Any S2 Disco drivers out there?

I'd look at the rear trailing arm bushes. If they're cracked, they've gone hard and want replacing. Similarly look at the suspension mounting rubbers. Can't remember if the D2 has a rear A-Frame, but on the D1 this also wears and can give similar effects, though normally it also knocks too ..;)

Ok ta. If they were poorly would that be a good time to fit Polybushes if available or stick with the std fayre?

I'll feed that back to BIL and I believe he is going to speak to the garage on Sunday (they only spoke to my Sis when they dropped the car back) and he can air those points then.

Cheers, T i m

Polybushes are way easier to fit, but I'd replace with standard. Polys wear _much_ more quickly .. just think how long the stock bushes have been on, and figure that if you don't off-road, or even only moderately, you'll likely need to change polybushes every couple of years, if not sooner. If you use it a lot off-road maybe once or twice a year.

Oh, didn't know that. Thanks.

FWIW he had his first disco more than 10 years before he (we) took it off-road at a 4x4 thing at Abbingdon. I must say I was very impressed with it's performance (well, more 'surprised' actually as I didn't really have much to compare it with), taking some very steep / awkward mud covered slopes with relative ease. And this was with the 'restriction' of a std caravan height tow hitch digging in whenever you tried to use a bit of momentum. Much to our surprise he even took on the small river that was the exit and got mud up and over the bonnet and up to the windscreen. [1]

Good fun was had by all. ;-)

Cheers, T i m

[1] It did cost him an alternator shortly after that?

Nice one ...;)

Yeah, we always hose the alternator down after off-roading .. ;)

Though sometimes the wading we do gets a little deep ...

;-)

He drove a couple of rounds of the course. The first with us all in and the second with me diving about round the track with the camcorder getting nice axle articulation and ramp climbing footage. ;-)

Ah. Well, the Fire Brigade were on hand to do that (for charity) but nephew wanted it left 'dirty' to show off to his mates when they got home. ;-)

Nice.

Feck, I didn't know LR did boats!

Q on permanent 4WD if I may. I thought I understood that driving summat like an old Landy on the hardtop in 4WD was a big no no (assuming no freewheeling hubs / whatever and everything locked up etc). The issue being with everything being driven at the same speed (no side to side or front to back diff's) if stuff couldn't slip (like when off road) either summat would break or it would shred the tyres (unless all the tyres were the same circumference and you were driving in a straight line etc). ;-)

So, for permanent 4WD to not do that is there some automatic (electro / mechanical?) trickery that prevents this from being a problem?

I think I understood some 'traction control' worked simply by braking a 'loose' wheel, allowing power to be delivered to the wheel that still had traction but I can't image 4WD doing that or in theory you could often only have 2WD (one driven wheel on each axle)?

Cheers, T i m

Not quite so exciting but this is an example of we have (we built 20+ years ago) having an go. ;-)

Given that it's only a MK11 Escort 1300 under the (heavy) skin, with it's full profile 14" M&S tyres (and diff changed from 3.17 to 4.44:1) it seems to do pretty well when the going gets a /bit/ slippery.

Well, for what we can afford / justify anyway. ;-)

Cheers, T i m

On a Disco there's a centre differential, so altogether it has three diffs. Two in each axle driving the front or rear wheels, and the centre diff driving the front and rear props all the time. So, when a wheel loses traction, say the front left wheel, that wheel will start to spin 'cos the open diff in the front axle will transmit power to the side of least resistance ... but the centre diff is also an open diff, so this also loses power. Effectively on a very poor surface a Disco can lose all traction when only one wheel loses grip. In reality this is a rare (ish, ymmv) occasion when there is so little traction that some power isn't always passed to all wheels, except when off-road. Ice, deep muddy ruts, wet grass! can bring the condition on easily. However, we also have a centre diff, which when locked continues to send power to the rear axle, whatever the front does, thus keeping traction up. The rear axle can also work like the front and lose traction on a single wheel, so with one wheel on each axle losing traction all power goes to those wheels and they spin, thus losing traction. It's roughly the same for all 4x4's with varying differences in diffs/locking/semi-locking/viscous couplings etc etc.

