Rear Axle Housing: Opinions?

[nvrstuk]

Excellent info Paul (as always)

Disadvantage of the Set 20 brgs is the axle seal can only be replaced if the brg is pressed off the axle itself. Usually this results in messing up the brg so you get to buy new brgs, new seals and then if you don't have a press pay to have them pressed on.

With the stock brg setup for an EB the seal fits into the housing and then you install the axle into the housing. So you can replace either w/o being forced to replace the other.

Both of these have a common safety disadvantage-

Besides the obvious "beef and toughness" (huge R & P, and axle housings that don't bend) advantage of the 14 bolt is the huge SAFTEY issue of the FF design of the 14 bolt. The axle on the 14 bolt does not rely on a simple "tension fit" pressed on bearing to hold the axle in place. When a stock drum brake 9" axle bearing fails on an EB the axle either breaks where the brg mounts due to heat build up or more commonly the bearing heats up due to the housing being bent and the axle can then "walk out" of the housing and your tire/wheel and axle pass you by as your driving along on your bumper or leaf spring bolts. So common it's spooky. We used to buy EB's that were towed to town off I90 often rolled because the rear axle came out due to simple brg failure. My buddy bought 4, all rear axle failures.

The 14 bolt FF axle prevents all that. I had it happen so many times I won't run a 9" axle in a 4x4 environment unless it's a FF. The housings are too lightweight w/o trussing to prevent bending and then ultimately having your tire come out beyond your fender.

Edit: Schreiner Enterprises still sells FF kits for 9" housings relatively cheaply.

 

[nvrstuk]

I stand corrected, Schreiner Enterprises, thanks Old Timer.
Here ya go
http://www.9inchfloater.com/

 

[Wrightracing]

I have not ruled out a 1 ton for axle. When I put the 9in Currie in, I put it in along in the driveway. I helped a friend put a 14 Bolt in his Blazer and it was significantly heavier. I think the OEM brake Drums were the extra weight compared to the 9" drum brakes.

So what is the widest full floater? I am looking for something between 68" wms to wms and 72" I know the Econoline van 9" is 68" I think in 1978 to 1986.

I could sell my semi floater Currie 9" 65" wide for around $2k. Then I thought about getting a 2005 Superduty 1 ton rear axle. I am just a bit skeptical about the unit bearings being as strong as the 1980-1997 1 ton full floater with the snout welded to the housing tube's.

So many options and I just saw a uncut 74" wide fabricated Wicked Creations 9" 3.5" tube's and a back truss, for $1200. I would put Dana 60 snouts and center the diff to run equal length axles, so I could carry one spare axle.

Ugh.

David

 

[nvrstuk]

Million choices huh??
Look at pinion length & pinion support btw D60 and 14 bolt.

In my build thread I listed the advantages of the 14 bolt over the D60, over the 9" (easy), over the Sterling.
Your choice but 14 bolt stock (also already a FF) is going to be extremely hard to grenade.
Pinion length reduces angularity and people don't take that into account when designing and laying out geometry of rotating parts and lifespan of those parts. Just a couple thoughts

Great discussions here on CB.

 

[markw]

I’m building a new EB race truck to run in the NORRA Pioneer Class. Stock width axles and no FF are dictated. Also front axle required to be stock for the year so D44. My last race Bronco had (has) Camburg FF and Currie D44 HP. Unfortunately I can’t use them in Pioneer.
So she’s got a WH 9” with Waveloc and 35 spline chromo and large knuckle, Reid Racing and RCV axles in front. Pretty sure desert racing is not as hard on axles as rock crawling. Unsprung weight is certainly a factor. I’m limited to 2” non bypass shocks so minimizing weight is huge.


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[toddz69]

I’m building a new EB race truck to run in the NORRA Pioneer Class. Stock width axles and no FF are dictated. Also front axle required to be stock for the year so D44. My last race Bronco had (has) Camburg FF and Currie D44 HP. Unfortunately I can’t use them in Pioneer.
So she’s got a WH 9” with Waveloc and 35 spline chromo and large knuckle, Reid Racing and RCV axles in front. Pretty sure desert racing is not as hard on axles as rock crawling. Unsprung weight is certainly a factor. I’m limited to 2” non bypass shocks so minimizing weight is huge.


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That'll be plenty beefy for Pioneer!

Todd Z.

 

[Broncobowsher]

I still find it amazing that thousands of Broncos have been upgraded to 31 spline axles, gears, lockers, big motors for decades. Most of them have no issues. But this thread says that anything shy of a full floating 1-ton axle is going to fail on the way out of the driveway.

Most of us don't have a reputation for blowing up every piece of driveline ever created. Nor are we trying to make full race trucks.

I'm still going to say that 31 spline semi floating axles are still good for the majority of the Broncos being modified.

 

[Wrightracing]

I still find it amazing that thousands of Broncos have been upgraded to 31 spline axles, gears, lockers, big motors for decades. Most of them have no issues. But this thread says that anything shy of a full floating 1-ton axle is going to fail on the way out of the driveway.

Most of us don't have a reputation for blowing up every piece of driveline ever created. Nor are we trying to make full race trucks.

I'm still going to say that 31 spline semi floating axles are still good for the majority of the Broncos being modified.

I tend to agree with you. I ran my Currie 9" for 20+ year's with 31 spline axles, 4.10 gears and a Detroit Locker. That was in a 1986 Full-size Bronco with under 300hp and running 35x12.50x15 tires. Most people will be in that situation and it will work well.

Now in my case, I am pushing the horse power into the 550hp range with 37in tires and approximately 20 inches of wheel travel front and back. I will be running a Detroit Locker, 5.14 gears an going 3 inches wider per side. The Bronco will be a toy and driven hard, so I would rather sell my current 65" wide, 9" and get something that is more suited for my application.

Love going fast in Baja and the dunes. I tend to be a frequent flyer in the dunes

David

 

[nvrstuk]

I never grenaded D20 output shafts, 31 spline rear axles, TruHi9 rear ends, 35 spline ARB cases, 4 D20 cases UNTIL I started running doublers, low 6:1 first gears X2 with doublers, 100% locked frt rear, and tall tires!

90% of this carnage was all below 1,200rpm idling and BANG- splines twist off, BANG- gear teeth stripprd off in the D20 clusters, Bang-output shafts. I think you all get the point.lol

It's not HP & it's not driving like I do in snow & sand. It's torque THROUGH the drivetrain and that torque applied to high traction surfaces. Dirt, mud, hi-speed racing are all 100% different (except for shock load).

Like Todd said, you'll be gold for that type of application!
Have fun!

 

[Yeller]

For high speed off road use I always found the pinion shaft to be the weak link in a 9”. Found it could be twisted off quite readily with 500hp and 70mph through small whoops. Wasn’t till we went to 35 spline pinion that we got a solid, reliable 9”.

I do agree for most, 31 spline is adequate, many of us in this thread don’t fit into the “most” category

 

[markw]

OP what are you going to do?


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[nvrstuk]

OP what are you going to do?


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Inquiring minds want to know!!