Full floater.... but better? FF axle flanges.

[lcwizard]

It's not that the chromoly isn't very strong, it's just that in a semi float situation it will probably have a shorter lifespan than a stock axle unless you are running tons of power that exceed the torque threshold
of the stock axle. Where the stock shaft will succumb to twisting loads the moly will succumb to bending and fatigue from the pounding cycles the road introduces through direct bearing contact. I'm perfectly comfortable with the stock shafts. I've only broke one as opposed to 15 or so birfields. Then again the highest horsepower I run is a TBI350. If I feel I can't live without 300+ HP in front of 40" swampers
I'll probably build something with 35 spline axles.
I like the floaters because I think you can get a marginal strength advantage but mostly the ease of
maintenance, especially on the trail.
The last semi float I broke on the trail was an all day affair since I didn't have a spare with me.
With a floater, just pull the shaft and drive home

 

[ntsqd]

A semi-float axle shaft is, at best, a horrid compromise in design. The very design has a huge red arrow pointing at where the wheel bearing fits on the shaft that says "Break Here!" There are bending loads and twisting loads right where the shaft makes a HUGE change in cross-section and is simultaneously rigidly supported by the bearing at the same location as the change in cross-section.

That's all for a non C-Clip axle. When the C-clip's set of additional design "features" is added to the equation it is a wonder that they work at all. All C-Clip axles that I'm aware of work the same way, there is no inner bearing race. The wheel bearing's rollers ride directly on the axle shaft. For that to work and last the surface of the axle shaft needs to match the hardness of the rollers.
Gee, what a great idea! Let's take a design that is severely compromised already and now take the very area where the first failure mode is very likely to be and harden the surface of it. It's a wonder that the bloody things work at all!

On the OE FF axle housing, I'm unclear on the factory's intent with that puny little outer seal. None of the domestic FF axles employ a seal there and they all seem to work fine. The difference is that in the domestic axles wheel bearing lubrication is done with diff lube rather than grease. The only reason that I've been able to come up with for having that seal is the speculation that perhaps the OE fill plug level may not result in a lube level that is high enough to adequately lubricate the wheel bearings. At some point when I get around to rearranging my Toyota FF housing to be a centered diff I plan to look into this and make whatever mods might be needed so that the wheel bearings run in diff lube rather than grease.

 

[CruisinFJ60]

Even if they do properly heat treat them moly is a much better choice for a full floater. Although it has a higher tensile strength than say 1541h, it is too brittle to be used in semi floaters. Moly will perform well,
taking higher torque loads but at the cost of a shorter life span. I ran a couple sets in the 80's on an HDRA
pre run truck ( against the recommendations of Summers Bros, the axle builder) At about three years average life they all broke, always at the bearing race.

Mine broke in the middle of the short shaft. The "bad batch" was supposedly just in the 60 series long side and was supposedly just a improperly hardened bearing surface (mine showed signs of this after 500 miles) but I broke the short side, the one side that supposedly never had any issues.

 

[lcwizard]

I did hear of the bad heat treat situation. That would definitely pose a problem. I never had an issue withe the bearing surface of the Summers Bros axles I had built it was the work hardening that occured.
Both shafts broke in the middle of the race within months of each other. They did last about three years
and Summers gave me free replacements. Like I said I believe semi floaters, built correctly, will provide good service but when an axle breaks on the trail ( both floaters and semi floats will break ) , I'd rather it be a full floater.

 

[Kynot62]

Got to agree with you about FF on the trail. When I broke a drivers side shaft at Rubicon, my rig was still rolling. While I didn't have a spare (I carry them now) all I had to do was pull the big part of the shaft out and put the remains of the flange back on to keep the oil in and I was moving again.