So basically you're right ... a Disco with centre diff locked can easily get 'wind-up' in the system and break half-shafts/UJs etc when there is lots of available traction. It also feels weird to drive on a road ....

A D2 might not actually have a centre diff, some models only came with Traction control, but that's another story ... ;)

LOL, nothing wrong with that at all. We used to weld rear wheels together, weld diffs up, do all sorts of things to make 'stuff' go up slippery hills!

Mind, I prefer more comfortable off-roading these days .. ;)

OK.

Ok.

If 'locked' it sends the power to both front and back equally doesn't it?

Ah, as I thought (above then, even with the centre diff locked etc).

Ok, but I guess there must be some that can dynamically overcome this by automatically locking diffs etc to effectively lock up the entire system (or not)?

I bet. ;-(

So, if TC simply applies the brakes to the spinning wheel (per axle) to provide drive to the one that isn't then again it's only a 2WD vehicle?

Cheers, T i m

Given the choice I'd equally like to do it on summat with only one wheel at the back (and front, so not even my Messerschmitt). ;-)

When daughter was about 6 she had a little PW50 mini motocrosser and would happily go round and round a local off road cct, be it knee deep in mud or choking with dust.

She's happy as her b/f's just bought an old HiLux and I think is hoping to get the Ranger one day (she has her bike licence for 3 years now).

Luckily she has the use of a Quad where they are in Scotland and a good few acres to play with it on.

Cheers, T i m

Yes. Open also sends power to each equally, but allows each axle to rotate independantly (like any diff), the locking diff locks the speed of front axle to the speed of the rear.

Yes. Merc G-wagons have locking axle diffs too, many other systems have some forms of either locking or viscous coupling. Locking diffs can be retro-fitted to Discos, from about £500 per axle upwards ...

Sort of .. but it doesn't fully apply the brakes, it applies them enough to bring the spinning wheel to the same speed as the wheel with traction, thus (hopefully) gaining traction itself. One technique I use a lot when off-roading, even with a locked centre diff is to left footbrake slightly when it's gloopy, almost dragging the brakes, which stops a wheel spinning up (a spinning wheel multiplies the speed due to getting most power) and keeping some power getting down to the ground.

It's pretty amazing what a standard disco can do as stock, even more so with a locked diff .. and when you have, as some D2's have, centre diff and traction control, they're pretty incredible.

Mind, a lot depends on tyres, driver skill/knowledge and picking a good line too ... ;)

But (just so I get this right) would there be any (much) power going to say the front wheels if both were on ice and the rears were on tarmac (with an open centre diff I mean)? With a locked centre diff the 'power' would go to the front (and not be used) but would also go to the rear (and be used)?

Thanks.

Daughter is in the tree surgery game and the Unimog seems to be a favourite tool of many? Do they work off road as well as they look like they should?

Ah, ok, so more like a reverse ABS function then?

Understood.

I can remember us in the course at Abbingdion. We were sat at the bottom of a gully looking at this expanse of muddy track climbing up like a wall in front of us. BIL called out to a marshal "Any tips for this one?" The marshal asked if he had any diff locks / traction control etc and BIL replied "Nope, just low range and a 2.5 auto diesel'. Marshal said "Stick it in second and keep yer foot in!". It did scrabble about a bit near the top and we were all willing it on and it got there . The top was so short I was sure we'd end up grounded but we didn't.

I bet. Considering this was his first time off-road, with a fully loaded car (that was the family transport and holiday caravan tug) and on std tyres both it and he did very well indeed.

We would all love to do something like that again sometime.

Cheers, T i m

With two wheels on the same axle on ice then it's possible with the open diff that they'd get all the power and just spin and you'd go nowhere, but as you say with the locked diff the power would go to each axle evenly.

Oh yes, very much so. Awesome kit.

Yes.

Heh, it gets you like that .. we go green-laning most weekends, to trials occasionally and to Pay 'n Play sites occasionally. It's only this year that we've got another car good enough for towing so now the Disco is being better set up for off-roading.