I was talking axles with a couple buddies from work. The subject of the Sterling, D70, and GM 14 bolt. All three are stout and capable of handling big tires and a lot of abuse. For some reason the Sterling is regarded as the weakest of the bunch. I have read this in several magazine articles that say the same. It's seems anything that Ford puts out gets negative feedback. I am very familiar with the ins and outs of all 3 of them. So what's so bad about the Sterling?

 

Absolutely nothing. The "issues" those magazine articles like to say they have are mostly non issues. Consider that every 87+ SRW F250/350 has one in it, if they were such a bad axle Ford would have done something different by now.
Stock to stock the Sterling has better shafts than the other two. The o-ring flange seal is a much better design, outboard brakes which the other two didn't have until later.
They should have the tubes welded to the center, and the stock axle flange bolts like to back off when welded/spooled. I have mine set up with studs and cone washers in my wheeling rig, my F350 came to me with lock washers on it.

 

That's exactly how I feel about it too. Ditch the crush collar on the pinion, and throw a solid spacer kit in there. Do that and the axle stud mod like you said, then they're pretty much bulletproof. Everyone I talk to raves about the GM 14 bolt, and supposedly how they are the best blah blah blah. I've built (rebuilt, regeared, etc) a couple of them, I will admit they are very stout. As I see it the 14 has basically two advantages over the Sterling. Setup is super fast and easy, and the pinion design. On the flip side, they are just as heavy (if not heavier than a Sterling), the selection of lockers and limited slips is very slim. The ground clearance is horrible, poor hub design (IMO), smaller 30 spline axles. "Oh but you can get it with a locker from the factory!" They'll tell me. My reply back with two thumbs up, "Oh yeah G80 Gov Lock, those things are great". If you're lucky enough to find one out of a CUCV, you'll get one with 4.56s and a Detroit Locker. I haven't priced one, but I would be willing to bet you would pay a premium for a 14 bolt out of one of those trucks. Kind of a laughable matter IMO, I bought a Sterling from a guy who was running it in his Jeep. He let it go super cheap, he was swapping it out for a 14. He actually thought he was going to gain a ton of strength, smh. Oh well, some people are just ignorant. Of course he was also the classic Chevy/Jeep guy... go figure.

 

There's nothing wrong with it. The only one that isn't great is a short spline pinion. The 10.5, 14 bolt, and Dana 70 are pretty close in strength. I prefer the 14 bolt. It has the 3rd pinion bearing, drop out pinion, screw in adjusters, just so much easier to work on. Down side is it's a pig, you need to shave it. I like the 10.5, no carrier break to worry about, left and right threaded axle nuts, o ring axles, gear selection does suck. I like the d70 the least by far. None of them are bad axles and I would run any one of them and never swap one for the other two, If you are breaking, you need to go bigger.

 

Gear selection in the 10.25 matches a HP60, so that point is moot. Deepest is 5.38, same as a 14b. There were Ford 7.17's at one point, but those are made of unobtanium now.

 

If there is a need for a ratio deeper than 5.38, you are probably pushing the limits of a 1 ton axle anyway. Might as well make the next step up, to some big boy axles Rockwells or better yet portal Mogs. Regarding choices for the 14 bolt, the last one I rebuilt for a guy. He had me looking into lockers and limited slip differentials, the choices are not nearly as abundant as they are for the Sterling.

 

 

I've heard their main weak link is the chance of slipping the tubes in the center section, and that welding isn't a good fix for some reason. I think it was that it was more prone to cracking then? Maybe the tubes and center section are different materials that don't play well together? Anyway, that's what "I've heard" so take it for what it's worth.