Front CV axle failure

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therieldeal

New member
is this a common failure point for the alltrac front axles, or a freak incident?

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i am running them in a FWD configuration (1MZFE camry trans, MR2 stubs, alltrac axles) on a FWD car (its a ford escort... long story) with about 350 whp.

i got a little wheel hop this weekend in 2nd gear on a highway on-ramp and destroyed this axle. it was an OE toyota axle. i am ordering a GSP lifetime warranty axle to replace it... but man it'd suck if this is common lol. i just upgraded the whole drivetrain of this car to eliminate the weak mazda gearbox that kept exploding on me... 3k miles later i lose an axle, on the street no less!
 
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therieldeal

New member
Yeah... wheel hop sucks. I am re-upgrading the control arm bushings in hopes of reducing wheel hop. I already have poly energy-suspension bushings in there, but I located some even stiffer bushings from another source. My engine/trans mounts are already about as stiff as they can get without going solid metal.

If this is more than just a freak incident its going to be a pain in the ass. By failing where it did, all those axle shards were forced into my wheel bearing which probably should be replaced again... only 3k miles on it :(. Does anyone know of any upgraded axles for the alltrac?

I am thinking I might be able to use MR2 axles if the length is correct, I'd just need to make some custom hubs. The hub splines are larger in diameter, less of a weak point.

This car does not have good luck with drivetrain components... so far the story goes:

200-275 hp w/ stock drivetrain:
Broken stock axle, failed CV joint (replaced)
Ran 12.61
Broken stock diff after ~10k miles

275-320 hp w/ rebuilt mazda drivetrain (new axles, Quaife LSD, rebuilt low-mile trans):
Ran 12.28
Stripped 3rd gear after 3k miles

~350 hp w/ Toyota drivetrain (adapter plate to retain mazda engine):
Ran 11.87
Broken axle after 3k miles
 
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Simba

New member
Never seen that before, even with wheel hop and considerably higher power levels.

I would suspect bad axle nut torque or some other kind of pre-existing damage to the shaft.
 
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therieldeal

New member
Axle nut torque was correct (set with a torque wrench to toyota's spec), and I'm using brand new OE Toyota nuts w/ castle retainers. The hub depth and all related diameters are identical between the Escort and Celica (oddly enough), so everything lines up perfectly with these axles in my stock spindles.

Previous damage or a factory defect is a possibility I suppose. I did purchase the axle used, however it was in good shape with no visible flaws. It is an OE piece, from a stock ST185 which was rear ended & totaled.

My concern is that the axle shaft itself is thicker than the splined end where it failed. Any/all shock loads will be focused at this spot since it is clearly the weak point. With this smaller diameter section being very short in length, it makes sense that it shattered here when over-stressed.

In comparison, on my stock escort axles the axle shaft is slightly thinner than the splined end. Being a much longer "weak point", my thinking is that it may have some give/twist to it which is capable of absorbing some shock loads without failing.

Does this make sense or am I talking crazy? :)
 
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Simba

New member
therieldeal":3nii95uk said:
It is an OE piece, from a stock ST185 which was rear ended & totaled.
Click to expand...

I would say that if the donor car was hit hard enough to total it, there's your reason. If the shaft were loaded while receiving a significant axial impact (say, an impact to the wheel) it could have weakened the metal without any obvious visual indications.

Generally when Toyota CVs fail (as happens on very high HP Supras, etc), it's the joint itself that fails, not the shaft or spline components.
 
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therieldeal

New member
the car was parked in the street with no one in it, rear ended by a drunk driver in the middle of the night. no damage to anything aside from the squashed trunk and tweaked chassis. front wheels were fine, not a scratch. a friend of mine bought the rear diff & axles out of that same car, and hasnt had any issues with those parts afaik. i guess however unlikely, it is possible the impact could have damaged something though.

i'm glad to hear that this isn't something you guys have seen before. hopefully its something i wont encounter again. when it first broke i assumed it was the inner CV, and i cursed myself for not upgrading the cages and bearings right away. those are the only failures i had seen during my research, which was mainly on MR2OC.
 
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therieldeal

New member
Odd... now THAT looks like the kind of failure I'd expect with an over-tightened axle nut. The drive splines are still intact... in theory he should have still been able to put power to the ground, at least until the bearing/hub walked itself out =x.
 
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Mafix

New member
i could write a book on the places i've busted cv joints.
i've snapped shafts (pick a place)
i've broken cages
i've sheared the 6 bolts
i've twisted the inner shafts off
i've ripped boots to shreads (usually compounded with one of the above issues)
i've shot axles literally out of the car (not fun at high speeds)

hence my current toyota cluster f*ck drive train setup. 20 years of technology all mixed up under one hood. and now that i re-read all that it sure seems that i'm an idiot on install but i swear it's not me. my car likes to eat things; like axles, transmissions, my wallet, my sanity, ect. :crazy:
 
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