I have found 2 sources of information on the ratios in an M5OD and they give different gear ratios.

First up is http://www3.telus.net/cbradley/Drivetrain_Ratios.html with

1st 3.40
2nd 2.94
3rd 1.61
4th 1.00
5th 0.75

Second up is http://www.fordsix.com/trucktranny.htm with

1st 3.90
2nd 2.25
3rd 1.50
4th 1.00
5th 0.80

Does anyone have a source or manual that can clear this up? Are their different ratios available for the F150/Bronco depending on 2x4, 4x4, I6, V8, etc...?

 

Well, the only definitive answer you're going to get is if you take the cover off and start counting teeth.

Short of that, look at the telus.net link you posted. The Mazda tranny ratios are exactly the same as the ZF ratios, except for first gear. Since they were made by different companies, that's highly unlikely in my opinion. I would go with what's posted on fordsix.com.

Also, why'd you post this in the six forum?

 

Those ratios from Fordsix look better to me. I know the OD ratio in the Mazda is .8. A 3.4 1st gear with a 2.9 2nd would be stupid. The splits are usually fairly close to 50% in all trannies. 4th is direct, 4thx1.5=1.5 for 3rd, 3rdx1.5=2.25 for 2nd, 2.25x1.5=3.375 for 1st. Trucks are usually a little deeper in the lower gears to help them get moving with a load.

 

Because their has been talk about the M5OD behind the 300 engine. And I figured this would be the best place to ask since I am thinking about a 300 with an M5OD behind it for a street rod.

Is their someplace better to ask?

 

21 years late, but I just started getting into this after swapping to 1 ton axles.
I have a 95 F150 with factory 300 and 2 wheel drive M5OD. My speed to RPMs seem to match up with a .80 5th gear.
My stock axle was the 2.75 highway gears, but currently have a 3.73 Sterling 10.5" from a 99' F350.
if you have an rpm gauge, just start plugging your numbers in an RPM calculator, and you can get a general idea of your particular ratios.


This tells me that changing to 35" tires will drop my cruising speed of 65 to about 1800 RPM, which is right where I like it. But I'm putting in a 4x4 ZF5-42 and transfer case, so I'll have to recalculate for those.

 

The transfer case should be 1:1 so you only need to find the ratios for the ZZF transmission.
Well I kind of lied I guess if you wanted to do low range ratios you could but I dont know of anyone that does for street and most of the time they are running compound low range transfer case.
Dave ----

 

True. It should just be a .76 5th.

 

ZF5:

1. 5.714
2. 2.937
3. 1.613
4. 1.000
5. 0.760

R. 5.238

 

The ZF5 transmissions came in three different ratios.
The earlier versions were designated as: ZF S5-42
The later updated versions were designated as: ZF S5-47

 

I only listed the wide ratio gearing because you can't put either of the close ratio gearing behind a 300. Those were only behind diesels, and, I think, some big block motors like the 460. But small block versions were all the same wide ratio.

Also, not sure why that has the OD listed as 0.77, as it's always 0.76 (I even confirmed this when I had mine apart and counted the gear teeth and did the math, it's 0.760234). But that's a minor point.
And yes, S5-42 is rated at 420 ft/lbs max torque and the S5-47 is 470. Minor internal and external differences were added to beef up the transmission.
The S5-42 should be plenty behind a 300. I have one behind mine and love it!

 

I'm so happy I found a small block pattern one at the junkyard. I was there for small parts, and ended up spending 2 hpurs on my back pulling a transmission. $275? Worth it!

 

AbandonedBronco,
It’s been a while. I’ve seen you on line a couple times at fordsix. Good to see you on line.

There was a typo in the chart that was found on the internet that was posted in post #9. I corrected the error. Thanks for pointing it out.

I decided to post more. I felt that others looking for a ZF5 will need to know more about them. I did purchase a 400M back in 1978 to replace a 351C. I found out that the Housing patterns were different when I started the swap. I don’t want others to make the same mistake by purchasing a ZF5 that is spec’s for a some 335 series engines and all 385 series engines. It could be a costly mistake.

The Close Ratio ZF S5-42 and ZF S5-47 transmissions overdrive ratios are .77
The Wide Ratio ZF S5-42 and ZF S5-47 transmissions overdrive ratios are .76
This is stated in documents.

The Wide Ratio ZF should bolt to: 1965 and later 6 bolt housing pattern 289 V8, 302 V8, 351W V8, 351C V8, 240 and 300 inline sixes.

The Close Ratio ZF5’s were designed to bolt to the diesels that were use in the F250 and F350 pickups. I never personally saw a diesel powered E250 or E350 van with a ZF5. I believe they were available.

The Close Ratio ZF5’s will bolt up to: 351M and 400M “335 series blocks” and 370, 429 and 460 “385 series blocks”.

ZF5 Wide Ratio transmissions are great except for one thing, and in most part, it can be overlooked. “It’s only minor, nothing is perfect” And this is the ratio spread of .61 from 3rd gear to 4th gear. Smaller displacement engines will have to be worked at higher rpm’s some more when hauling up grades. This is one of the reasons that a 408 stroker is popular. In light of this, a full sized 4.9/300 powered Bronco or F series pickup does pretty well as long as hauling up steep grades is kept within reason.

With the proper care, the ZF5’s will last a long time. I personally like the low 5.72 1st and 5.24 reverse gears in my 1991, 2WD, F250, 5.8 V8. They are much better than the Mazda M5OD-R2 transmission in my 1989 F150. But, the Mazda M5OD-R2 transmission is a great shifting transmission with well spaced ratios for an F150 cruising on highways. I think the Mazda M5OD-R2 would work well in a 240 or 300 powered T-Bucket street rod.

 

Weren't the 42s not synchronized as well? I can't remember.
This is the 42 I pulled from a 302 F250, I believe. Complete with transfer case and filled with water.

 

All ZF5’s are synchronized.

 

That's exactly how I found mine. I was there for some random stuff (don't even remember now) and after years of searching I suddenly spotted a 4x4 F-350 with a 5.8 and a ZF5. I called a buddy of mine to come help me pull it because I was not going to leave without it (and I didn't have the tools). I think it was about $200ish as well.

I went from an NP435 to a ZF5, so the spread from 3rd to 4th was an improvement for me . NP435 is 1.79 to 1.00.
That was a frustrating gear spread when pulling up steeper grades as downshifting from 2500 RPM could almost go to 4500 RPM.

The only thing I'm not particularly fond of with the wide ratio is the internal slave cylinder, since you have to separate the engine and transmission to replace it. I wish there was a fix for that. But oh well.