Sterling 10.5 vs 9" hybred axle

[1969]

So, circling back to the (one kind vs the other kind while pointing out 9" flaws) discussion.. I've had an ARB in a Currie branded 9" Daytona case for 20-something years, in a Currie very beefy housing (my description) that they haven't made for ages. Explorer brakes. 31 spline axles. Blah blah. If my ARB grenaded tomorrow (unlikely, given how I drive, but still..) I would rather replace the entire axle than give up on the ARB. I don't use the capability often but when I do I'm sure glad it's there. No way will I ever run anything but a selectable locker.

So, someone with knowledge (I'm thinking you @jamesroney) please describe, ignoring cost, a replacement not- 9" rear axle, gotta be 5 on 5.5" ARB compatible rear axle. Dana 60, Sterling, what ever.

https://www.supermotors.net/registry/25989/84286-2

This guy got a custom set of 5 lug axle shafts from Dutchman to convert the Sterling. You can even get the axle with a factory e locker as well on some of the 2011 and newer axles.. or you can get any 10.5/.25 axle and order the factory ford e locker for about $500.

 

[jamesroney]

So, circling back to the (one kind vs the other kind while pointing out 9" flaws) discussion.. I've had an ARB in a Currie branded 9" Daytona case for 20-something years, in a Currie very beefy housing (my description) that they haven't made for ages. Explorer brakes. 31 spline axles. Blah blah. If my ARB grenaded tomorrow (unlikely, given how I drive, but still..) I would rather replace the entire axle than give up on the ARB. I don't use the capability often but when I do I'm sure glad it's there. No way will I ever run anything but a selectable locker.

So, someone with knowledge (I'm thinking you @jamesroney) please describe, ignoring cost, a replacement not- 9" rear axle, gotta be 5 on 5.5" ARB compatible rear axle. Dana 60, Sterling, what ever.

It's slightly more complicated than @nvrstuk said. So I'll start with a question.

5 lug or 8 lug. This is a really important question that I wish I had answered 20 years ago. But my answer came back 5 lug, which has resulted in significant expense. But I always wanted to be able to share/swap spare tires on the trail. Turns out that doesn't happen as often as it used to.

If the answer is 8 lug, then the answer is the 14 bolt.

If the answer is 5 lug, then more questions. Whose brakes are you going to run? If that answer is Explorer or Wilwood - disc with shoe parking brake, and you are running semi float 35 spline axles...then the Sterling or Dana starts to look better. The last question is driveshaft length/angle. If you are in an EB with a long drive train, then a high pinion starts to come into play. Finally, there is ground clearance.

The Set-20 bearings use 1.562 journals, and accommodate Big Bearing 9 inch brakes. The GM corporate 14 bolt uses 1-9/16 x 30 spline axles. 1.562 is awfully close to 1-9/16. So I don't think they make 14 bolt semi float shafts in SET-20. You kinda want to stay at 1.5 inch x 35 spline. Which defeats a small part of why the 14 bolt is the winner.

If I ignore cost, then I wouldn't know how to answer. I don't know how to do that. Cost is always a factor. But if I could have anything I want...(and I suppose I can...) I always end up with a 35 spline, semi float, 5 lug dana 60 with an ARB. When I'm feeling spendy, I use the Dynatrac pro-rock 60 housing. It's basically a shaved 60 housing with the ground clearance of a 44. But usually I try to find a junkyard 60 from an Econoline 250 Van on 1/2 price day at the pick-n-pull. Then I weld on Billet Torino ends, and throw on some Explorer brakes. Still have to source axles, but that's never not true.

But in your case, I'd just bump up the air pressure on the 9 inch ARB compressor and run it for another 20 years.

 

[Yeller]

Dana 60 or 14 bolt is always a debate. I’m with @jamesroney on the selections and why. However I really want a full float 5x5.5 hub on my Dana 60, it is completely not necessary but I want it lol.

As another option that I would do today without a second thought. Super 8.8, they are stout, nearly equal to a Dana 60, and have a much larger wheel bearing, which equals a much larger shaft at the hub, which cures the week link of 35 spline axles with a set 20 bearing, the wheel flange, that is the week spot in that arrangement. Oh and Moser makes axles for them in any bolt pattern you want. Now that being said what I haven’t seen is how strong is the differential, it is wider than a 9” but not much larger in diameter, time will tell.

