Reply With QuoteYou're right mate it can be a pain. I will cut at some point. It's interesting to compare the 3 states of drive but a pain if you stall on a climb and cant unlock cdl before restart...cheers
YarnMaster
Sorry I thought you had. So you are just doing the shuffle, engaging the cdl with the motor running?
My understanding is that the ETC operates with the cdl unlocked parameters if you engage cdl with the motor running, so the end result is the same. The main difference being that the etc is disabled if you start up with the cdl engaged. I did this the first few times I drove the d2 with the cdl installed and found it to be a bit of a pita having remember to disengage before switching off.
I guess it depends what you are doing with the car. I use the d2 for bird watching in areas that require 4wd to access and need to stop and start repeatedly. If you are driving tracks perhaps its not such a hassle.
ForumSage
SubscriberYou're right mate it can be a pain. I will cut at some point. It's interesting to compare the 3 states of drive but a pain if you stall on a climb and cant unlock cdl before restart...cheers
Swaggie
You can interupt with CDL switch wire from the transfer case with a switch and put this on the dash if you dont want to snip any wires.Originally Posted by ozscott
Cheers
Slunnie
~ Discovery II Td5 ~ Discovery 3dr V8 ~ Series IIa 6cyl ute ~ Series II V8 ute ~
Master
Sorry to be so thick but I'm not following something here. Does your above quote only apply to the D2, not the D2a? From reading your previous thread and my recollection of my workshop manual for my D2a, I thought starting the engine with cdl engaged made no difference to etc function. I thought it was the combination of cdl and low range engaged that de-sensitised the etc function. Does anyone know for sure?
YarnMaster
Yes, I'm talking about the behaviour of the SLABS ECU fitted to the pre-facelift D2's from the factory.
And yes the D2a behaves in the way you describe. Fitting the later versions SLABS ECU's to a D2 will make it behave in the same was as a D2a.
I've tried getting an answer out of LR tech support regarding how the SLABS ECU reacts to cdl and range change without success. I guess it is too many years after the work was done. There was apparently training material on the topix/GLR site at one point but LR no longer have this accessible and can't even suggest where this could be found. To compound the problem of finding information, the lead engineer on the ABS /ETC development for the D2 is now a very senior exec in LR so it would be virtually impossible to get an answer out of him.
That said it's fairly safe to assume that the act of locking the CDL will change the behaviour of the ETC regardless of which range is selected. The ETC works to replicate the CDL by balancing torque distribution between front and rear axles. Once the CDL is locked this is no longer required, and the ETC programming is modified to balance torque across each axle only. That isn't influenced by range selection.
ForumSage
SubscriberMy understanding from a knowledgeable dealer at the time was that engaging low range on a D2 had the SLABS ecu behave more aggressively to wheel slip when one wheel was compared to the speed of the other 3 wheels - so traction control still works in high range but not as aggressively. Thats why I put a low range button on the dash (just another HDC from the wreckers) to tell the SLABS ecu that I am in low range and it does make quite a difference if I forget to press it...
The dealer also told me LR were VERY much against people retrofitting CDL to D2's because they said it put too much force through the diffs. I couldnt understand that, but perhaps if they dumbed down the traction control for the Defenders and D2(a) when the CDL was engaged (as the dealer told me they did) they had concerns about the drive train. Personally I cannot see how locking the CDL could cause problems - unless it was possible for both wheels on one axle to be braked at the same time, but my understanding is that this does not happen - ie the system never braked both wheels at the same time (one complete axle) in order to transfer drive through an unlocked centre diff to another axle.
Cheers
Cheers
Master
I'll dig out my manual (or rave cd) and check the operation description again, as my vague recollection is that it does explain some of that, but perhaps not in the detail you want.
I could understand this where silly people used it on hard surfaces but on slippery surfaces it doesn't make sense to me. On the contrary, I was advised that on dirt roads, with corrugations particularly, engaging cdl reduced shock loads on diffs and you should always engage the cdl offroad except on grippy surfaces. The reason is because when the cdl is not engaged, as the wheels on one axle slip and the load on that axle drops, the wheels spin faster and when they re-grip there's a shock load on that axle and diff as the wheel slows down and grips.
Another reason, I was told, for engaging cdl off road on slippery surfaces, is that it reduces the sun gear rotation in the transfer box. These sun gears have a cup shaped copper washer behind them which wear out (crap design if you ask me). I had to change mine over at about 110k km
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