Series II Disco Centre Diff Lock

You need to contact Ashcroft to confirm - as I recall CDL wasn't available but the parts were in there, then they removed the parts totally, and then depending on who you speak to I think CDL might have returned and then gone away again!

Matt

If the spigot is fitted to the TX case, (you can feel from underneath) then Discoparts sell the kit to add it...

Or grovel underneath and see if you have the spigot on the transfer box.= If you have then all you need is the linkage or one of the other cheaper= work arounds that start with a 10mm spanner...

The electronics know when the CDL is engaged and if you switch the engin= e on with it engaged the automatics (HDC and TC for sure and maybe ABS) ar= e disabled... If you engage it with the engine running the automatics stay= enabled but I'm not sure if that is wise as the drive via the locked dif= f and braking from the automatics might "fight".

My DII has a spigot on its transfer box but I'm not paying =A3245 for a =

linkage that may well be identical to that on DI's and available from a =

scrapper...

Yep had a fiddle underneath and it's not there. I've got a disco 1 sitting here all rusted out will the boxes interchange?

Chas

Just out of curiosity (I have a Defender without electronic aids) what's the advantage that people are after when they want to connect up the diff lock when they've got traction control? Does it not do a better job? Does it not make the centre diff lock largely redundant?

I spoke about this to some technicians I met from the Pinzgauer factory recently, traction control via brakes versus diff locks, they reckoned that it was better to have a system that put power through to the wheels rather than reducing the power to given wheels, although they did agree with my observation that diff locks could make you slip sideways on side slopes due to wheels being forced to break traction. This is in the context of cross-axle locks though, not such an issue when talking about centre diff locks.

Well for TC to work you have to be moving ie have all wheels going round and/or give it lots of welly (I believe). Couldn't get my DII on to a back of a low loader a while back due to wheel spin on a rear wheel when stationary. With only about 10' in front of my car to the cab of the low loader and a 6' drop straight of the side inches from the tyres I wasn't going to give it any welly in case it took off or jumped about...

TBH I don't know if the CDL would have made any difference in this case or not but I now carry a 10mm spanner so I can try it...

Oh right, I'd read some time back when TC was being introduced that the TC system worked even when crawling through mud, engine revs quite high but the truck was crawling along keeping all wheels moving and doing better than a few non-TC defenders on mud tyres (the disco was on ATs). I wonder if there's any way to push the computers to work at lower speeds.

Diff locks help to prevent loss of traction. TC kicks in when traction has already been lost.

A lot depends on how you drive it, rather than the speed (I think). My first experience of needing TC was when I was reversing a caravan across a grassy, muddy field, where an inch of standing water had made it so slippery I could hardly stand up. I thought the D2 wouldn't have a hope, in reverse and up a slight slope, but I left it in low box, let the clutch up and let it idle its way through. It shook and grunted and lurched, but it slowly but surely inched the caravan into its barn. I was well impressed. On other occasions, I have brought it to a complete halt by edging one front wheel up a bank and spinning the opposite two until they had dug themselves nice big holes. Speed seemed to make no difference. Under these circumstances, the TC simply didn't work.

So crawling at low engine speed it works well. In traditional cross-axle situations it didn't. I don't understand TC.

Hmm, a tad simplistic ;-) Diff locks also cause traction loss..

On or around Mon, 21 Jan 2008 20:51:10 +0000, Ian Rawlings enlightened us thusly:

true about the TC though - by definition, as with ABS, it's already got one wheel outside speed tolerance for a maximum-lock turn.

Diff locks on corners more or less guarantee traction loss though, as you say, except in pure straight-ahead. The advantage of course comes from driving the slowest wheel. I dare say the ultimate off-roader has both, really. TC won't do much once it's stuck, whereas a difflock might.

Personally, I've got a lot of time for viscous couplings; but they seem to be out of favour and the preference is for a lot of electronics that are, no doubt, more prone to failure. Which is not to say that a VC can't fail, but it's uncommon for it to do so suddenly and without warning.

Physically - yes. Not advisable though, as the D1 has the normal LT230 whereas the D2 has the LT230Q with the "quiet" gearset. (noticed how much quieter the transfer box whine is on a D2? there's your answer). You can remove the front output case from both and swap the CDL parts into your empty case, but pay attention to any possible shimming of bearings that may be required. Badger.

It could use steering inputs to prevent that though, and doesn't need to put the brakes on hard, just increase the resistance to torque on that wheel to put the equivalent amount of torque through to the other side. I suppose that it does however soak up torque on a wheel that isn't turning, whereas a diff lock routes all torque through to the wheel that has grip -- possibly breaking stuff if it's not designed for it!

I'd have thought though that TC has loads of variables that can be tweaked, chances are they're not tweakable by the end user though and are designed in a manner that doesn't really get the best out of it in lots of off-road situations, e.g. only kicking in when wheels are spinning fast. I wonder if the new rangies and discos tune it with their terrain dial thingummy.

Having driving 300tdi with CDL and TD5 with TC, both as autos, I found the TC more useful. TC is a different technique, you need to give it plenty of revs and let the computer decide how much power to take. Plenty being important, if you don't and the computer wants more you are stuffed. Takes getting used to after driving with CDL and the gentle approach. I was also taught by one of the LR Experience guys that if you get totally stuck with TC, you can sometimes in an auto, left foot brake to try and trick the system.

MudMuppet wibbled

That's a standard technique for any off-road driving, in any vehicle, when stuck(ish) in muddy / slippery conditions really. Human controlled TC ... ;)

Works well in DII's without CDL, eh Nige ... ;)

PS, Top-posting marks you out as a bit of a muppet. Continuing to do so invites full muppet status and KF's, just a FYI. ;)

The time I wanted to possibly make use of TC to get onto the low loader I didn't want to give it lots of welly incase it took off and I whacked into the cab of the LL. If I'd remembered my transfer box has the CDL spigot I'd have grovelled about underneath...

Seems that you just give it welly and let it get on with it. I've yet to be on something flatish and slippy enough to warrant trying it. It did just go up a 1:5 to 1:7 hill covered in a few inches of snow over patchy ice the other morning, TC was kicking in but I tend to ease off the go pedal when it does to get all four wheels driving properly again.

Aye, grand it was too.