 

[ntsqd]

I went 8 lug D60 under the rear of the FSB. I weighed staying 5x5.5 and doing so was going to cost a lot of time and money. I chose the 60 over a 14bff due to the difference in unsprung weight. I forget what the numbers are/were, but bare of brakes the D60 weighed not a lot more than the 8.8 with drums that it was replacing. A bare of brakes 14bff was enough heavier to take it out of consideration. I don't have some HP/Torque monster in the engine bay, I don't have three sets of doublers, and I don't run extreme trails with this truck. If I was going to use it that way it would have a 60 under the front and a 14bff under the rear. My goals for that truck was large disc brakes F&R, and full float. I really despise semi-float axles. It totally amazes me that the flanges don't break off the shafts much more often than they do.

A good friend of mine put a 60/14 combo under his FJ40 with a 400" SBC in it. He told me that the axles were both the best thing and the worst thing that he'd ever done to the truck. Best because he quit exploding Birfields and pinion gears, worst because it dramatically changed the way the vehicle drove.

For the rear brakes on the FSB I went with Expedition rear discs because the Explorer discs won't fit a FF axle (stationary bits want to sit where whirly bits want to spin). The caliper bracket/p-brake backing plate indexed and bolted onto the D60 like they always were intended to work together. Getting the rotor into place took a little more doing, but it wasn't bad. I can point anyone interested to the drawing for that adapter/spacer. The Expi rotors are larger in OD than the Exploder rotors, but the caliper's piston area is only marginally larger. The natural brake bias is close enough with the GM front calipers that little to no p-valve adjustment has been required, I'm running it at max possible rear brakes with no load in the truck and in all but the most extreme panic stop is tracks straight and true.

 

[nvrstuk]

There are a ton of variables and things to consider for sure. I know very little about the 8.8, except it's stout.

My 14 bolt bare housing weighed 10# more than my fabbed 9" bare housing from Ruff Stuff. That was interesting to me when I weighed them on my build thread years ago. I checked earlier today on my build thread and dbl checked the Barnes 14 bolt shave kit that I put on and my measurement showed the 14 bolt only had 1/4" less grd clearance than the 9" RS fabbed housing.

Anyway, the one thing I wanted to add for Lars (and TS) is how easy it is to put dbl splined axles in and then run RCV FF flanges. That's what I had on my "914" housing with the 14 bolt hubs and 9" TruHi 9. I don't FF on my 14 bolt as I don't know more than one guy that's twisted a stock 14 bolt axle off. I didn't have that kind of luck with any Ford 9" axles.

 

[ntsqd]

After having the carrier bearing caps stretch (Mark Williams makes steel replacement caps), and then getting to rebuild again a second time when the R&P got noisy the 8.8 doesn't rate very high in my experience. I had high hopes for it, and those were dashed on the rocks until that ship sunk.

For my own next project rear axle going with Brennan's weld-on flanges and front D44 spindles, hubs, and drive slugs is the most likely option IF I can find a wide enough rear low pinion D44 donor. I've even looked at building it up from a bare casting, but new bare castings DNE.
Otherwise it will be a D60 with 14bff spindles in it, and will use SAI 5x5.5 wheel hubs. I know that 30 spine, and possibly greater, drive slugs are out there for the D44 front hubs.

Interesting, yours is one of the semi-float 14's. I knew that those existed, but I didn't think that they saw much action.

 

[ssray]

May have posted this before….interested in weight savings you can get these. Offerings for Dodge, GM 14b and AAM, Ford Sterling. Kits with hubs in different patterns, Wilwood options for single or dual calipers and bearing and races as well. Savings over 100# per axle. Spendy! Available for the,front as well.

 

[nvrstuk]

I remember looking at that site back when I was building my rear axle.and thinking.... yeah, not for me! lol

Cool stuff for sure tho!

 

[lars]

It's slightly more complicated than @nvrstuk said. So I'll start with a question.

