Alpine rear axle torque load

[Sunbeam Canada]

What is the maximum amount of torque a stock S-IV/V Alpine rear axle can handle?

 

[alpine_64]

Are you reffering to what an engine will put thruogh it? Or torque as in putting it back together and how much to use?

 

[Sunbeam Canada]

I'm referring to the maximum engine power output the axle can handle.

Now that you have mentioned it. Bolt torque specs would be helpfull also.

 

[SIVAllan]

I'm referring to the maximum engine power output the axle can handle.

Now that you have mentioned it. Bolt torque specs would be helpfull also.

From WSM Rootes Light Car Range (with 1725 Engine)
Torque Loading Figures
Rear Axle
Hypoid bevel pinion nut 110 lbs. ft.
Axle shaft nut 180 lbs. ft.
Crown wheel setscrews 50 lbs. ft.
Differential bearing cap nuts 53 lbs. ft.

This section does not specify car model or Alpine series; looks like they are the same.

Allan

 

[Bill Blue]

Ohan, I don't think anyone really knows the answer. As I remember, Jose says that in order to break his, he needed a very hot 2.8 Ford running slicks, traction bars and several clutch dumps at the drag strip. So it seems it will handle most anything that will be driven on the street.

For most, the biggest problem with Alpine rear axle is the very poor selection of ratios available.

Bill

 

[V6 JOSE]

Bill,

All the monkey business you just mentioned, was done with a Ford 8". When I had the Alpine rear end in my first Alpine, I didn't have a LSD rear end, so had to ease it out of the hole, or it would just wildly spin the right rear wheel. At that time I didn't use slicks either, but the engine was producing about 200 hp. and I power shifted it at 7,000 all the time, which it handled quite well. I drove it like that for about three years, then I abused the spider gears, while doing a burn out at the drags.

I never had any trouble with the axles during all that time, but it seems like someone on the old board posted aomething about some of the rosd race Alpines breaking axles, didn't they? I believe in a well set up Alpine rear end. Mine proved to quite strong, so if you aren't doing some of the crazy things I was doing with my Alpine, I believe they will take anything that even a hot Alpine four cylinder would put out.

Jose

 

[RootesRacer]

I never had any trouble with the axles during all that time, but it seems like someone on the old board posted aomething about some of the rosd race Alpines breaking axles, didn't they? I believe in a well set up Alpine rear end. Mine proved to quite strong, so if you aren't doing some of the crazy things I was doing with my Alpine, I believe they will take anything that even a hot Alpine four cylinder would put out.

Jose

That prolly was me...

Ive seen several road race alpines break an axle, not due to rear wheel torque, or even a clutch dump, but rather fatigue failure starting at the keyway, and crossing clear through the axle, causing total loss of the wheel side of the half shaft. This usually occurs during hard cornering, power has nothing to do with the failure.

The breakage problem is one of a design problem, where the basic design of a tapered axle makes the axle cross section at the keyway the weakest link, and often dangerous. Serious racers build full floating axles, where the wheel is supported by its own bearings, like the front, and not supported at all by the axle itself.

The rootes rear end is pretty strong considering its small ring gear size.

 

[jumpinjan]

...but it seems like someone on the old board posted aomething about some of the rosd race Alpines breaking axles, didn't they?

The weakest part, in my opinion is the cast ring gear carrier and pinion housing. Ian has a rear end that broke the pinion housing in half from a loose ring gear bolt or bolts meshing with the gears, but that's catastrophic destruction.

 

[V6 JOSE]

That's why I said a properly set up rear end. All ring gear bolts tight and hardened axle keys. I do seem to remember the fatigue crack through the keyways now. It is too bad that the factory didn't see fit to put a radius on the Woodruf cutter, when they did the keyways. It would have eliminated the crack caused failures.

Jose

 

[sunbeam74]

Yes, the Alpine axle was known to break. Lots of documentation exist regarding axle failures in racing. Phil Peron was over yeasterday with three axles and a limited slip assembly for the Alpine and we were discussing just that.
Reviewing the axles Phil had.... of course the later rear-ends have beefier axles (wire wheel version).

Phil was wondering if it would be possible to machine off the splined portion of the hub to enable him to use solid disc wheels with the beefier axles.
It looks feasible but I didn't really have a chance to look at the pieces too closely. I wonder if this was Rootes solution with their "competition axles" since they also had "heavy duty" hubs listed as "approved SCCA" components.

The axles which came with the LSD were 10 spline axles to match up with the LSD. Interesting... the housing was stamped with 22705X. The only other marking was a diamond... which may be a DANA symbol.


Steve

 

[RootesRacer]

Yes, the Alpine axle was known to break. Lots of documentation exist regarding axle failures. Phil Peron was over yeasterday with three axles and a limited slip assembly for the Alpine and we were discussing just that.
Reviewing the axles Phil had.... of course the later rear-ends have beefier axles (wire wheel version).

Phil was wondering if it would be possible to machine off the splined portion of the hub to enable him to use solid disc wheels with the beefier axles.
It looks feasible but I didn't really have a chance to look at the pieces too closely. I wonder if this was Rootes solution with their "competition axles" since they also had "heavy duty" hubs listed as "approved SCCA" components.

The axles which came with the LSD were 10 spline axles to match up with the LSD. Interesting... the housing was stamped with 22705X. The only other marking was a diamond... which may be a DANA symbol.


Steve

Photos please?

 

[sunbeam74]

Jarrid,

Can you e-mail me at work - I tried e-mailing you about something else and I guess I didn't save your new e-mail address.

Unfortuantely, I can't do the upload and posting thing from work otherwise I would post them. Maybe late tonight.

milano164@comcast.netXXX


Thanks,,


Steve

 

[Nickodell]

That's why I said a properly set up rear end. All ring gear bolts tight and hardened axle keys. I do seem to remember the fatigue crack through the keyways now. It is too bad that the factory didn't see fit to put a radius on the Woodruf cutter, when they did the keyways. It would have eliminated the crack caused failures.

Jose

Same thing happened to the rear axle of my Allard. When the car was made, Sidney Allard used as many stock Ford V8 parts as possible, including engine, transmission and rear end. They reduced the rear track by cutting the half-shafts shorter and remachining the taper and Woodruff keyways. And they, too, made the corners sharp instead of radiusing. Sure enough, one day the right rear taper broke in the hub, and hub and wheel parted company. By great good luck it happened as I was cornering at about 20mph, the first thing we knew being when we saw the wheel spinning past us and found ourselves grinding along on the brake backplate. Ten minutes earlier we had been doing 80.

I took the broken end to a metallurgist at work, and he immediately diagnosed metal fatigue. He showed me what they call "beach lines" radiating out from the corner where the fatigue had started like ripples, and said that from the moment the car was first driven, it was a mathematical certainty that it would fail after x million rotations.

 

[sunbeam74]

Axle photos

Here are some of the axle photos:

Alpine LSD...

Alpine axle with 10 splines

The wire wheel axle is only a millimeter or two larger but the taper is significantly bigger.

Starting from the top,

1) 10 Spline axle with taper to match the early disc wheel hubs

2) Stock early axle for disc wheels

3) Late wire wheel axle - beefier