M5OD why did they choose the ratios they did for each gear?

[Eddo Rogue]

Every time I drive my ranger, I think of how off the ratios are as I shift. Especially when I can often skip gears. I wonder if they come in different ratios and why they chose the ratios they did. I feel like its always high or low depending on the gear, not much sweet spot.

If I had my druthers here is what gears I would change, pun intended.

1st gear would be much lower.
2nd gear would be slightly lower or same.
3rd gear would be very slightly lower.
4th gear would be same.
5th gear would be slightly taller.

With my slightly larger than stock 31" tires, I cant idle in 1st slow enough for parking lots (gotta keep clutch slipping), and yet still screaming in 5th gear at normal highway speeds (>70mph).

Do all M5OD have the same ratios? If so, why did they choose the ratios they did for these trucks?

 

[Shran]

2.9, 3.0 and 2.3 M5OD’s had slightly lower 1st, 2nd and 3rd gears. 4.0’s were geared higher. It’s not a huge difference but I’m with you on what they SHOULD have been.

 

[sgtsandman]

I've found the gear ratios in the transmission to be fine over all. Now the disparity between a manual equipped vehicle and being stuck behind someone with an automatic is annoying. They always seem to be going just the right speed that the lower gear is too low and the higher gear is too high. Maybe when I regear the differentials, that will change....

 

[SenorNoob]

This^. Except I feel the same way when following anyone. I can never find a gear that makes the truck happy to cruise. At least in high range. 4th low is between 1st and 2nd...

 

[Brain75]

I think a big part was the 55 mph speed limit and Ford's cheapness not to change something that they already poured R&D money into making less than 10 years earlier.
The 70's repeal of the 75mph speedlimit was thought to be permanent, and even the 1987 partial rollback (allowing 65) was a fantasy where I lived, speedlimit was 55 on all roads I drove on until the total repeal in '95.... why Ford didn't re-gear in 95 is a bit of a puzzle, but like I said they didn't want to spend more R&D and just kept chugging out the design they had made just a few years earlier. Plus the enviro people were campaigning hard to keep 55 or make a new law basically doing the same - it saves gas to drive slower.

I notice the guys complaining are all 4.0 owners and I am reasonably happy with mine (I have a 2.9) other than the fact that my brain doesn't like seeing > 3k rpm at long duration cruise (and at 75mph the tach says I am over 3k) and of course the flaws in the slave clutch.

 

[Brain75]

I did a buttload of research (one whole winter) on Ford's manual transmissions from 1948-2012, and developed a spreadsheet of all the options (I was looking to put a modern 4 or 5 speed into my 1948). I ended up going with the T-5 (the Chevy version since the World Class one's in mustangs were unicorns around my woods and people made adapters to put the Chevy version in). Ford was all over the map with "close" and "wide" transmissions, it kind looked like they threw a dart at the wall and decided that would be the gear ratio a lot of times.

I myself like a wider transmission so you have more power for pulling and heavy loading but still have decent fuel mileage once you get to the top end... some of the extreme's Ford did are like the T170 (1st was 2.32 and 4th was 1.0), and the NP435 (1st was 6.68, 4th 1.0) - that is some ridiculous difference. The NP435 (F-series) is a bit ridiculous, 1st is truly a granny gear and it was only really a 3 speed, but 2nd to 3rd was like falling off a cliff. (jumping from 3.34 to 1.66).

One thing that I learned in all that is you can fix a lot of transmission gearing issues just by swapping the rear diff ratio. In fact that is my latest give back to the site - I redid the RPM chart for tire/diff/trans swaps. (Jim is still working on incorporating it cause it is a calculator with javascript so fights his google ads javascript)

 

[scotts90ranger]

If you think the M5OD is bad don't attempt to drive a F350 with a 7.3L diesel and a ZF5... at least mine with 4.10's and 35" tires there isn't a gear that will drive at 35mph in town without lugging or screaming and towing heavy going up hill the difference between 3rd gear and 4th gear at say 40mph (it's stock so 225hp, it happens often) is like 900rpm... so I end up at 38mph in 3rd gear at 2500rpm a LOT, and that's the "close ratio" version...

 

[Eddo Rogue]

I've found the gear ratios in the transmission to be fine over all. Now the disparity between a manual equipped vehicle and being stuck behind someone with an automatic is annoying. They always seem to be going just the right speed that the lower gear is too low and the higher gear is too high. Maybe when I regear the differentials, that will change....

Lol its like theyre watching and know to keep you perfectly between gears.

Around here on the multi labe freeways it helps swooping over to the right two lanes when traffic hits, and follow the big rigs. They are better about maintianing steady momentum trying to sweet spot way more gears, and the prius/tesla gang tend to stop/go slow in the passing left lanes anyways.

 

[Eddo Rogue]

Great replies, I learned a thing or 3.

In regsrds to traffic/ speed limits keeping you perfectly between gears, Im at least glad its not just me.

In regards to gearing ratio change:
-A higher axle gear ratio would fix my 5th gear rpms, but makes the other gears too far apart, and 1st would be way too tall.
- Lower axle gear ratio would fix 1st through 4th, but make 5th way too low.

