If you have the appropriate Axle Shaft Matched to the Bearing Set20 (3.15 x 1.562) or Sealed Bearing (3.150 x 1.531) will they Seat in either axle Flange Big Old or Big New (Torino). Brake register will not be an Issue. Knowing on the Set 20 leaving out inner Seal because it has it's on Sealing Surface and needs Differential Lube. I've Test fit Both and there seems to be no Difference. Am I missing something? Thanks

 

All the axles that used Set20 bearings that I have seen were not machined inside for the inner seal. That tells me that there must be some difference but I have never tried to actually swap them.

 

Got Ya, I am welding on Flanges after a Little more research, they are Machining Flange's for inner Seal using the sealed Bearings for the Torino Style. But you are correct the Factory Flange is not Machined, I looked past that, Thank you

 

Correct. No difference between regular large bearing and Set-20 setups as far as the inner bearing surface goes. They interchange and that's what Ford did when they upgraded the bearings. They did not change the housing ends, but they did change the bearing retainer/cover (not the inner retaining collar, though they changed that too) to retain the axle in the housing and put the correct minimal preload on the tapered bearing setup.

The axle shafts were different, so you could not retrofit one bearing type for the other as far as the axle shaft itself was concerned, but for the housing, no trouble other than making sure you have the right bolt size. Some were 3/8" holes and some were 1/2" holes in the housing end.

I'm sure there is other stuff that ford came up with during that time, but as far as what we've been doing for years, all that info above holds true.

paul

 

I prefer the older Bearing set, Sealed that is, over the set 20. To busy for me and double the Seal area to Fail. And you have to Depend on axle Lube. And if its using axle Lube to me means its getting Differential wash to the Bearings, and or water. maybe nothing but I am **** that way. The Housing I am using from a 77 F100 cut down 4" (to eliminate Neck Down, 3 1/4" all the way to Flange now) has Torino ends with set20 bearings and no Machined surface for and Inner Seal .Some of the After Market's are making Torino Style Flange ends for the Inner Seal so I can run a Sealed Set. .031 thousandths difference on the Axle surface which I'm changing Lug pattern anyway, Both 1.562 ( Set 20 Axle)and 1.531 (inner Seal Axle) are readily available Cut to fit 31 Spline. Eaton Tru-trac, Solid Sleeve Daytona with 3.50 gears behind my 351w C-6 ought to getter done. Thanks for the reply's.

 

I prefer the sealed bearings as well. As you said, too busy and too many chances for a leak.
Especially when retrofitting into an older housing where the outer seal surface might already have nicks and scratches in it.

I usually recommend silicone sealer around the perimeter if retrofitting to an older end.
New ends are the way to go.

In the small Broncos we don’t really need the extra strength of the set 20 because most people never break a regular bearing and they typically last 80 to 120,000 miles even under pretty hard use.
I don’t think sharing the lube with the differential has ever proven to be much of a problem though, as the tapered bearings typically last well longer than the seal can keep the oil inside.
The leaky seal at 90-100,000 miles usually means it’s time to replace the whole thing anyway.
You can still find some suppliers that stock the seal and race only, but most places are going to sell you the whole assembly anyway.

yours sounds like it’s a pretty nice set up. Have fun!

 

I'm bad to keep old Bearings and Seals for Reference, I've removed Set 20's and Sealed bearings 35 to 50 years old, Soak them in a caustic Solution Bath for and Hour or so and Clean them up for Inspection. Every Sealed Bearing Set I've tested that came from a Closed Housing that has never been Cracked open will be smother than the Set 20's I have inspected, that's how I got to my Opinion.

 

I think it's handy to check all the old stuff. I've probably kept more than I've tossed, just to either check them out or use them as trail spares if good.
But we have come to one conclusion at least as far as the '66 to '77 Broncos are concerned, whether big bearing or small, you need to figure on changing the stock sealed ball bearings before 120k miles no matter what condition they seem to be in.

In fact I tell other owners that if they're doing any diff work that requires them to remove the axle shafts from their 9" to just go ahead and replace the bearings if they have more than 75k miles on them. If they have 100k then plan on doing it even if you're not in there for other reasons. And if you have 120k or more, getting it done becomes THE priority.
I assume not all vehicles with Ford 9" rear ends have the same history, but it's far too common on the old Broncos to actually have one fail under load when mileage is approaching 120k to ignore. Far too consistent...

Unfortunately over the years I have not kept strict track of which ones were large and which ones were small, but the overall consistencies were hard to ignore.
1. Almost all were at or over 100k. With the really bad ones right about 120-125k
2. Almost all were either at highway speeds, or towing a load. Or both.
3. Almost all of them were not abused (or was not known) and never gave a hint or clue that they were failing until the rear wheel came off and tried to pass them on the highway!
4. Almost all of the few that did not happen to be at speed or under load when the failure occurred happened at slow speed (one in a parking lot) but within a few days right after finishing a long trip or loaded down for a weekend's work or play.
So the "assumption" on my part is that higher speeds and higher loads make things hotter, and just generally stress them more. Enough to get them to the point that they fail catastrophically if let go too far.
Again, most of the bad ones at a point just near or over 120k miles, with at least some few at just over 100k miles.

My own were the big bearing and while they were toast at less than 90k miles, they probably would not have actually failed until later. Just glad I never waited to find out.
Everything drove fine, but when I had the brake drums off to inspect the brakes I thought the passenger side bearing seemed a little loose and "dry" sounding. I knew nothing about these bearings specifically, but that did not seem right to me. Having only worked on adjustable tapered roller bearings, I'd never had a chance to experience a bad wheel bearing up to that point. Only knew the basics...
Changed them both and was amazed at the difference in what I did not know was wrong! Not only was were my trips now quieter overall, but the vehicle rolled so much easier than before. I think some truck tires can make so much noise they mask the subtle hum and grind of an old bearing.
Lesson learned.

Anyway, long winded way of saying not to take bearings for granted as being "lifetime" parts. And to watch your rear!

Paul

 

100k with as many vehicles as I have, would take me probably 300 years, Hover Craft should be the Flavor of Day, good info and good conversation and advise, nothing substitutes good Maintenance keeping Check on things, Thanks

 

Haha! Yeah I hear you on the mileage limit. I have more cars than I need right now and even daily driving them will never add up to the old days.
not that I’m complaining right now! Spent way too much time in the saddle and too little walking and running. I’m trying to get my legs strong again.

And at six bucks a gallon, for once I have good timing.

 

That's why I bought a KIA, I have all my Ford Toys, but rounding and abouting is done in the little 35mpg Disposable car.

 

Yep, sounds a good plan. When I was younger I did that with motorcycles. They already performed well but got 40-50mpg (or 201mpg if you include my Trail-90!) and I could go a long way on a buck.
With all the distracted drivers these days, along with the crazier-than-ever motorcycle riders, my motorcycling days might be passed. I may just go with a KIA too!

Paul