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1995-2002 Range Rover P38A
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Discussion Starter #1
I have not previously driven an automatic off road so I am having to develop some different techniques. One thing that is a real concern is the poor engine braking. With my old classic, it would idle down the steepest hill but the P38 runs away in low low so its doing 1500 rpm on any sort of a slope and the road speed is way high for anything rough. What is the best down hill technique? Maybe it is ok to use the brakes as the ABS prevents lock up? I am not confident about this as I attacked a greasy down hill slope using light braking and it seemed that I locked up a wheel. It is annoying to me that a range rover would have such poor down hill capability.
 

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Proper off road on steep down hills in a P38 is low range using hill decent. There simply is no real engine braking as you have noticed. Select manual mode, choose first or second gear, DO NOT touch the brakes!! No matter how much you feel the need to wet your pants DO NOT touch the brakes... let the hill decent system do all the work. Once you touch the brakes all bets are off and you are free wheeling down that steep hill hoping your brakes don;t over heat or the ABS doesn;t leave you in the lurch. It has resulted in a few passengers screaming and swearing they will never ride with me again... but it has never failed. Even my sainted 74 year old mother has completed Driving the Naches Pass with only the need for one change of Depends. I am pretty sure that was because the was laughing so hard. :lol:

Of course another options is to pull the ABS fuse for serious off roading because it causes far more issues in wet clay and degrading leaves and pine needles than it is worth.
 

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1995-2002 Range Rover P38A
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Discussion Starter #3
there is no hill descent system on my 1998 model. From my off road experience the other day I reckon, apart from the mental stress, I will break something in the car at the kind of road speeds I am getting on a 30% slope. Arrghhh. I want my manual classic back - throwing a tanty, no one cares, BAU...
 

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LMAO... yea nothing beats an old manual. Odd that your 98 has no hill decent... market difference? My NAS 97 had it even before the Special Vehicles upgrades.
 

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Discussion Starter #5
The really annoying thing is that I finally decided to go the plunge on an auto and decided I was probably being a bit of a girl by being snobby about autos; (also because manual models are impossible to come by)
 

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LMAO... yea nothing beats an old manual. Odd that your 98 has no hill decent... market difference? My NAS 97 had it even before the Special Vehicles upgrades.
That's interesting RRTH. I didn't think Hill Descent as an electronic function came out until the L322. I thought all we got on the P38s was the advice to engage low first gear, select Manual:
DESCENDING STEEP SLOPES
A. Stop the vehicle at least a vehicle length
before the slope, engage LOW range and
then select the lowest gear.
B. Unless it is necessary to stop the vehicle
in order to negotiate obstructions, DO NOT
touch the brake or clutch pedals during
the descent; the engine will limit the
speed, keeping the vehicle under control
provided the front wheels are turning. If
the vehicle begins to slide, accelerate
gently to maintain directional stability. DO
NOT use the brakes or attempt to change
gears.
C. Once level ground is reached, select a
suitable gear for the next stage of the
journey.
WARNING
Failure to follow these instructions may
cause the vehicle to roll over.
 

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Discussion Starter #7
Whoever wrote "the engine will limit the speed" had been smoking something
 

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1995-2002 Range Rover P38A
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Time for a hunt round YouTube. Year or so ago I tripped over a video discussing the difference in techniques off road between manual gearbox and automatic gearbox cars. P38 and something else, maybe manual Disco. Something of zero interest to me (go off road! I'll take a helicopter thanks) but skipping to the conclusions suggested that they found the P38 impressive once you'd figured out the techniques. Presumably there must be a way to safely get down hills. Is there perhaps some sort of link between manual low gear selection and engine management system to hold the revs down when coasting or almost coasting.

Clive
 

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1995-2002 Range Rover P38A
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Hill Descent Control on a P38? What sorcery is this?! HDC was developed for the Freelander when it came out in 1997. The P38 doesn't have it.

