Descending a steep hill

[caelite]

LandRoverManiac said:

I don't get it either - going down any slope with the clutch down would have got me a good telling off. Anything that entails suddenly loading/unloading the drivetrain such as dipping-in-dipping the clutch would potentially unsettle things.

My instructor always said to use the gears/engine-braking to regulate your speed (selecting the relevant gear beforehand - not changing your mind halfway down), with a foot covering the brakes as backup only if you REALLY, REALLY need them. In most cases it's fighting your natural instincts to dab the brakes - keeping your feet off the pedals and ensuring you go down at a near-as-perfect perpendicular angle.

Just to add - if the hill is *that steep* that you can't tackle it in low-1st in a Defender (which is incredibly low-geared as it is), perhaps don't go down it in the first place if you're worried about damage to the vehicle?

Last point there are 2 issues,
1. It's pretty easy to power up a slope without thinking about it & anticipating the effort needed to get back down.
2. For those of us that do this pish for a living, somethings you just need to wing it, particularly if you have just watched your colleague do it, really pushes you out of your comfort zone, bonus man points when you are in a less capable vehicle with a heavier payload! , normally our Defender 110 TD5 vs Ford Ranger 3.2, Ranger gets lumps beaten out of it following the Defender up a track, objectively speaking its the better motor but aesthetically it is fragile

Although I was taught the same as yourself, don't touch the brakes unless you REALLY have too, ride the engine down in as low a gear as possible, if you have a trailer, lock the wheel brakes and drag it down as a sled, we've had to do this a couple of times, client needed a 4ton generator halfway up a mountain without so much as a logging track on it, got it up with some creative winching, lost 2 tyres on the tri-axle getting it back down.

Personally, don't recommend it unless you are experienced, I find it comfortable to sit a little bit of preload pressure on the brakes, enough to light the brake lights and allow pads to touch discs, not sure what it is but I just feel I get a lot of feedback on my traction through the pedal when I am riding the brake ever so slightly, also has the added bonus of reducing revs on the motor when you are laden.

[LandRoverManiac]

caelite said:

Last point there are 2 issues,
1. It's pretty easy to power up a slope without thinking about it & anticipating the effort needed to get back down.
2. For those of us that do this pish for a living, somethings you just need to wing it, particularly if you have just watched your colleague do it, really pushes you out of your comfort zone, bonus man points when you are in a less capable vehicle with a heavier payload! , normally our Defender 110 TD5 vs Ford Ranger 3.2, Ranger gets lumps beaten out of it following the Defender up a track, objectively speaking its the better motor but aesthetically it is fragile

Although I was taught the same as yourself, don't touch the brakes unless you REALLY have too, ride the engine down in as low a gear as possible, if you have a trailer, lock the wheel brakes and drag it down as a sled, we've had to do this a couple of times, client needed a 4ton generator halfway up a mountain without so much as a logging track on it, got it up with some creative winching, lost 2 tyres on the tri-axle getting it back down.

Personally, don't recommend it unless you are experienced, I find it comfortable to sit a little bit of preload pressure on the brakes, enough to light the brake lights and allow pads to touch discs, not sure what it is but I just feel I get a lot of feedback on my traction through the pedal when I am riding the brake ever so slightly, also has the added bonus of reducing revs on the motor when you are laden.

Well if it comes down to man-points - they should've said that in the video!

I agree pretty much with all of the above - a lot of it for me depends on how much you trust the vehicle you're using/how familiar you are with what feels right/doesn't feel right through the steering/pedals. I always had implicit faith in my old Defender to go wherever I needed it to go - I probably don't have the same supreme confidence in the Disco (it's bigger, heavier and a bit unwieldy across the same terrain - but it's nicer on the road - so I can't have it all).

[InitialDave]

Derek Chevalier said:

If you listen to the bit afterwards he mentions the cross axle. Before going down the hill I believe he had spotted it and therefore concluded that engine braking wouldn't be ideal during this section as it would be inconsistent when wheels lost grip

If you watch at 04:28 here - he blames the anti stall, but watching the vid I'm convinced it's wheels losing traction on the uneven ground

https://www.youtube.com/watch?v=PMhOhT5nwZk

Hmm. Yes. That looks to me like a loose surface shifting out from under the wheels. That close to the bottom, I'd probably try and ride it out, but a light bit of throttle to increase wheel speed up to the point it regains traction could work too. I don't think it's specifically related to the anti-stall. It'll happen any time you have an open diff involved, the wheel with the least traction will spit out the loose stuff and the other wheel will roll more freely, causing you to speed up. Anti-stall or no, if you don't have full lockers, that's always possible there.

If I thought it looked like a risk, I'd go down in one gear higher, with light brake pressure to supplement the reduced engine braking. This would both help balance the traction issue over inconsistent patches, and mean all I need to do to get the compensating increase in speed is come off the brake more.

[caelite]

LandRoverManiac said:

Well if it comes down to man-points - they should've said that in the video!

I agree pretty much with all of the above - a lot of it for me depends on how much you trust the vehicle you're using/how familiar you are with what feels right/doesn't feel right through the steering/pedals. I always had implicit faith in my old Defender to go wherever I needed it to go - I probably don't have the same supreme confidence in the Disco (it's bigger, heavier and a bit unwieldy across the same terrain - but it's nicer on the road - so I can't have it all).

