Post by: KeithB on December 20, 2016, 10:11:40 PM
Keith
Post by: Watty2975 on December 20, 2016, 10:57:47 PM
It works pretty well. I have tried it a couple of times on some short steep hills. It was nice and controlled. Tried the same hill using just low range and the brakes. Hill decent was better!
Post by: KeithB on December 20, 2016, 11:28:03 PM
Post by: GBC on December 21, 2016, 05:04:11 AM
Post by: cruiser 91 on December 21, 2016, 07:03:30 AM
Engage front and rear lockers when ascending.
Edit: because you have air lockers you can turn off front locker prior to cornering :cup:
Post by: #jonesy on December 21, 2016, 07:03:52 AM
Post by: #jonesy on December 21, 2016, 07:04:49 AM
Post by: scblack on December 21, 2016, 08:13:34 AM
I think the question is if the hill decent works off the ABS and from the few times I've seen it used it alternates the braking around the wheels, applying brakes to only 1 wheel on the same axle, what will happen.The hill descent control will not work as effectively as it could have. It wont break anything - just not work as well as it could. As you say hill descent brakes each wheel independently, or allows power to each wheel. If the axle is locked the process may be compromised, due to drive pushing to a wheel the system is trying to brake.
During descent you would not be using accelerator much I suppose, but the two systems could be somewhat counter-acting each other.
Post by: tombie on December 21, 2016, 08:37:37 AM
Only engage rear lockers when descending.
Engage front and rear lockers when ascending.
Exactly.... front locker will skew the vehicle when descending.
Rear Locker only when descending and HDC will enable control with steering.
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Post by: Hoyks on December 21, 2016, 09:44:18 AM
With a cross axle diff lock engaged there should be no difference in the rotation of the wheels, so the HDC will see it as everything is hunky-dory, and shouldn't engage, on that axle anyway.
The other question is; Are they factory diff locks? I know with the Mazda, using the diff lock causes a few systems like stability and traction control to shut down, so it may be worth reading the owners manual to see if it is likely to make the computers do anything funky.
But, No, I don't think there is any risk of breaking anything by using diff locks and HDC.
Post by: KeithB on December 21, 2016, 04:43:30 PM
It's the same on the LC200. Stability Control goes off when you lock the centre diff. The system doesn't know about the ARB lockers.
I am guessing, having read all of the posts, that if the front, rear and centre diffs are locked the HDC (or the stability control for that matter) won't be able to detect if one wheel is slipping in relation to the others. So how can it do anything?
Post by: tombie on December 21, 2016, 04:49:25 PM
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Post by: Watty2975 on December 21, 2016, 08:13:05 PM
Watty, was that with the diff locks on?
Keith, it was with the centre diff lock on.
Post by: KeithB on December 21, 2016, 09:12:43 PM
I always have the centre diff lock on in rough country. And, contrary to advice in these posts, I will use the front locker (rightly or wrongly) if the the descent is down a dead straight track. Mind you, I am usually towing a camper, which changes the dynamics a bit.
Post by: cruiser 91 on December 21, 2016, 10:08:14 PM
Golden rule when using ARB air lockers front and back with centre diff lock on, high or low range regardless if towing or not.........(I have the centre diff lock mod)
Please see my previous reply post.
I have been taught by a professional and ARB also use this rule, it works...................
There are plenty of Youtube tutorials explaining this rule.
It is hard to go against what feels abnormal until you practice the right way.
Everyone goes through the same..................once you practice the correct way...........it becomes a revelation then a doh! moment, then you feel like a professional 4wder ;D
The only different application with towing is you may have to operate the camper brakes manually instead of using the the vehicle brake.
Having said that, I'm only experienced in a petrol cruiser and I don't use vehicle brakes what so ever in a decent.
:cheers:
Post by: tombie on December 21, 2016, 10:17:40 PM
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Post by: cruiser 91 on December 21, 2016, 10:22:13 PM
If you're not willing to learn why bother asking..Easy there tombie...................its hard to go against what feels right when its not, been there done that ;D
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Its sort of like "when the penny drops" moment 8)
:cheers:
Post by: tombie on December 21, 2016, 10:29:08 PM
Easy there tombie...................its hard to go against what feels right when its not.
:cheers:
My apologies for sounding blunt. But wow!
How can a fully locked up front feel right?
Steering is horrible when locked, if the trailer shoved the vehicle off line it would be nigh on impossible to steer back into position.
Even without a trailer if it starts to turn it will be hard to control.. potentially, dangerously so.
