55.2-59 59 Gearing for long legs

[BlouDon]

Having explored various options of extending the 59's legs for better open road cruising, I have decided doing as follows:

Fit the 6-stud rear axle of a Ford Ranger 2.2 6-speed manual 2WD with a diff ratio of 3.15.

This will have the following benefits:
1. Original engine / 3-sp manual transmission retained;
2. Significantly improved ratios for open road cruising;
3. lower prop shaft RPMs produces less vibrations - in theory. I might even end up using the Ford propshaft which has a centre support bearing ;
4. diff in this axle comes with electronic diff lock - FWIW;
5. Solves the oil leak problems that exist on OEM axle.
6. I should be able to use the ABS sensor outputs to drive a digital speedometer - if I ever do this;
7. will allow me to retain the existing original instruments since speedo cable drive input comes off transmission - it will be reading way too low of course.
8. The mod is fully reversible and not in-your-face "visible".

The attached graph showing the effect of the new diff ratio as well as the ID sticker of the axle.

[mongocanfly]

I'm guessing from your chart you have a 3 speed trans...what size tires are you running?

[BlouDon]

Originally Posted by mongocanfly

I'm guessing from your chart you have a 3 speed trans...what size tires are you running?

Correct on the 3-sp. But even if it was 4-sp, little changes because 4th would also be 1:1.

I intend running as close to the 29" (6.50-16) as per the original spec. It is currently fitted with BFG A/T 235/70/16 but I intend removing those (they don't look nice on the truck and replacing them with a more road oriented 30" 255/70/16 (that comes off a Ford Ranger) - which I have lying around. They might be a bit wide, but I'll see when I fit them.

Tyre size obviously affects gearing but I find that one must make huge changes to have a meaningful change in gearing.

[mr48chev]

Interesting, your Ford Ranger must have a different axle / lug pattern than the Ford Rangers in the states.

Wheels that you want to use bolt on, correct width or close enough, Right gear ratio for what you want to do. Parts such as wheel bearings and seals readily available locally, reasonable cost all work in the go for it factor.

The small Ford Rangers (since 1983) here have a 5 on 4-1/2 bolt pattern while the early full size Ford F 100 top line truck was called a Ranger between 1965 and 1981, It had a 5 on 5-1/2 pattern That adds to the cross the ocean confusion.

[mr48chev]

I have never actually checked the ratio in the Chevy Nova rear (md 70's) that I have under my 48 but imagine that it is 3.0 or close. I used to get 20 mpg and cruise at 70 when I first put it in. The 3.15 would be a bit better.

I haven't tried this calculator but you might have fun with it https://www.blocklayer.com/rpm-gear.aspx

Here is one that shows you the effect a tire size change has with nothing else involved. https://tiresize.com/gear-ratio-calculator/

Here is another one. http://www.businesspath.com/business.../rpm-calc.html

This one intended for electric cars is probably the simplest one to use of any. Plug in three factors and get the fourth. It's one that is great for the quick "what if" questions that come to mind on tire size and gear ratio. http://www.advanced-ev.com/Calculators/TireSize/

[burnin oil]

When I was in australia the rangers looked like f150s. You will notice in the international markets that the mini trucks are more designed to work than here. They also have better drivetrain options. It's nice seeing a tv commercials for new trucks that are diesel, manual, and 4x4 for under 30k US! Most of the world just doesn't have large pickups so the minis have to fill that void.

[BlouDon]

Originally Posted by burnin oil

When I was in australia the rangers looked like f150s.

Its the axle from this truck that I will be using: https://www.ford.co.za/commercial/ra...mt-4x2-hr-FAF/

Our Ford Rangers are indeed smaller than the American F150, although they are not "small" or "mini" at 5.35m in length.

[mongocanfly]

I asked about the 3spd to make sure you didnt have a od trans....
But correct....3 or 4 spd with final 1:1 is same results
With those 3.15 gears, 1in difference in tire height is around 85rpm difference at 70mph..

Heres the one I use..http://www.csgnetwork.com/multirpmcalc.html
With the 1:1 trans...3.15 gear...29in tire..I'm showing 2555 rpm at 70mph
Same but with a 30in tire shows 2470 rpm at 70mph

[BlouDon]

Originally Posted by mongocanfly

With the 1:1 trans...3.15 gear...29in tire..I'm showing 2555 rpm at 70mph
Same but with a 30in tire shows 2470 rpm at 70mph

There we have confirmation that upping the tyre has a rather small effect on gearing.

