Average life expectancy of LSD's in Toyota, Nissan, Mitsubishi 4x4's.

John, I was just using clutches as an example. They don't wear until you use them and the same applies to LSDs. Where and how you drive determines how much use they get.

I have not paid any attention to LSDs for years until I bought this car. From memory the diff is just an open one until one wheel starts to loose traction then the LSD starts applying torque to the other one. This can happen during hard cornering on the blacktop and very easily on loose surfaces in the bush. It is when that torque is being applied that it is slipping and wearing. They don't completely lock the axles which is why they are called "limited".

My Toyota has done about 95% of its 60,000 ks on the blacktop and many people say its LSD should be worn out at 50,000. It is far from it and it will easily spin both rear wheels if I come up against a difficult section of track that I can't get through.

Splits

Don't want to hijack the thread, but I stand by my observation that the LSD - at least the one in my current model Hilux - locks the axles unless forced to do otherwise by a pre set amount of torque difference. You can observe this effect - just do a slow, tight turn in first gear on gravel, the inside wheel will be clawing away at the loose surface. Do the same turn on bitumen and both back wheels grip the surface because the friction between the rubber and road overcomes the built in (ie the limited slip) slip of the diff.
There are, however, many kinds of LSDs. Given the Toyota penchant for simplicity I would guess that mine is at the simple end of the scale. Check out that venerable reference Wikipedia. The current article on LSDs describes many types. One type applies more locking torque as the drive torque increases; another type increases the locking effect as the axles' velocity differences increase.
Back to Bros1's original question - depends. Check out the variety of responses so far - different drivers, different diffs.

Regards, John.

John

I have just been going through a workshop manual and trying to figure out exactly how much torque is being distributed at what time is not easy. The book says, "The partial locking action resulting from the friction plates and discs is automatically increased by the inherent separating forces between the side gears and the pinion gears which progressively increases the resistance as the torque increases".

It says a "partial locking" not a complete one. The link below also says they do not fully lock. This is why car manufacturers fit them instead of auto lockers. If they locked you would have no end of drivers getting themselves into trouble, particularly on wet roads.

The friction plates may partially slip all the time which would cause some wear but I am not sure. The book is non genuine and not that specific and I have not studied them since TAFE in the early 1960s. It has brought back a lot of memories though and they look very easy to overhaul.

I still believe the amount of wear depends on where and how the car is driven. Bros 1 asked how long they should last and I don't believe you can put a positive figure on that. Bush driving should give them plenty of work and wear but they should get a much easier time in cities or on most sealed roads.

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Brian

I have head rounda bouts wear lsds out and tyres.
Cheers Pete