With HDC, rear locked he has the best of all worlds.
Controlled descent speed, vehicle trying to pull straight from its rear diff and steering capability with braking.
Doing otherwise is folly..
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Post by: cruiser 91 on December 21, 2016, 10:32:46 PM
My apologies for sounding blunt. But wow!Absolutely correct!!!!!!!!!!!!!!!!
How can a fully locked up front feel right?
Steering is horrible when locked, if the trailer shoved the vehicle off line it would be nigh on impossible to steer back into position.
Even without a trailer if it starts to turn it will be hard to control.. potentially, dangerously so.
With HDC, rear locked he has the best of all worlds.
Controlled descent speed, vehicle trying to pull straight from its rear diff and steering capability with braking.
Doing otherwise is folly..
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But when the mind of the unconverted says otherwise, its hard to convert to the correct way until the "penny drops" ;D
:cheers:
Post by: achjimmy on December 22, 2016, 05:14:07 AM
....(I have the centre diff lock mod)
Hey cruiser if your talking the ability to lock centre diff in high? The 200s have this standard.
Post by: achjimmy on December 22, 2016, 05:17:26 AM
Post by: cruiser 91 on December 22, 2016, 05:50:50 AM
Hey cruiser if your talking the ability to lock centre diff in high? The 200s have this standard.No I'm not. Not sure why I added that into the mix.
The centre diff lock mod is the ability to turn on and off the centre diff lock manually at will when in low range.
:cheers:
Post by: GBC on December 22, 2016, 07:23:29 AM
Post by: tombie on December 22, 2016, 08:00:18 AM
Brakes And low 1st on a decent rig will more than hold it back.
The front locker engaged will just hinder correct vehicle control...
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Post by: scblack on December 22, 2016, 08:56:21 AM
I just bought an Amarok TDi 420 auto so I'll stick to that. Amarok does have a rear diff lock too.
This is about towing a camper downhill.
Camper has electric brakes of course run by the car - VW dealer supplied electric brakes, 12pin. Amarok does operate anti-sway systems on trailers but my Swan Outback does not have anti-sway fitted.
If I engage the OffRoad mode, which incorporates HDC that obviously operates brakes etc on the Amarok - does that engage the trailer brakes? I assume not, but thought I would put up the question.
If I press the car brakes, that will of course engage the trailer brakes, but will that confuse the HDC systems?
Am I best to manually press the electric brake button to lightly brake the camper? Hopefully this method would be less likely to confuse the HDC system.
I guess I have to get out and test them together, but hopefully I can gather some more info from this topic. My thinking is for driving off-road with camper is the following:
- Engage OffRoad mode (HDC).
- Use tiptronic to hold 1st gear.
- Use electric brake manual button to lightly brake camper.
Depending on steepness - should I engage rear diff lock?
Post by: GBC on December 22, 2016, 09:08:17 AM
Again, with regards the front locker, that is your opinion, mine is different. I've had brake fade from front discs overheating. I'll take traction and engine braking every time thanks.
Post by: KingBilly on December 22, 2016, 09:13:18 AM
Most hdc I've seen will activate a brake light so if your trailer brakes activate off the brake light and not the pedal they will come on anyway.
Again, with regards the front locker, that is your opinion, mine is different. I've had brake fade from front discs overheating. I'll take traction and engine braking every time thanks.
Um, doesn't traction control work by applying the brakes? What am I missing?
KB
Post by: tombie on December 22, 2016, 09:13:25 AM
Regardless - not my rig, not my problem...
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Post by: GBC on December 22, 2016, 09:14:31 AM
Um, doesn't traction control work by applying the brakes? What am I missing?Hdc is just braking.
KB
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Post by: KingBilly on December 22, 2016, 09:15:47 AM
Hdc is just braking.
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Thought it also selected lower gears in the autos and held that gear?
KB
Post by: tombie on December 22, 2016, 09:18:08 AM
Thought it also selected lower gears in the autos and held that gear?
KB
Not in all vehicles...
Better to set yourself up for success..
CDL, Rear Locker, HDC, Low Range, 1st if needed, 2nd if not...
Descending is about smooth and controlled, not slow, you need to keep just enough momentum to maintain control..
Variable speed HDC is brilliant in this regard.
A quick dab of the brakes through HDC can be made as required.
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Post by: GBC on December 22, 2016, 09:36:10 AM
A front Locker does not provide engine braking, nor does it provide traction when descending... what it will do is find the low side of the trail and try to send the vehicle in that direction.
Regardless - not my rig, not my problem...
