Outer Limits 4x4 Board

re the arb test

The Toyota axle failed at 6,929 ft-lbs.

The Chinese locker failed at 6,412 ft-lbs.

Pretty close. You could say that if your Toyota puts more than 6,000 ft-lbs through the drive train you will be breaking something whatever you put in it.

Does anyone know what sort of ft-lbs a Toyota, and especially a Sierra, can generate in the real world (not a test bed)?

It is a pity ARB are so extortionately expensive. They are a good product, but with no competition on the airlocker, they can charge whatever they want, and do exactly that.

steve125 wrote:re the arb test

The Toyota axle failed at 6,929 ft-lbs.

The Chinese locker failed at 6,412 ft-lbs.

Pretty close. You could say that if your Toyota puts more than 6,000 ft-lbs through the drive train you will be breaking something whatever you put in it.

Does anyone know what sort of ft-lbs a Toyota, and especially a Sierra, can generate in the real world (not a test bed)?

This is a little off topic now, but I'll respond to this. I'm not having a go at James' idea to bring in some cheap lockers - if the market is interested, then they'll sell. There's always a market for a cheap product.

Personally, I wouldn't run copy airlockers, not at upwards of 60% of the cost of the real thing, but maybe that's just me However, I'm not the market for these parts. The questions raised in the post above are more generic that the issues in this thread.

A) There's no way I'd want a locker to break before an axle. It's relatively easy to change an axle, even on the trail. Axles are in wreckers. Axles can be upgraded. A locker can't. Axles are a better weak link than a locker, especially an expensive and relatively complex locker (as opposed, say, to a lock wrong or a mini spool). A properly smashed locker and you're on a trailer home. I drove 60km home after breaking my last rear, semifloating axle ( I'm not advocating it, but I do do all my own stunts) with a USD$109 TT mini spool in the back. The spool didn't care a bit about the little chunks of axle swimming about, or the flopping about axle end chewing up the preload adjuster. We've changed front axles in minutes.

B) 6900lb/f - pfft! that's nothing. My Sierra can generate somewhere over 10000 lb/f at the wheels, even with a 660cc motor. The question is, can it get that to the ground?

That's dependent on tyres, traction and terrain. Jam a wheel under a ledge and it sure could. I've seen stock CV's snap like twigs with a tyre jammed in a guard.

I've broken 2 rear axles, and it's been on landing after a bounce under power. That's when the car goes heavy and is being compressed into the ground - so traction, for that instant, goes sky high. With the engine spinning hard, sure, instantaneously, there's way more load than the axles (or maybe a weak locker) can handle.

Generating a peak torque figure is simple - it's peak torque times crawl ratio. for a stock sierra, that's about 2900Nm or 2200lb/f The axles will be designed with stock tyres and this figure in mind. Add traction and gearing that figure is easy to exceed.

Steve.

sometimes the allmighty dollar wins, i would love to have had airlockers on my sierra's over the last 8 or so years but sheer price of them being more than the car has prevented me from doing so. I say good on you for trying to keep some costs down and making the rich mans lokker available at a reasonable price. Screw arb they have had it too good for too long and i feel reamed everytime i come out of there store listening to a bunch of large 4x4 owners who have probably never seen the inside of a sierra but still want to tell you whats best for your rig.