I probably need lower gearing anyways...one time on a dirt road but very sandy section I couldnt pull 1st gear in 4hi...had to use 4lo and scream 4th gear to chug along. Ride was smooth but drivetrain probably wasnt. I beat on my college ranger 20 years ago, and baby this one now.

 

[Eddo Rogue]

If you think the M5OD is bad don't attempt to drive a F350 with a 7.3L diesel and a ZF5... at least mine with 4.10's and 35" tires there isn't a gear that will drive at 35mph in town without lugging or screaming and towing heavy going up hill the difference between 3rd gear and 4th gear at say 40mph (it's stock so 225hp, it happens often) is like 900rpm... so I end up at 38mph in 3rd gear at 2500rpm a LOT, and that's the "close ratio" version...

I think in your case a lower axle ratio would fix it, as it would bring all the gears closer together, just raise rpms in top gear at speed, which you didnt mention is an issue. If you can compromise a few rpms at cruising speed up top, I'd do a gear swap.

 

[Brain75]

Changing rear diff will not bring the gears closer together - almost nothing you can do to do that, it will change your shift points (so instead of shifting at 20/30/40 you will do 25/35/45 or similar). If you are considering a diff swap, probably the best thing you could do besides staring at the chart is plug in all the relevant into this https://www.blocklayer.com/rpm-gear and then seeing where your shift points are... I haven't seen enough of a consistency in my traffic jams to get obsessed with moving shift point from 25 to 20 or 30, but speedlimits around here are very set and that is what I match to (65 state roads, 75 interstate)

 

[scotts90ranger]

I think in your case a lower axle ratio would fix it, as it would bring all the gears closer together, just raise rpms in top gear at speed, which you didnt mention is an issue. If you can compromise a few rpms at cruising speed up top, I'd do a gear swap.

Unloaded and up to say 12k pounds total weight everything is perfectly fine, cruising at say 62mph is right around 2000rpm in 5th which is perfect for the engine, even 200rpm faster and the fuel starts flowing faster and the mileage goes down no matter what gear... If I got some stage one injectors, a tuner and an intercooler to gain 75hp I'm pretty sure I could just hold 4th on the long hills around here which would be perfect, it's on the list which I need to do this year.

By "screaming" what is your cruising speed and rpm now as well as gear ratio? If you can't hold first in parking lots I'm assuming 3.55 or 3.73. I'm pretty sure you might be overthinking what is bad rpm to hold for long periods, on my 2.3L the fuel mileage goes down when I hold over 3000rpm, in my V8 Explorers it seems to be 2k, the 4L is likely somewhere inbetween...

in my '90 with 5.13 gears and 35" tires it works pretty good for me with the lack of bottom end, with a 4L I don't think that would be as necessary and would probably want 4.56's or it wouldn't be highway friendly as I'm sure 3k at 60 isn't ideal but the 2.3L doesn't care...

 

[85_Ranger4x4]

M5ODR2 is the same. First and reverse are stupid fast. OD is too low.

 

[arse_sidewards]

I wonder how many people bitching about the tall 1st gear have ever actually driven a transmission with a respectably deep 1st gear. All that spinning mass doesn't do great things for shifting. The M5OD is actually really well spec'd out for what it is and what it got installed in. I've grossed 12k combined with my Ranger and other than wishing literally every gear was lower I can't find fault with the splits.

Low range in the transfer case covers for the transmission just fine since you can upshift at a ~5mph roll pretty well. The sliding dog in every transfer case I've ever had apart is beveled to facilitate this. That said, even ignoring the lack of synchro, this is a really shitty upshift on account of the huge gear split and reduction in RPM. The only reason it actually "works" when loaded is because the following gear (1st, high range) is sufficiently deep. This huge 1st/2nd drop is exactly what driving The 1.68 split of the normal 1st/2nd is actually pretty good because you can maintain RPM and acceleration.

What the M5OD could use, other than a deeper reverse, is a 6th gear below first.... Which is exactly what they did on the new Broncos.

 

[Curious Hound]

I wonder how many people bitching about the tall 1st gear have ever actually driven a transmission with a respectably deep 1st gear. All that spinning mass doesn't do great things for shifting. The M5OD is actually really well spec'd out for what it is and what it got installed in. I've grossed 12k combined with my Ranger and other than wishing literally every gear was lower I can't find fault with the splits.

Low range in the transfer case covers for the transmission just fine since you can upshift at a ~5mph roll pretty well. The sliding dog in every transfer case I've ever had apart is beveled to facilitate this. That said, even ignoring the lack of synchro, this is a really shitty upshift on account of the huge gear split and reduction in RPM. The only reason it actually "works" when loaded is because the following gear (1st, high range) is sufficiently deep. This huge 1st/2nd drop is exactly what driving The 1.68 split of the normal 1st/2nd is actually pretty good because you can maintain RPM and acceleration.

What the M5OD could use, other than a deeper reverse, is a 6th gear below first.... Which is exactly what they did on the new Broncos.

I really have no complaints about my M5OD. A lower first would be nice offroad. But for normal driving, its’s fine. I rarely use 5th anymore. But thats due to aerodynamics. 6” lift, altered body shape, big heavy tires, etc. and it has grown to over 5,000 lbs. My truck isnt like anyone elses. That’s why i haven’t really chimed in here until now. But my little transmission works hard for me.