Thread: TC V Diff Locks

given that TC functions when wheels are moving at different speeds, and seeing a TC vehicle FIGHT its way up a steep hill, with diff lock, TC would not sense spin of wheels at different speeds etc, so progress should be little less dramatic. Also, consider when TC locks say left wheel, tailshaft is spinning at same speed, so right wheel drives at double the speed to accommodate the stationary left, and is much more likely to spin, TC cuts in, breaks right, releases left, left spins ... and so it goes on.
I'd go for locking diff great for off road and let TC handle tarmac driving.

Originally Posted by rrturboD

given that TC functions when wheels are moving at different speeds, and seeing a TC vehicle FIGHT its way up a steep hill, with diff lock, TC would not sense spin of wheels at different speeds etc, so progress should be little less dramatic. Also, consider when TC locks say left wheel, tailshaft is spinning at same speed, so right wheel drives at double the speed to accommodate the stationary left, and is much more likely to spin, TC cuts in, breaks right, releases left, left spins ... and so it goes on.
I'd go for locking diff great for off road and let TC handle tarmac driving.

I think you've missed the point a wee bit. When TC is activated, it is through the ABS, hence it's not a case of merely locking up the wheel. It's more a case of on/off on/off on/off etc in the blink of an eye.

As for which is better I'd have to say IMO a diff lock would be more definite, but I can't speak from experience, not having experienced one. But I do know for a fact that TC works very well on loose steep ascents and slippery spots.

Cheers

But I do know for a fact that TC works very well on loose steep ascents and slippery spots.

From my limited experience with TC I would have to agree with this. I took a mate out who has a 94 Land Cruiser, we went up a very steep loose track, I got up it quite easily and watched the LC come up, he had a bugger of a job, took the same line up as I did but had to work very hard to make it up, I put it down to the TC.

Depends what you want to do.

To some extent TC is retrospective, whereas a positive locking diff is already operating.

Both have their benefits. If you're into extreme stuff, then the difflock is probably better.

In my car the diff locks are controlled by the management system, so they actually form part of the TC system.

My summary ... they are heaps better than nothing, but not as good as a physical difflock.

The advantages are that they are always on which can be good if you get suprised by a change in conditions. They are quite effective too. They don't interfere with steering the car.

The downsides are they only work for a little while (couple of minutes) and then they overheat and switch off. They are also hard on the braking system if used heavily.

Lockers are slightly more effective (how much depends on the conditions). The only dowsides with them are cost, and if a f&r are fitted steering can be problematic

Originally Posted by Captain_Rightfoot

They are also hard on the braking system if used heavily.

Hang about ... we're talking 'bout a Landie here right?? No reason why they should be needed for more than a few mo's or so.

The new TC systems are very effective - look at a current model Defender or D3. They will however, place a heavier burden on the braking system, and are probably not quite as effective as difflocks. On the other hand, difflocks can easily overload your drive train, especially when one wheel in the air comes down to earth rapidly. And I'd rather change brake pads than half-shafts or CV's. So if you don't need that extra 15% ability, TC is probably far more cost-effective in the long run.

Cheers,

Gordon

Just looking at it from a theoretical point of view - if the need is because a wheel has lifted off the ground, either a locked diff or traction control will be equally effective, at least in theory. However, if the need is because you are operating very close to the limit of adhesion, and one wheel has less grip than the others, the locked diff will have the advantage over traction control that the wheel with less grip will still provide some drive, where the TC will do nothing until that wheel loses grip. Depending on how good the traction control is, the difference may be almost nothing.
It seems to me that in theory at least, if the traction control operates perfectly, the locking diffs will have only the advantage that all the power is used rather than dissipated into the brakes - as almost all vehicles with TC have plenty of power compared to the amount that can usefully be applied to one wheel, this advantage may not be real. It comes down to how good the TC is in doing what it is claimed to do, and annectdotal evidence is that the Landrover system is pretty good.
Two other observations -
If you have all three diffs locked, then traction control will do nothing. (but if your e.g. front diff is not locked, it will help even if the rear diff and centre diffs are locked).
The major drawback of locking diffs is that it enables you to apply 100% of power and torque to one wheel - unless done with care or you have upgraded axles, expect something to break.

John