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I'd recommend re reading what you just wrote.
Post by: Joff on December 22, 2016, 09:54:11 AM
Post by: tombie on December 22, 2016, 09:54:21 AM
I'd recommend re reading what you just wrote.
I'd recommend not. If you can't grasp it that's not my problem... pick rather than learn. Top effort...
Traction in an offroad context is the ability to grip and maintain control.
Being low-sided due to lack of differential action forcing gravity to become an influence is hardly traction as we require it.
Hey, who cares... go do whatever you like.. you'll get away with it most of the time...
I forgot what this forum was like... remember now... full of closed minded, old school, time warped individuals who have no wish to share and debate best practices but rather to just self assert their (often incorrect) methodology upon those who are otherwise willing to listen, learn and expand their understanding.
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Post by: tombie on December 22, 2016, 09:57:36 AM
How bloody fast do you blokes descend really steep stuff to overcook brakes. Sounds like this HDC is more trouble than it's worth.
Spot on Joff
Nothing can replace driving skill..
But HDC is a great tool.. if the vehicle is correctly designed to utilise it.. those with smaller brakes sound like they're fading out easily.
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Post by: Joff on December 22, 2016, 10:26:00 AM
I'd recommend not. If you can't grasp it that's not my problem... pick rather than learn. Top effort...
Traction in an offroad context is the ability to grip and maintain control.
Being low-sided due to lack of differential action forcing gravity to become an influence is hardly traction as we require it.
Hey, who cares... go do whatever you like.. you'll get away with it most of the time...
I forgot what this forum was like... remember now... full of closed minded, old school, time warped individuals who have no wish to share and debate best practices but rather to just self assert their (often incorrect) methodology upon those who are otherwise willing to listen, learn and expand their understanding.
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I think the point being attempted (but I could wrong) was that front diff locks actually do provide traction when descending. In fact they do it far more effectively (given adequate engine retardation) than manual braking. The trouble is ONLY in the steering issue.
The fact is that there is not a 'one size fits all' technique despite what even 'professionals' might assert. If the situation is steep but with little risk of lifting a wheel then engaging a front locker is at best a waste and at worst a danger. But in a situation where the front end is being sprung skyward through cross axle undulations, engaged front lockers are very useful and in vehicles without individually computer controlled brake modulation help enormously. But the steering issue is still there as the tyres transition so caution is needed. (this is why I do not like any form of Auto locker or LSD in off road situations)
The wild card in this is side slip. Open centres deal with side slip better (up or down) because they allow one wheel to spin (or slide) while the other tracks keeping the vehicle (sometimes) from sliding sideways into the ditch. So, going back to the theme that 'there is no one size (or technique) that fits all' it comes down to understanding the way the vehicle behaves, understanding the function of the mechanicals if not the actual mechanicals themselves and applying the most appropriate set of mechanicals and techniques in a given situation.
I will use my front locker down hill if I think it will help me.
Post by: GBC on December 22, 2016, 10:38:47 AM
How bloody fast do you blokes descend really steep stuff to overcook brakes. Sounds like this HDC is more trouble than it's worth.
Its actually the other way around. The cars with HDC will generally go slower than engine braking would allow (otherwise what is the point...) and thus rely way too much on the brakes rather than the whole system and yes it heats up and fast becomes a gimmick when used in anger while towing in Shit country.
We have proven this on the 200 sahara, prado Kakadu and my ranger - all three had oil (melted grease) weeping past the front hubs and smoking off the discs after a particularly long hilly rutted downhill tow on a trip we did into the gold mining area around Newton Boyd. This changed our opinions rather quickly and after that one descent it was 'old school' lockers and low range with pulse braking to save the cars.
Here's someone else who has actually gotten off their arse and done it -
http://www.outbacktravelaustralia.com.au/4wd-mods-traction-aids/harrop-elocker (http://www.outbacktravelaustralia.com.au/4wd-mods-traction-aids/harrop-elocker)
Good reading for anyone who wants to 'learn'.
Post by: tombie on December 22, 2016, 11:10:45 AM
200 brakes are marginal at best without a van on the Arse, Prado marginally better... I concede limited drive time in a Ranger.
HDC should not be solely used to descend a long descent, driving slightly through it uses engine braking and keeps the HDC from rattling away constantly - but leaves it fully functional for those low grip/slip moments.
HDC at its core technology requires exceptional brakes and even if used with lockers will be engaging to slow the vehicles descent - unless gearing / engine braking is greater...
The fact that the Toyota system burns up brakes demonstrates it is inadequate for purpose...
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