No Such Thing As A Dumb Question

[NickC24]

I had an idea for a thread where people can ask questions without judgment of how dumb it may be. There is no better place of knowledgable bronco people to come to with questions. And a thread where you can ask questions you may have, but feel like it may be too dumb to ask might be a good idea.

Ill go first.

Locking hubs? What is the point of a locking hub if you have a transfer case to select weather you want 4x4 or just rear wheel drive. Also if you are in rear wheel drive, do the axels and mechanics of the front end turn freely or do just the tires spin? Is that the purpose of the locking hubs? To engage the axels when the tires spin even if you are not in 4x4? Never understood this.

 

[doran4x]

Having locking hubs allows the front axle, gears and driveshaft to remain static when disengaged. No movement equals no wear. Engaging front hubs without engaging transfer case means that all those components are moving, creating drag and wear. Also if you have a locking carrier, like a Detroit, then then front end acts weird on the street.


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[SteveL]

Yes. unlocking the front hubs keep all the front end components from spinning while in 2wd. Theory is less wear on tires and front-end parts and better mileage in 2wd.

 

[bronco italiano]

There is also a "binding" that occurs on the street/hard pavement when the front axle is locked. The gear ratios are slightly different from the rear and front axles. That along with any other irregularities, such as uneven tire height can produce binding since they are rotating at a different rate.

 

[ared77]

Great first question and great answers!

 

[BronCowie]

There is no such thing as a dumb question on this site. We are "dumb-question" friendly.

 

[Soylent]

Ok here’s another one. Why is the gear ratio different between front and back? I would think that if you are running 4.10 in the back you do the same in the front. Or is this difference within the transfer case?

 

[doran4x]

Binding is when the transfer case is in 4wd and the front hubs are locked. Difference in gears and tire size will load up the gears in transfer case. Doesn’t happen on dirt because of the slippage between tires and dirt. On the street it can damage the transfer case.


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[thegreatjustino]

Ok here’s another one. Why is the gear ratio different between front and back? I would think that if you are running 4.10 in the back you do the same in the front. Or is this difference within the transfer case?

Go get on a bicycle and take a tight turn around a sidewalk corner where it abuts the grass. More often than not, the front tire will make that turn just fine, but the back tire slips off the pavement and ends up in the grass. Due to the length of the bicycle, the front and rear tires actually travel different distances. Same thing with a 4x4 vehicle. Because the front and rear ends travel slightly different distances when turning, the gear ratios are slightly different.

 

[Wild horse 75]

Ok here’s another one. Why is the gear ratio different between front and back? I would think that if you are running 4.10 in the back you do the same in the front. Or is this difference within the transfer case?

The issue is they never really are 4:10. Since it’s a mathematical equation there is rounding. The only way you can ensure you have the exact same ration it to use the same housing front and rear then use the exact same brand of gears in both. The transfer case shouldn’t change the ratio because they should use the same size input and output gear.

 

[DirtDonk]

The real reason for the different gear ratios in “our” front and rear differentials, is because they are completely different designs.
The rear differential is a Ford 9 inch, the front is a Dana design axle. They are not nearly the same, and that’s just how they came up with ratios.
And some actually were even different among the same ones. For example, one Dana 44 from the factory might have, one ratio, while the gears you can buy for it through the aftermarket are a number or two off.

Besides that, not all trucks do have different ratios. My F350 has the same ratios front and rear because it has Dana 60s front and rear.

 

[m_m70]

I have 4:56 in front and rear.........

 

[Soylent]

So this is the mathematical ratio measured out at the wheel due to the differences in gear brands, housings and axles. The differentials are the same front and rear though, right?

 

[thegreatjustino]

The differentials are the same front and rear though, right?

No, from the factory the rear was a Ford 9" and the front was a Dana Spicer Model 30 or Model 44 depending on the year (mid year change in 1971).

 

[NickC24]

another one for you guys.

