So why are they better than a Trutrac or Ashcroft LSD? How much $ ?
Both the Quaife and Ashcroft differentials are better than the Truetrac. They both feature twice the number of helical gears, as well as superior construction.
There would be no defensible reason to purchase a Truetrac given a reasonable exchange rate. Right now, however, the Pound and Dollar aren't playing nice together. That makes the Ashcroft ATB a more expensive option, but not by too much.
Even so, you'll get what you pay for. It's a dramatically improved design. While one could point out the price difference as cause to purchase a Truetrac, it's still not a sensible decision. You need to start with Ashcroft these days. Forget the Truetrac.
None of these are to be considered limited slip differentials. They are torque biasing differentials, and those extra gears and better craftsmanship make a difference. This is not a scenario in which ten more dollars on the price tag gets you one more dollar on the trail.
It's evidenced by the warranty covering the Truetrac. Skip all the nonsense. You have a thirty day warranty, and that's the end of it. Any vehicle on this forum that will require the purchase of any traction aid will void their bullshit one year warranty immediately, and land you right at a month.
Quaife provides a lifetime warranty, and essentially ignores what you do with the vehicle. Even if you fit their product to a racing car, it's covered for life. They just don't give a fuck. If you break it, you get a new one, and you get it fast.
You aren't going to break it, though. I am of the opinion that a Land Rover simply cannot possess any properties required to break a Quaife differential. It's not heavy enough, it's not powerful enough, it can't catch enough air, it won't go fast enough, and you can't fit big enough tires.
Now, Quaife has some funny text in the warranty about the Americas, and I'm not sure why, but I've never heard of anyone here reporting anything less than the same stellar service everyone else receives.
Quaife has a reputation for smooth, predictable performance on the road and track. This is partially because they were always one of only a few manufacturers considered for extreme performance racing vehicles, as well as high performance production vehicles; especially front wheel drive cars that produce too much power for a front wheel drive arrangement.
You'll find them routinely fitted to vehicles exceeding 1,000bhp, as well as rally vehicles that endure abusive scavenger hunt or long-distance stages, and notably in vehicles that do so with larger tires. I've used them in similar conditions, and they are absolutely the cat's ass.
If your vehicle finds itself in a situation requiring higher speeds in abusive conditions, odds are, sooner or later you'll be considering a Quaife differential.
Another facet of their design is the tendency toward slightly lighter bias than other options. This isn't going to help you on technical trails, but it tames a technology that can be a bit twitchy on slippery roads. They don't publish bias figures, because the numbers are quite variable, but you can feel it. It's smoother.
So, you can pretty much ignore the Truetrac. It's irrelevant these days. What you get out of a Quaife is an essentially unbreakable differential that can handle highly abusive runs through variable terrain at speed, while still giving you just enough extra transfer to get you through tougher trails if you know how to use it.
The Quaife, however, comes at a price. You're firmly in air-locker territory, so far as that price is concerned. Shipping and exchange rate play a major part in what you'll end up paying, but by no standard is it a low cost product. These fuckers are expensive.
...Enter the Ashcroft ATB.
I'll tell you right now that I've never used one, but I understand that they are wonderful differentials. I know quite a bit about what's going on inside them, as well as why and how they exist, but I'd rather you ask the man himself about the differences so you can weigh value on your own.
Ashcroft will be more than happy to lay it all out for you, and my personal views are not relevant. They may even be unfair. If what I've heard about the Ashcroft ATB is correct (and it should be, as I've got it on pretty damned good authority) it's a better choice for pretty much everyone else.
In essence, it is a very similar differential. It's almost the same differential. There are reasons I knew I was going with Quaife if I made the move to torque biasing differentials this time around, but those reasons have absolutely nothing to do with the sort of performance in which others are interested.
I ask my Rover to do different things than most. That's why I prefer a limited slip to a locker, and why I'd rather have a torque biasing differential than a limited slip. I briefly considered another option because I'm an idiot, but I changed my mind at the last minute, as a result of some advice and my desire go go torque biasing front, center, and rear.
The center is where things get interesting, actually. If you used torque biasing differentials in vehicles before, you'll note that they can be twitchy when fitted in the front and rear. The car doesn't always know what to do with itself on the road in certain conditions if driven normally.
Once you get the hang of it, though, it's better than open differentials, and very controllable. It's a damned sight better than fully locked, and worlds beyond a Detroit.
Stick one in the center as well, though, and everything changes. The whole vehicle comes together. On wet roads, gravel, snow, and ice, that center transforms the car. You leave behind balancing on the razor edge between dramatic understeer and ass-happy behavior, and gain progressive, controllable four wheel drifts.
PM can explain it with fewer words if I've not done a good job, I'm sure.
I had no idea you could get a center for a Rover until recently, which prompted my immediate interest. You end up with a very capable, very reliable drive-line that can shrug off nearly anything it encounters.
Know, however, that this will
NOT be the case on trails. Lockers are still lockers. Torque biasing differentials are not magic. They give you most of what a locker will, and they give it to you 100% of the time, but that last bit of performance regular rock-hoppers enjoy will
never come out of a torque biasing differential, no matter how many you fit to a vehicle.
Cheers,
Kennith