[dsraven]

https://en.wikipedia.org/wiki/Ford_Ranger_(T6)

is this the same vehicle? will the track width work for your task force of will it be a bit wide? dimensions given are likely body dimensions. have you done an actual track width check? what I like to do is use a flat tool vertically against the tire on the outside sidewalls each side, mark the floor each side where the tool touches, then move the vehicle out of the way and measure between the marks on the floor. pretty close to actual that way. it takes into account the bulge in the tires though. the best would be to have the vehicle off the ground or jacked enough so the bulge in the tires is not in the equation. then mark the floor.

[mr48chev]

That basic chassis/body wasn't imported into the states and is the reason we here don't know the truck. https://en.wikipedia.org/wiki/Mazda_B_series

Looks like they have/had a narrow axle version and a wide axle version with two body widths. I'd think 2 wheel drive vs 4 wheel drive similar to the S 10 here.

That fits right into the available, supported and affordable there thing.

[bobinbc]

The specs list the track as approx. 61.4 " which puts the actual diff width about an inch or so wider so that sounds like a good fit.

[BlouDon]

Originally Posted by bobinbc

The specs list the track as approx. 61.4 " which puts the actual diff width about an inch or so wider so that sounds like a good fit.

Very close call!! Indeed the Ford axle is about 70mm (2.75")wider than the Chevy's. This would then be like having a 35mm (1.38") spacer between the drum and the wheel (which is possibly not a bad thing). When I collected the axle today, I was told it comes off a "Hi-rider" (a 2wd with the same high stance of a 4x4)

So it seems there are at least TWO versions of the 3.15 Ford Ranger axle... One for std height and one for the "Hi-Rider".

But... there also seems to be a (rusted) 15mm (0.6") spacer between the brake back plate and the axle flange. I wonder what the chances are of that spacer being put in by Ford to widen the stance for the hi-rider compared to the std height models...??? I'll find out if there is a difference in part no's for the sideshafts between the two models. If not, I should simply be able to remove that spacer - if the wider axle presents issues.

Being a hi-rider axle, this means the spring landings are on top of the axle. Sadly they are mounted further apart than what the Chevy requires, so I will have to make new ones.

I will also have to modify/fabricate shock mounts.

I also took the prop shaft. Not sure if I will end up using it as then I would have to mount the center bearing (more work...)

In the pics you can also see the connector for the Electrical Diff lock on the pumpkin as well as the ABS sensors (which I'll use for the Digital speedo).

[BlouDon]

There it is!

The Ford rear axle fitted. I had to effectively move the spring landings a bit toward the centre, make them narrower, remove the old shock mounts.

Still have to sort brake lines, propshaft and handbrake.

I think it looks lovely with the trackwidth now about 70mm wider.

[whitedog76]

What kind of diff. Is that? Looks like a 9"

[BlouDon]

Originally Posted by whitedog76

What kind of diff. Is that? Looks like a 9"

Its off a Ford Ranger that is available in South Africa, Australia, New Zealand (and UK?): https://www.ford.co.za/commercial/ra...mt-4x2-hr-FAF/

[whitedog76]

I was actually trying to figure out what Ford actually calls it. Here in the states the "new" Ranger uses a Dana M220, which is a modified Dana 44. The Jeep Gladiator and Wrangler use the same differential.

[BlouDon]

Took her for a drive today - now with the Ford Ranger 3.15 rear axle.

I'm REALLY pleased with the outcome!!

I was worried that 1st may be too long, but its fine - for a truck that will never again carry a load or tow heavy. The heavy flywheel helps a lot. It would have to be a seriously steep hill for 1st to be a problem. I find the lack of synchromesh a bigger problem.

Cruising along at 65mph is really pleasing with the engine not stressed at all but still have enough grunt to climb mild inclines in 3rd. If it was not for the external sun visor, I'm confident she would have no objections to cruise at 75mph.

The plan was to do a front disc brake conversion, but I am now very happy with braking which is very responsive and immediate and the front disc brake conversion is - for now - now off the table. Braking hard (I have not tried locking up the fronts yet), I don't get rear wheel skid like I do in my C10. So it seems brake balancing is very close to ideal.

Hand brake is not connected up yet.

An unplanned bonus is that my real speed in km/h is exactly double the figure shown by the mph speedo as verified with the WAZE app. So, now there is no need for a km/h speedo or dash mods.