I am running into some clearance issue when installing the rear disc brake system from Toms. The shock hits the leaf spring because you have to use the offset bracket to move the shock mount over on the rear end. Everything is already powder coated so I don't really want to be grinding anything.

My question is can you change the "clock" location of the caliper bracket so the caliper is facing more towards the front bronco instead of facing the rear, which is what makes it right in the way of the shock. Is it because of the e-brake? Or can brakes not function in that orientation?

 

[DirtDonk]

So this is the mathematical ratio measured out at the wheel due to the differences in gear brands, housings and axles.

The “gear ratio” is not measured at the wheel.
It’s a ratio derived from the pinion gear and the ring gear tooth counts.
Yes, the tire size is an important part of the equation as far as the real world is concerned. But the numbers we are talking about are strictly between the two gears.

The differentials are the same front and rear though, right?

As Justin already said. The answer to that is, no.
The differentials are different from top to bottom, left to right and inside and out. To note all the differences, you’d have to look at pictures and diagrams and comparison notes.
But suffice it to say, that, even though they function in a similar manner, they are designed and constructed completely different, by the two companies.

That could be an oversimplification, and there may be more similarities than I’m giving them credit for. But basically they are not the same.

 

[Soylent]

The “gear ratio” is not measured at the wheel.
It’s a ratio derived from the pinion gear and the ring gear tooth counts.
Yes, the tire size is an important part of the equation as far as the real world is concerned. But the numbers we are talking about are strictly between the two gears.

As Justin already said. The answer to that is, no.
The differentials are different from top to bottom, left to right and inside and out. To note all the differences, you’d have to look at pictures and diagrams and comparison notes.
But suffice it to say, that, even though they function in a similar manner, they are designed and constructed completely different, by the two companies.

That could be an oversimplification, and there may be more similarities than I’m giving them credit for. But basically they are not the same.

So what you are saying if I have a 4.10 ring and pinion in my rear 9” housing I will have a ring and pinion with a different ratio in the D30 up front?

 

[Glass Pony]

I had an idea for a thread where people can ask questions without judgment of how dumb it may be. There is no better place of knowledgable bronco people to come to with questions. And a thread where you can ask questions you may have, but feel like it may be too dumb to ask might be a good idea.

Ill go first.

Locking hubs? What is the point of a locking hub if you have a transfer case to select weather you want 4x4 or just rear wheel drive. Also if you are in rear wheel drive, do the axels and mechanics of the front end turn freely or do just the tires spin? Is that the purpose of the locking hubs? To engage the axels when the tires spin even if you are not in 4x4? Never understood this.

Nick,
I've been here over a decade, and I have seen how some other sites are and there is some real a..holes out there but I would think this would be the last forum for the need of a "safe space".
Yes, there might be some good-natured ball busting but usually that's in the "Off Topic" section.

 

[DirtDonk]

So what you are saying if I have a 4.10 ring and pinion in my rear 9” housing I will have a ring and pinion with a different ratio in the D30 up front?

Yes. Virtually every time…
I don’t remember the exact numbers, but a Dana front end might be a 4.09 or a 4.10 or something along those lines, to the Ford’s 4.11. And a Dana 44 could be even different. Dana 60 as well.
Some gear ratios might actually match exactly between the two different designs. For example, possibly a 3.00 ratio in one, might also be a 3.00 in the other.
I don’t know this, of course, and I don’t have all the numbers memorized anymore like I used to when I sold ring and pinions daily, but you get the point.

It’s also possible that all those numbers are arbitrary just to differentiate (no pun intended) and to the previous point about them being rounded up or rounded down, maybe a Dana and a Ford do match exactly, but for purposes unknown, they use different rounding techniques to come up with the slightly different numbers.
I don’t think so, but I’ve never actually sat down with a calculator and bothered to figure them all out down to the n’th degree.

 

[Soylent]

Wow. I never would have thought that. Underlines how you can damage them if you lockup on the street, even in the rain.