Is my Traction Control working???

[milney]

I hope I’m not about to part with a heap of money but I’m concerned that my Traction Control isn’t working. I have a 1999 TD5 Disco II, I have the CDL transfer case, but I do not have the CDL actuator. Therefore no CDL activated.

The traction control makes the noise that it’s supposed to; I know this after reading the following thread… http://www.aulro.com/afvb/technical-chatter/47210-traction-control-noise.html

My first question WILL be easy. When I hear the traction control noise I see the “TC” light illuminate in my instrument panel. Is this telling me that it is working, or that it’s broken?

My second question may be more difficult to answer over the net. I have experienced what I think is called “axle twist”, where for example my front left wheel and rear right wheels are in the air, while the front right and rear left wheels are firmly on the ground. Sadly for me the only wheels that were turning were the ones on the air. I was quite stuck when you consider the only recovery gear I had was the standard jack (it’s now very muddy…).

The other incident that raises this concern was when trying to pull another 4WD out of a bog. Only two of my wheels were turning while the other two (on opposite corners) were spinning, slowly digging me in.

Is this a malfunction or am I driving the vehicle incorrectly? Any suggestions would be appreciated.

Regards,

Milney

[Blknight.aus]

TC does have an "I give up point" hard to find with a manual (you'll stall) but if youve got an auto you can find it. it will also shut down from overheating of the pump if you work it stupidly hard for an extended period (its around 10 minutes of constant use)

and yep the TC light comes on when its working and when its got a fault, if its got a fault it stays on permanant and if its working it turns off about 10-15 seconds after TC has stopped working.

[jmkoffice]

I hope I’m not about to part with a heap of money but I’m concerned that my Traction Control isn’t working. I have a 1999 TD5 Disco II, I have the CDL transfer case, but I do not have the CDL actuator. Therefore no CDL activated.

The traction control makes the noise that it’s supposed to; I know this after reading the following thread… http://www.aulro.com/afvb/technical-chatter/47210-traction-control-noise.html

My first question WILL be easy. When I hear the traction control noise I see the “TC” light illuminate in my instrument panel. Is this telling me that it is working, or that it’s broken?

My second question may be more difficult to answer over the net. I have experienced what I think is called “axle twist”, where for example my front left wheel and rear right wheels are in the air, while the front right and rear left wheels are firmly on the ground. Sadly for me the only wheels that were turning were the ones on the air. I was quite stuck when you consider the only recovery gear I had was the standard jack (it’s now very muddy…).

The other incident that raises this concern was when trying to pull another 4WD out of a bog. Only two of my wheels were turning while the other two (on opposite corners) were spinning, slowly digging me in.

Is this a malfunction or am I driving the vehicle incorrectly? Any suggestions would be appreciated.

Regards,

Milney
You found the limitation of TC. With two wheels suspended and no CDL engaged, TC has an issue performing its calulation of average speed. So NO, it's not your driving it's a limitation of the pre CDL DII. This TC stuck scenario also occurs when two wheels on the same axle alernatively slip whilst the other two wheels are securely on the ground such as on a very steep incline. You need to consider fitting a CDL actuator to use CDL, it's a totally different vehicle especially when TC kicks in.

[simonl8353]

When I hear the traction control noise I see the “TC” light illuminate in my instrument panel. Is this telling me that it is working, or that it’s broken?.

The TC light will illuminate when TC is in operation, if the TC is only momentarily engaged the TC light will still glow for 4 seconds.

I do not have the CDL actuator (It can be locked manually on my '99 D2 somehow), but will be getting one installed eventually. This will be an important backup for when the "3 amigos" return (TC, HDC, ABS warning lights all on) as I'm sure they eventually will. :(

[milney]

Thanks for that guys. I was a bit worried, I've only had the vehicle since just before Xmas and just spent $630.00 to replace the Injector wiring loom (that was a saga). I'm most pleased I don't have to spend money on a TC repair. Now to the phone to find someone to supply and fit a CDL actuator...

Much appreciated,

Milney

[simonl8353]

Thanks for that guys. I was a bit worried, I've only had the vehicle since just before Xmas and just spent $630.00 to replace the Injector wiring loom (that was a saga). I'm most pleased I don't have to spend money on a TC repair. Now to the phone to find someone to supply and fit a CDL actuator...

Much appreciated,

Milney
Electronic CDL actuator can be installed where the switch is mounted in place of the coin tray. (Applies to your D2).
The guys at "All Ranges" in Bayswater on 9762 2600 mentioned it to me last week. Talk to Jamie, I'm not sure if they do the work or were reccommending someone. I was too busy looking at my new General Grabbers and forgot to listen.
If you find out who and how much can you PM me the details.

