Using Diff-lock on steep descent

[piers]

OK - I give up and my last resort is the wealth of knowledge on 4x4community.

Context
I drive a 2.8i Defender 110 with ARB lockers front and rear.

Question
Do I use the front and/or rear lockers when making a steep descent i.e. Mineshaft at Berakah.

Background
My first (4x4 off-raod) instructor told me never to use these lockers when making a descent, only ever on ascents.
Later I did an "advanced" off-road driving course and the instructor taught that the best method of tricky descents was to use neutral, take foot off the clutch and use the foot brake to descend very very slowly (as in 1 inch at a time).
A few weeks ago, I overheard an "instructor" (no idea if this was a "formal" training session or not) at Hennops advising a group of Newbies to use their rear lockers when making steep descents.

Problem
I have spent HOURS trawling the internet trying to find a CONCLUSIVE answer to this question. There are conflicting answers but very little in the way of decent argument as to which methos would be best/safer.

I have also "experimented" with all three methods down mineshaft at Berakah and found the following: -
Neutral - felt very uncomfortable (personal feeling) knowing there was no drive behind the wheels and also the thought of "what will happen if the brakes fail" didn't sit too well. It also took a lifetime to get down the entire hill.
Centre-lock only - felt fine because I have done most of my off-road like this. Was a bit of slipping, but not enough to make me nervous. I used the air-con to sap a bit of power from the engine and had to feather the brakes slightly to make the speed a bit more confortable for me.
Front and rear lockers engaged - Didn't slip as much as with centre-lock only. Didn't need to use the brakes at all as the descent was slower than with centre-lock only. The vehicle did feel a little less responsive than what I was used to, but this was only the 2nd time that I had done a descent with all the lockers engaged (so maybe feeling isn't a good gauge).

I would like to resolve this issue (for myself) before I need to make a descent in the bush where a mistake could be fatal e.g. Van Zyl's pass.

So what say you all?

[Yimmy]

This is gonna get interesting.

[SimonB]

Later I did an "advanced" off-road driving course and the instructor taught that the best method of tricky descents was to use neutral, take foot off the clutch and use the foot brake to descend very very slowly (as in 1 inch at a time).

In my opinion, and in my experience that is absolute hogwash. All that does is encourage a slide because of the risk of locking the brakes up, and if things go pearshaped, especially on descent with a sideslope, you have no ways of regaining control.

I will NEVER-EVER go downhill in neutral.

With the colt I never felt the need to engage D/L on a descent, but maybe others would feel different. BUT with the lockers on and in neutral the traction advantages of a D/L become redundant as you have no drive to the wheels anyway, so all you are effectively doing is making the vehicle more difficult to steer.

[Naks]

I will NEVER-EVER go downhill in neutral.

I second that.

Depending on how steep the hill is, I engage the lowest possible gear and just steer. If I feel I'm going too fast, I use the brakes very lightly to regain control.

[cmcs]

Neutral in descent.

I can just imagine doing this, and ABS kicks in.....

I often use my difflock going down rocky descends, sure it does kick out the back a bit if I'm going down sideways, but it feels like there is more keeping me back when going downhill. I make a point of using it sometimes and on the same descends not using it to feel the difference.

[Arie]

Neutral - felt very uncomfortable (personal feeling) knowing there was no drive behind the wheels and also the thought of "what will happen if the brakes fail" didn't sit too well. It also took a lifetime to get down the entire hill.

I feel you answered your own question here, when you experimented, and also mentioning the lack of steering control when engaging your lockers.
IMO, Low Range, lowest gear.

[Beans]

Interesting 3 instructors and 3 different versions. Thats why i dont go on a 4x4 course or maybe choose your instructor. T

[Skim]

Neutral - No nO! This means you lose the power of the engin to brake - I normally engage low range with appropriate gear - 1st 2nd and just assist with brake if needed..

M2CW

[Uys]

1st gear, low range, with brakes only if required. Two weekends ago I helped a friend going down steep decents at Serendipity with a 2.5 Mazda. Unfortunatly the vehicle does not have a lot of engine braking, so the brake was required to prevent it running away. At the same spot the Fortuner went down very well without ANY brakes required. My point - first find out how much engine braking you have.

Difflock - I always use it down steep decents unless I expect a really tight corner - in which case I will switch it off just before entering the corner. Why? Two reasons.
1. In axle twisters, if you lift one rear wheel of the ground you lose ALL engine braking if Difflock not engaged. Try the first obsitcle at De wildt without a difflock - you'll see my point.
2. Difflock disables my ABS.

