Hill descent

I'll have a definite headache as well by now.

If I remember well I would not be able to turn a wheel forward because of the engine compression. It is in gear after all? Out of gear it will act as in your description. I'll probably be wrong here. Maybe a bad memory ????? Kind regards, Erik-Jan.

No it's the extreme case purely for the purpose of illustrating the action of the diff. Engine braking relies on the torque generated on the prop shaft by the rotating rear wheels due to their forward motion being counteracted by the compression of the engine as it is forced to spin faster than it would normally do for the throttle position, which is fully closed.

If one wheel loses grip there is less torque being applied tot he prop shaft as it can be transmitted through the diff to the slipping wheel. Hence no decelerating torque applied to the prop shaft by the engine.

You're not alone.

In message , StaffBull writes

Had them on my ex mil 200 tdi 90. Brilliant in mud, you really can get a lot further in before you get stuck. Front one's not so effective climbing as weight shifts to rear. In fact in some cases it was better to leave the front one out on a steep climb to get better steering control.

In message , Disco Duck writes

Best vehicle I ever drove on snow was a Daf with its rubber belt constantly variable transmissions ratios. The rear wheels could be simultaneously in totally different ratios according to whether they were gripping or not.

Surely that applies to any vehicle, not just a series LR, where the handbrake acts on the prop shaft not the (rear) wheels?

You mean counter rotating wheels on the same axle?

This is a very interesting, complex and dynamic situation. One where your instinctive reaction to the run away, ie brake, is not correct. It requires definate thought and action when gently sliding towards a tree to lift off the brake let alone accelerate...

So the clues to one wheel losing grip, downhill, under engine braking, is simultaneous drop in revs and acceleration. Eeeekkk...

Yes, although I cannot think of others atm. The thing that catches people out with the lr system is when you jack them up, especially with a hilift, on sloping ground..

AJH

Discovery, mine has the characteristic lurch and "settlement" when on a hill. Presumably RRs as well? When people refer to "series Land Rovers" I think of those vehicles that predate the Defender...

The big clue is the large chock supplied with the wheel brace and jack handles... B-)

On or around Thu, 27 Jan 2005 21:20:05 +0000 (GMT), "Dave Liquorice" enlightened us thusly:

yep, if you've free diffs everywhere. If it happens on a series or a locked-centre-diff RR/Disco/90/110 then you've got 2 wheels on the ice. If there's ice on 1 side of the road only, and the other 2 wheels are on dry ground, then at this point you brake, being ready to compensate with the steering wheel for the off-centre braking effect. If there's ice all over the road, you pray that there's a clear patch for it to slow down on again before the next corner...

Disco II, so free diffs everywhere... not (yet) looked underneath to see if the center diff lock spigot is present or not.

OK I have HDC but encountering this single sided ice is just for short sections on public roads that are otherwise treated and clear. So getting into the low box to engage the HDC is not particulary convient. I know where most of these frozen run offs occur but just occasionally there is a new one depending on the recent rain/snow melt levels.

If it's that bad you don't need a corner, it'll be sliding down the chamber, as well as the hill, and into the ditch/hedge/wall/tree (in order of preference)... B-(

Yes the problem will happen with all the landrover products, including the permanent 4wd ones, but maybe less so with viscous centre diff. I meant I couldn't think of another firm that used a prop shaft parking brake.

AJH

Both rear wheels raised!

Once experienced, never forgotten. It's something to practice on play sites. Find a very steep short slope with good run off area. You'll soon get the feel of it.

In message , snipped-for-privacy@despammed.com writes

Perhaps the original idea was to have a brake clear of the mucky wet stuff. Don't forget this was long before the days of disc brakes. Also they were NOT designed to go into DEEP claggy stuff, just normal farm tracks and fields.

I wasn't meaning to particularly criticise the arrangement, in the LR prop shaft brake can have other advantages (useful in the event of brake fade?) and with 50s parking brakes being generally poor the

Once you understand the possibility you can get around it by leaving it in gear, engaging 4wd or locking the diff (mind not so easy with vacuum operated ones)

AJH

Yeah, that was also where I was refering to. Kind regards, Erik-Jan.

And it even has the Hill Descent (snow/ice) button on the dash. Kind regards, Erik-Jan.