making
up your mind? Be careful with that tho, we're talking Ford here. ;)
Ford prob'ly made a dozen different ones that'd fit a 300i6 and only
one will do what you want ...chances are! LOL ;)

Alvin in AZ
 
#22 ·
M5OD to C-6

I know I am about to drive you all crazy with this, but what about a C-6 swap? Would that be feasible to do? Would it be easier to do a swap to a E4OD? AOD? I am just brainstorming here, looking at all my options before I decide anything.:thumbup
 
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