5 lug or 8 lug. This is a really important question that I wish I had answered 20 years ago. But my answer came back 5 lug, which has resulted in significant expense. But I always wanted to be able to share/swap spare tires on the trail. Turns out that doesn't happen as often as it used to.

If the answer is 8 lug, then the answer is the 14 bolt.

If the answer is 5 lug, then more questions. Whose brakes are you going to run? If that answer is Explorer or Wilwood - disc with shoe parking brake, and you are running semi float 35 spline axles...then the Sterling or Dana starts to look better. The last question is driveshaft length/angle. If you are in an EB with a long drive train, then a high pinion starts to come into play. Finally, there is ground clearance.

The Set-20 bearings use 1.562 journals, and accommodate Big Bearing 9 inch brakes. The GM corporate 14 bolt uses 1-9/16 x 30 spline axles. 1.562 is awfully close to 1-9/16. So I don't think they make 14 bolt semi float shafts in SET-20. You kinda want to stay at 1.5 inch x 35 spline. Which defeats a small part of why the 14 bolt is the winner.

If I ignore cost, then I wouldn't know how to answer. I don't know how to do that. Cost is always a factor. But if I could have anything I want...(and I suppose I can...) I always end up with a 35 spline, semi float, 5 lug dana 60 with an ARB. When I'm feeling spendy, I use the Dynatrac pro-rock 60 housing. It's basically a shaved 60 housing with the ground clearance of a 44. But usually I try to find a junkyard 60 from an Econoline 250 Van on 1/2 price day at the pick-n-pull. Then I weld on Billet Torino ends, and throw on some Explorer brakes. Still have to source axles, but that's never not true.

But in your case, I'd just bump up the air pressure on the 9 inch ARB compressor and run it for another 20 years.

Thanks James. I'm in no hurry to go axle shopping, but it's nice to consider options. If I make a move I will happily stay five on 5.5 semi float and stick with the Explorer rear discs that have been serving me well for the last 20 years. I finally have my brakes exactly the way I want them, so that's an easy decision. And yeah, for now my existing assembly isn't giving me any trouble, so I'll keep the pressure cranked up

 

[jamesroney]

Thanks James. I'm in no hurry to go axle shopping, but it's nice to consider options. If I make a move I will happily stay five on 5.5 semi float and stick with the Explorer rear discs that have been serving me well for the last 20 years. I finally have my brakes exactly the way I want them, so that's an easy decision. And yeah, for now my existing assembly isn't giving me any trouble, so I'll keep the pressure cranked up

If you want to torture yourself, and if you can live with a 67 inch wide axle WMS, then the 2004-2006 Dodge SRT-10 Dana 60 has got to be in the mix. It has enormous disc brakes, internal shoe parking brakes, 5x5.5 wheels and 1.5-35 spline c-clip semi float axles. And you can get them for about $600 with factory 4.10 or 4.56 gears. I was giving SERIOUS consideration to running one of these with some offset wheels just to get those brakes.

 

[ntsqd]

From observation much past the max torque of the Explorer discs under an EB is of no real value on the pavement, and will be a problem if you don't dial it out with a p-valve screwed way down. There's a mildly tolerant bias ratio that has to be present or in a panic stop the vehicle will do unkind things.

On the rocks is totally different. There equally sized front & rear brakes are a bonus. A friend of mine just put a lever type p-valve in the dash of his CJ7 so that he can dial the rear brakes down for the pavement and up for the rocks. The lever type lacks the infinite adjustment of the knob type, but offers consistency in settings and speed of change.

 

[michrepairz]

A 30" driveshaft can work without causing vibration if your u-joint angles are properly aligned (under 3 degrees and closely matched). The shorter driveshaft might amplify angle issues, so check pinion and transfer case alignment carefully. Swapping to a full-float 9" axle with Sterling 10.5 outers may reduce weight, but the fabrication effort might not be worth it unless you need specific features. Stick with the Sterling 10.5 unless the 9" offers clear benefits for your build. Prioritize driveline geometry over driveshaft length to avoid vibration.

 

[1sicbronconut]

Dana 60 or 14 bolt is always a debate. I’m with @jamesroney on the selections and why. However I really want a full float 5x5.5 hub on my Dana 60, it is completely not necessary but I want it lol.