Can't imagine that with a semi-float

Tony

 

[slowandsteady BJ]

The last semi float I broke on the trail was an all day affair since I didn't have a spare with me.
With a floater, just pull the shaft and drive home

No kidding,

First one I broke cracked the carrier bearing and warped the ARB carrier = $$$$

Second and third explosion (both shafts) nearly ruined my Whipsaw Trail run. Thank goodness I had a friend that drove for a whole day to get me another set (from a great Mudder I haden't even met). While I spent a day cleaning shrapnel and wrenching on a mountain fighting mosquitoes.

I look back and laugh now but at the time there was little laughing! Im done with semi's and C-clips.

This Ruff Stuff "kit" with the custom "Bobbys" is the way I'm going for sure!


EDIT
Also: Big thanks to the Costal Cruisers for saving my A** that day! And my pit crew, dogs included. That was a heck of a day(s)....

 

[baxter650]

ntsqd... At some point when I get around to rearranging my Toyota FF housing to be a centered diff I plan to look into this and make whatever mods might be needed so that the wheel bearings run in diff lube rather than grease.
.
In the late 80s i made a 9''/Toyota hybrid axle for my PU.
I eliminated the axle seal and lubed the wheel bearings with the diff lube.
I drilled and installed a diff plug in the carrier, higher than the original fill level.
Just have to make sure that the Grease seal surface on the bearing hub you are using is in good shape.
I used one that was worn and that side leaked a bit.
Had Strange Eng. make my 31/30 spline axle shafts and used Toyota blanks, make sure to seal the dust cap as it will leak too.
Drove the truck as my DD for a few years with no issues.

 

[ntsqd]

Thanks Baxter. My partially formed and completely un-investigated plan at the moment is to use FJ80 drive flanges with doubly splined shafts. I have the flanges, but don't yet have the dust caps.
With the current OE FF I'm trying out using Hylomar between the drive axles and the wheel hubs. I've used it in other, difficult to seal locations where RTV was very definitely the wrong choice too. So far about 400 miles and a year of sitting with no leaks.

 

[lcwizard]

the problem with using stock drive flanges is that the fit is too loose . When I was into HDRA/SCORE
builds a lot of trucks were using double splines with a drive plate. The key to longevity was to have a
tight press fit. A lot of the time it involved heating the flange and soaking the axle shaft in dry ice in
acetone. If you want to be super cool see if someone will build you 17-4 stainless shafts. It makes
moly and 300m look pale

 

[ntsqd]

If the splines were dry I can see the wear potential with a loose fit. Presumably anyone with a good rep for making axles can make those splines a suitable hardness for best wear life. Otherwise if they can cut splines then I'd guess that they can cut them to be a tight fit in the stock flanges. I had exactly that done for a work project. We had the male splines cut to be a very tight, but sliding fit (smack dab in the middle of an LT class fit) in the existing female splines by a local guy. He did a fabulous job, could hear the air escaping in a dry test assembly.
Not too familiar with 17-4 in a reversing torsion application, but have used at least 100 lbs of H900 condition for various small high pressure fittings and high wear/strength demand hardware. Wonderful stuff, just don't put it in a saline and cold environment as it fails spectacularly there.

For my own use I suspect that one of the HSLA's commonly used to make axles and half-shafts is more than suitable to twist 33's in an over-landing type of use. The cost and strength of any of the 4xxx series, not to mention the short fatigue life, really aren't warranted in my use. A guy twisting 40's in a comp or hard core rock application would be a different story.

 

[lcwizard]

<quote>. Wonderful stuff, just don't put it in a saline and cold environment as it fails spectacularly there.

so what you're saying is if you use 17-4 , don't drive in into Prudhoe Bay while hunting fur seals... damn there goes next years summer vacation.
It sure makes a pretty axle...but apparently a poor choice for a whaling harpoon

 

[FL cruiser]

The Ruffstuff ends and FF setup is tempting.
There's still some $$ to be spent by the time the rear end is complete.
Ends $200, Custom axles $400, another set of axles for spares $400, plus the hardware, calipers, hubs and rotors.
Really not that bad in comparison to building any other type of rear end.