MHO

Uys

[Frans Reichert]

Neutral, Dit is soos om met 'n vragmotor met remme alleenlik teen 'n bergpas af te ry (selfmoord in my oe)

Ek gebruik d/l om gly te beperk as ek teen 'n opdraande opgaan, as ek afgaan haal ek d/l af en skakel in laagste rat, verder beheer ek net die wielglip deurmiddel van my remme. Dit is baie meer beheerd as met die d/l aan.

[Frans Reichert]

H2F as my d/l die ABS onkoppel sal ek ook dit so doen soos jy!

[DouglasN]

When I did my 4WDCSA course a few years back with Geoff, it was a point made deliberately, never do steep descent in neutral and stay away from the brakes.

Steep descent = lowrange 1st, let engine brake, you just steer.

In the years since, some with marshals & rescue unit and some just playing have done many STEEP descents, never an issue. (hilux & ranger)

[bartho van wyk]

Difflock on rear makes sense when traversing through ditches .. Front ? maybe when faced with very steep descents .

Neutral ?? hehehe funny .....

[SimonB]

When I did my 4WDCSA course a few years back with Geoff, it was a point made deliberately, never do steep descent in neutral and stay away from the brakes.

Often it's not possible to stay away from the brakes, especially with a petrol, or if you have bigger than standard tyres. Sometimes I find I am quite hard on the brakes simply because the vehicle is actually going too fast... and then end up stalling

One of the reasons I'd like to eventually change my transfer case ratios (yeah right - I'll never win the lotto)

[bfreesani]

Agree 100% with H2F.... Diff lock on rear to help out through axle twisters on down hills, but then only on the back as locker on the front will limit your steering too much. Neutral = NO NO.... I sometimes go down a hill so slow against the motor assisting with the brakes that I stall the engine. The car should then stop, hanging suspended on the engine compression.

The mine shaft is smooth enough to just go down normal, no axle twister, but has a corner at the bottom, locker could pose a problem here...

M2cW

I don't have lockers, have to improvise and hope that one day my wish list will start coming true...

[Beans]

Simon if you are too hard on the brakes you can cause the same problem as when going down a steep hill as a vehicle in neutral. The problem with newbies is that when in trouble going down a hill is using the brake too much. Same applies on the racing circuit. The other point is that on a very steep decline you can roll your vehicle if you apply the brakes too much Front over backwards.

[camelman]

Allways in gear on a downhill with left foot tucked away under the seat or somewhere it can't reach the clutch. This is why it's important to learn the stall-start method, where you deliberately kill the engine while still in gear and then start it again while still in gear, without using the clutch.

[SimonB]

Simon if you are too hard on the brakes you can cause the same problem as when going down a steep hill as a vehicle in neutral. The problem with newbies is that when in trouble going down a hill is using the brake too much. Same applies on the racing circuit. The other point is that on a very steep decline you can roll your vehicle if you apply the brakes too much Front over backwards.

Agreed Beans... I neglected to mention that this is specifically for rocky terrain where traction is good, but any momentum is bad . But you are absolutely correct regarding loose surfaces, then you might as well be braking on marbles. I've never even attempted descents where your last scenario is a possibility - my life and vehicle are too precious for me...

[roadhawg]

Ok hang on now.

Surely you get to a point where a descent is very steep and very rocky. (One at Bass Dam springs to mind). You need to go really slowly to negotiate the rocks and even 1st low is too fast.

Did it with my buddy in his SWB Rubicon and even with a 4:1 low range it was still too fast. He was STANDING on the brakes and the thing couldnt go any slower (It doesnt let itself stall tho). He came down really fast and hard and if it wasnt for the Rubi's extra bit of suspension he would have broken something for sure on the rocks under the car.

I fully understand engine braking, but surely there comes a point where you need to inch it down on the brakes?

[Beans]

Simon this method does not work on all vehicles but you can pull up your handbrake just until the rear wheels rotate but under load or brake, Put the vehicle 1st low and then decend You can still touch the brake slightly This method acts nealy the same as a rear diff lock when brakes are applied The advantage is that if the brake is applies on a corner and the front wheels lock up we know what is going to happen. Be careful on a vehicle like the Landy that brakes on the prop. Not the best but can work for a novice. Note dont lock up the rear wheels.