I've always found that with Defender, I've never been a massive Land Rover fan (aye I've noticed your username), always found their higher end offerings far to complicated for actual work, and their lower end offering (Defender) far to expensive compared to competitors. However the Defender, for what it is, is a very easy vehicle to learn offroading in, the seating position is great for visibility as you can easily peak your head out the window to check your wade depth & clearences and it offers, possibly the best feedback of any 4x4 on the market. It is very easy to get behind it on an instinctual level when compared to more insulated modern Japanese crew cabs. However the likes of the L200 & Ranger can be extremely capable once you get used to them, personally I would trust any modern day 'luxury' 4x4 (Disco 3+, RR, Any of the German tat etc etc) about as far as I can punt them, nowadays if you want a tough ladder frame with an uncomplicated, but modern, drivetrain then you are looking at a crew cab pickup or a few niche offerings (Wrangler, G wagon, Jimny... to name pretty much all of them).

Disco of any age is a good tarmac work horse though it must be said, great for towing stuff, the caravanists don't do them justice with there weedy 85% rule vans, based on my experiences in Disco 1s/2s I'd be confident right up to 3.5ton.

[300bhp/ton]

Ayahuasca said:

I was always told to keep feet off everything and descend in 1st low range under engine braking. Defender 110.

However, this instructor (minute 21):

https://m.youtube.com/watch?v=TsY5umMfUxg

States that the hill is too steep for engine braking, so goes down with the clutch pedal depressed and riding the brake!

Any views on whether this is good advice, or insane?

Haven't watched the vid yet. But yes you could use the foot brake to control speed. Although it would be unconventional to use it without any engine braking. That said modern ECU controlled engines and those with anti stall can try to accelerate when revs drop. Which may be undesired if using the brakes and engine braking.

However unless rock crawling or something very technical. Then it is very rare that you'd need or want to travel slower than tickover low 1st. And if a hill is sufficiently steep you may actually want to accelerate down it, to provide stability and prevent the rear of the vehicle either lifting or wanting to overtake the front.

[300bhp/ton]

InitialDave said:

Yes, I know what he said, and the context.

I'm questioning why anti-stall would be a factor provided you did not try and force the rpm below idle speed by braking.

Anti stall is good. As it prevents an engine stalling. Something you could induce by braking at tickover low first without such a system.

However to prevent an engine stalling it will normally try and increase its rpm.

My Jaguar X-Type, while not used off road but does incidentally have a Puma Ford Diesel engine. Does this sort of thing in traffic and it's bloody horrid. Driving it riding the clutch up and down and using the brakes to modulate low speed, walking pace, slightly faster, slightly slower. Sometimes the ECU will on its own suddenly increase the revs. From idle to 1500rpm+ even with your foot off of the throttle pedal and on the brake. It's actually quite disconcerting when it does it. And this is on the level. If a vehicle did it on a steep decent it would be most unpleasant.

[300bhp/ton]

InitialDave said:

Derek Chevalier said:

It wouldn't

So why is he saying to descend on the brakes only, with that as the justification?

That's the bit I don't understand. Brakes in addition to engine braking is perfectly sensible and useful.

For trials use I often have to dip the clutch and slow on the brakes. As low first is just too fast for some situations. This is in my S3 88 with 3.54 diffs. So low first is not as slow as a 6 speed Defender is. But the principle stands.

However you need to read each situation on the terrain type. Amount of grip, hazards and what you are trying to achieve.

[InitialDave]

Yes, I know.

It seems like the entire argument he's putting forward is that anti-stall will not allow the rpm to drop below idle speed, and I don't understand why this somehow creates an issue, because you shouldn't be causing that anyway. I would apply the same techniques to avoid bogging a non-anti-stall engine, and regard that as normal driving practice.

[Hookaduck]

Evening.
So, what does Idle Jack do on the Defender?

[300bhp/ton]

Ayahuasca said:

I was always told to keep feet off everything and descend in 1st low range under engine braking. Defender 110.

However, this instructor (minute 21):

https://m.youtube.com/watch?v=TsY5umMfUxg

States that the hill is too steep for engine braking, so goes down with the clutch pedal depressed and riding the brake!

Any views on whether this is good advice, or insane?

Right, just watched the vid. Although it's actually one I watched ages ago


I agree completely with what they did and what they said in that situation.

I think the video doesn't show the terrain terribly well, they never do. But I suspect in person it was a lot lot steeper and essentially has a ledge that you drop off.

If you went down in just low 1st, well of course you could do this. But the reality is, it'd probably be a very bumpy ride down, and high risk of walloping the underside of the vehicle.


However to go slower than low 1st tickover, you can't really use low 1st. Especially with anti stall, because as you push the brake pedal, it will increase revs to stop them dropping. And as engine rpm will dictate wheel rpm when coupled via the transmission, it will make it much harder to go slower, at best all you'd end up doing is going down at broadly the same speed as just engine braking, but braking force also being applied by the brakes.

But this won't solve the problem if you're trying to go slower than low 1st tickover.


Also remember in this video the 110 is being compared to the Rubicon, the Rubicon as a much lower low range and will go slower in low 1st than the 110 will.


I think the situation was used as more of a demonstration than as an actual need in this video, probably to show how much more capable the JK is in this regard. Low 1st with a little braking would probably have sufficed. But I still agree with the theory and rational.