The ends should still be aligned and should probably be welded While a centering bar is in the rear. At least for a highway driven rig that will see lots of miles. See pic below. Having a centering bar with discs made can add some cost too.

I wish I would have started this way(FF), started with a centered diff, center output transfer etc. But like others, I have a crapload of money spent on my rigs' existing setup and am spent out! The weak link on my rig is the rear axles. I bought Poly Performance axles a couple of years ago. I'm on the third set. Never broke a PP axle yet, but they wear out where the bearing rides. Went back to stock and am breaking axles again. Kind of fed up.

The FF is a superior design, but I'm looking making some kind of cheap improvement to hold me over a couple of years until I can afford to build another trail rig.

In another month I think I'll investigate putting Ford housing ends on and getting the PP axles (and a couple of stocker axles for spares) machined down so Ford bearings can be pressed on. I already have a Ford centering bar.
Not the ultimate solution, but has to be better than wearing out axles every single 2,000 mile road trip.

 

[baxter650]

the problem with using stock drive flanges is that the fit is too loose . When I was into HDRA/SCORE
builds a lot of trucks were using double splines with a drive plate. The key to longevity was to have a
tight press fit. A lot of the time it involved heating the flange and soaking the axle shaft in dry ice in
acetone. If you want to be super cool see if someone will build you 17-4 stainless shafts. It makes
moly and 300m look pale

Are you saying that you were having failures due to lose spline fit?
If so , over how long a period?

 

[Elbert]

what about this at ruff stuff...anyone run one of these yet?

Axle Flange, Rear, Toyota, Full Float - RuffStuff Specialties

 

[CruisinFJ60]

I wish I would have started this way(FF), started with a centered diff, center output transfer etc. But like others, I have a crapload of money spent on my rigs' existing setup and am spent out! The weak link on my rig is the rear axles. I bought Poly Performance axles a couple of years ago. I'm on the third set. Never broke a PP axle yet, but they wear out where the bearing rides. Went back to stock and am breaking axles again. Kind of fed up.

The FF is a superior design, but I'm looking making some kind of cheap improvement to hold me over a couple of years until I can afford to build another trail rig.

Not the ultimate solution, but has to be better than wearing out axles every single 2,000 mile road trip.

http://www.currieenterprises.com/cestore/images/product//currie/ce99050.jpg

The reason those axles were wearing out in a meer 2k miles is because they were and still are CRAP poly rear cruiser axles are junk dont buy them. If the bearing surface was properly hardened they would not wear out so fast.

 

[lcwizard]

FL cruiser's Avatar

Join Date: Jul 2004
Location: St Petersburg, Florida
Posts: 927
Garage

<quote> The Ruffstuff ends and FF setup is tempting.
There's still some $$ to be spent by the time the rear end is complete.


Here's the difference..
The flanges I've built are self aligning. I'm using Toyota's machined ends to align the flange. One downfall is you are stuck with a fixed width. 59 1/8 if you use a 40 housing or 61 1/8" with a 60 housing. I will post up pics tomorrow of the assembly so there is a better understanding.

 

[slowandsteady BJ]

what about this at ruff stuff...anyone run one of these yet?

Axle Flange, Rear, Toyota, Full Float - RuffStuff Specialties

Are you kidding me?

 

[lovetoski]

I will post up pics tomorrow of the assembly so there is a better understanding.

Looking forward to it.

Also, since I'm driving a mildly built 60, and am interested in having a locked but beefy rear axle (have SF + lockright currently) would be interested in how to mod a stock rear SF w/out major overall modifications (if possible).

 

[Elbert]

Are you kidding me?

Yea...sorry.. I see now, that this was the initial question.

Looking forward to see what makes this work.

 

[CruisinFJ60]

Looking forward to it.

Also, since I'm driving a mildly built 60, and am interested in having a locked but beefy rear axle (have SF + lockright currently) would be interested in how to mod a stock rear SF w/out major overall modifications (if possible).