As another option that I would do today without a second thought. Super 8.8, they are stout, nearly equal to a Dana 60, and have a much larger wheel bearing, which equals a much larger shaft at the hub, which cures the week link of 35 spline axles with a set 20 bearing, the wheel flange, that is the week spot in that arrangement. Oh and Moser makes axles for them in any bolt pattern you want. Now that being said what I haven’t seen is how strong is the differential, it is wider than a 9” but not much larger in diameter, time will tell.

I've had a few of the super 8.8's apart for various reasons and the shafts are beefy for sure, 34 spline count on them. I don't know how it would play into this conversation but Ford also has a floater version of the 9.75" out as well, other than some pesky outer bolts that control the movement of the the axle shaft in the outer sealed unit bearing.

 

[ntsqd]

What would I find one of those FF 9.75's under?

 

[ssray]

What would I find one of those FF 9.75's under?

I was curious as well….
Some specs

Full floater

Issues

 

[ntsqd]

The idea of a Unit Bearing for a full float rear axle is intriguing. I've looked at the aftermarket options and they get pretty spendy for what I'm wanting to do. An OEM FF using a unit bearing would be great.

It's interesting that the ebay auction says it's a FF, but one of the similar axles linked there says that axle which appears to be identical to the first is semi-float. The center of the flange looks like a SF axle that we're all familiar with.
Looks like the ratio selection for the 9.75 might be limited to the axle that you buy. Filthy had no R&P listings. Neither does Yukon. I'd need 4.27's or 4.30's, so it an interesting option but a no-go for my project.

 

[jamesroney]

The idea of a Unit Bearing for a full float rear axle is intriguing. I've looked at the aftermarket options and they get pretty spendy for what I'm wanting to do. An OEM FF using a unit bearing would be great.

It's interesting that the ebay auction says it's a FF, but one of the similar axles linked there says that axle which appears to be identical to the first is semi-float. The center of the flange looks like a SF axle that we're all familiar with.
Looks like the ratio selection for the 9.75 might be limited to the axle that you buy. Filthy had no R&P listings. Neither does Yukon. I'd need 4.27's or 4.30's, so it an interesting option but a no-go for my project.

Uhm...You might want to research this.

The unit bearing "full float" axle in the F150 with max tow is an enormous pile of crap, and it is the cause of a giant recall, and Ford does not have a solution. The Recall just looks for the broken off bolt laying in the hub cap, and then replaces it with another bolt. I've got a buddy that is in litigation on a lemon law buyback for that POS.

It is not a full float rear axle as we all know it. It is named a 3/4 float, and it is a horrid idea. You don't want one.

The bolt shouldn't be breaking off, and indeed, the bolt as designed is not under any load. But when the unit bearing deflects, (and they ALL eventually do...) then the axle shaft is loaded in bending. Which results in cyclical loading of the shaft, resulting in broken retaining hardware. It really is the dumbest idea ever promoted by cheap, ignorant, and arrogant Tier 1 suppliers to the OEM. These are the same ass-hats that gave you a 28 spline axle shaft and a Dana 30 in the first place. (and aluminum transfer cases, and IFS, etc...)

The idea of a unit bearing in a load carrying axle is asinine. 75 years of failure and futility, and it is still being promoted by incompetent designers. I really don't understand how these Chassis engineers keep their credentials...or their jobs. Run away now. (and yes...Fiat has bought in to the same unit bearing crap for the Wrangler. It appears to be a race to the bottom for Dana-Spicer.

 

[ntsqd]

That particular axle may not be the best design, but I'm not opposed to a unit bearing in concept. I'll leave what they are for others to argue, but in the right application the design is sound. They've proved themselves to be stout enough in some off-road classes and dismal failures in some street applications. Of those failures, who can say that the problem wasn't that the unit bearing was under-designed? It was a sad day when the first finances guy was allowed into the Engineering Design Room.
I flogged the avatar around the deserts of KA for over a decade and it's 'one-step less than a unit bearing' rear wheel bearing design was never a problem.
[EDIT} What I find amazing is that semi-float axles are still built when a unti bearing is clearly a superior design.