What is very important though is that if you descend a steep hill in your thirstymatic P38, you select first gear. There is a little sprag clutch in the gearbox that allows it to freewheel a bit when you lift off the throttle - you've seen it do this. When you select first, a clutch pack locks up this sprag clutch preventing it from being overrun, and transferring torque to the engine via the torque converter.

Unless you're hill-bashing on Venus or grossly overusing them you won't overheat the brakes. Just keep it in first gear and apply the odd little dab of brake if you need to.

I recommend practicing on more gentle slopes first, if you're not used to it.
 

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I've never really worked out what that does. At least on my '98 GEMS it doesn't seem to make a whole lot of difference to the gear selection.
 

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Something comes to mind, correct me when I'm talking nuts. When my 4.6 (Bosch) was adjusted to LPG the guy revved it to 3000+ rpm, when he let go the throttlecable to idle I could see on the screen the injectorpulses were cutted out completely, probably because the amount of vacuum in the throttlebody.
Is it some purgevalve that actuated this? This also works when descending steep hills, for that matter the engine is no more than a big airpump and brakes very well.
If this device fails the injectors keep allowing petrol going in so the brake-effect has gone.
 

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That's kind of a different thing; depending on what type of gas ECU you have it will have a bunch of settings where if it's above a certain engine speed with the throttle shut, it'll cut the fuel off. Petrol ECUs do that too, and indeed my old Volvo had something that cut the idle fuel solenoid off on deceleration. It made about 0.0005MPG of a difference.
 

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Discussion Starter #13
Done all that stuff (select low low, use manual) but the bottom line is that low range or else first gear is not low enough to provide adequate engine braking on anything other than a moderate slope - very annoying especially when talking to Toyota owners (or the response I got last night when moaning to an Isuzu owner re poor engine braking "Mines automatic and I get good engine braking, I guess the pommies don't know much about making 4WDS").
 

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I guess it depends what you're calling a moderate slope. It'll provide more than enough engine braking going down a slope that you'd stand a chance of getting back up.

I've never found Toyotas to be particularly good off-road, for a variety of reasons.
 

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How about the difference in weight of mentioned cars. In my Classic days I had to accept a Lada Niva being superior when in muddy terrain.
 

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That's part of the problem with the Toyotas. There's no weight over the back so on a steep slope they'll just break traction and slither down, desperately trying to swap ends.
 

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Discussion Starter #17
Tried another greasy downhill using the brakes, the ABS was pulsing like crazy so I guess it was on the point of locking up continuously. My concern is you only need to get a little bit sideways on a steep hill say from a skid and you have a rollover. However going too fast down hill is a good way to break something.

however... the P38 is very capable off road, I walked it up a slope a young acquaintance of mine pointed out to me. Quoting him, "I can get my landcruiser (old ute with leaf springs etc) up it if I give it a bit but I'm locked and lifted, lots of guys can't get up it." So one up for the rangy.
 

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Discussion Starter #18
Did some more research on downhill techniques for autos. Main suggestion was left foot braking while giving it a bit of throttle, presumably to get the torque convertor to lock up (but I don't think this is the problem with the rangy, I think first gear is just too high for down hill work). I tried it and got way too much excitement. Other technique was for stall recovery in an auto, leave it in first and back off the throttle so it rolls down against the torque convertor, didn't work either.
So I guess the best approach is to overcome umpteen years of conditioning and use the brakes, all the while trusting the ABS to avoid a lock up.
 

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First in Low range is very, very low indeed. The absolute fastest it'll go down any slope where you're not actually exceeding the grip of the tyres is about 5mph.

You do not need to apply throttle to "lock" the torque converter, it doesn't work that way and you've completely negated any engine braking effect by applying power.

Put it in low range, go down the hill in first. It'll be fine. Most importantly, stop overthinking it.
 

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when you engage MANUAL do you get L M on the dash display, just putting it in low dose not engage manual, you have to push the button.
 
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