[McDisco]

Milney

If your in that situation again where you are sutck and you dont mind getting dirty you can actually engage the diff lock with a 10mm spanner (i think). The spigot to engage the lock is on top of the transfer case and you just need to get under and reach up and around to get the spanner on it.

Its difficult but it works. Its just a pain in the ass.

Cheers

Angus

[Redback]

Milney

If your in that situation again where you are sutck and you dont mind getting dirty you can actually engage the diff lock with a 10mm spanner (i think). The spigot to engage the lock is on top of the transfer case and you just need to get under and reach up and around to get the spanner on it.

Its difficult but it works. Its just a pain in the ass.

Cheers

Angus

Yes 10mm spanner:)

And yes pain in the arse:( but worth it

Baz.

[WildOne]

And yes, very dirty......:D
Before climbing under the Disco make 110% sure it's safe to do so, make sure there is no chance of the vehicle moving in any direction while you're under there. That would include sinking further if you're bogged in mud:eek:

[jmkoffice]

The safest way would be to engage the CDL on a flat hard surface before you start playing in the bush. It's too risky to engage it when the vehicle is in an awkward position.

[Franz]

I hope I’m not about to part with a heap of money but I’m concerned that my Traction Control isn’t working. I have a 1999 TD5 Disco II, I have the CDL transfer case, but I do not have the CDL actuator. Therefore no CDL activated.

The traction control makes the noise that it’s supposed to; I know this after reading the following thread… http://www.aulro.com/afvb/technical-chatter/47210-traction-control-noise.html

My first question WILL be easy. When I hear the traction control noise I see the “TC” light illuminate in my instrument panel. Is this telling me that it is working, or that it’s broken?

My second question may be more difficult to answer over the net. I have experienced what I think is called “axle twist”, where for example my front left wheel and rear right wheels are in the air, while the front right and rear left wheels are firmly on the ground. Sadly for me the only wheels that were turning were the ones on the air. I was quite stuck when you consider the only recovery gear I had was the standard jack (it’s now very muddy…).

The other incident that raises this concern was when trying to pull another 4WD out of a bog. Only two of my wheels were turning while the other two (on opposite corners) were spinning, slowly digging me in.

Is this a malfunction or am I driving the vehicle incorrectly? Any suggestions would be appreciated.

Regards,

Milney
"Axle twist" also known as being "cross axled". You will find that by having your CDL engaged, it will be much less likely to get hung up by cross axeling - CDL makes a major difference to how often the traction control kicks in.

The omission of CDL was major msitake by Land Rover (as evidenced by it's reintroduction in the 03MY) and makes the vehicle downright dangerous if reversing down a steep slope (I have a video of this somewhwere and the results are frightening)

I would not use my Disco in off road situations without the CDL engaged. It makes a huge difference to the off road performance of the vehicle.

[LandyAndy]

If any of you have a CDL equiped D2 with no lever when you go off-road find a bank or similar to drive up (to give yourself room) get underneath and lock that CDL with a 10mm spanner.You will be pleasantly surprised just how much better you go with the CDL locked.Keep the motor running whilst doing it as a full restart disables your TC/ABS,a stall is OK it wont cause the TC/ABS to disable.
Build your own CDL lever or buy a kit,well worth the $$$/time to get a heap more off-road capability.
Andrew

[milney]

Thanks again,

As a result of what you’ve told me I posted another question in this forum http://www.aulro.com/afvb/discovery/51797-can-i-have-manual-cdl-lever-my-1995-td5-discovery-ii.html As a result, I’ve decided a genuine D2a Hi/Lo CDL lever from a D2a is the only way to go. I’ve found a supplier (4x4Discovery.com.au - "think outside ...") who is going to confirm price and availability in due course.

I’ll post a new thread with all the confirmed details when I get them.

Milney

[SmokyBear]

The techniques required to negotiate cross axle type obstacles in a Disco II can seem counter-intuitive to someone that has learned in a normal 4wd. In a regular 4x4, spinning wheels and loss of forward momentum dictate backing off the throttle & trying again, lest you dig yourself a bigger hole with your spinning wheels.

The traction control system of the D2 operates by comparing the rotational speed of each wheel with the average rotational speed of all wheels. If any wheel rotates significantly faster than the average, the system applies the brake to that wheel to transfer torque back to the wheels that need it.

In a cross axled situation, any 4x4 will come to a stop, even the D2. A regular 4x4 would require backing off & trying again, but the D2 can drive through if the right technique is applied.

If you use light throttle, the free spinning wheels will spin slowly and the traction control only activates hard enough to slow the free spinning wheels below the activation threshold.

This is where the counter intuitive part comes in. Feed in more power and the free spinning wheels spin much faster than the average rotational speed of all the wheels. The traction control will activate the brakes much harder on those wheels and hence useful amounts of torque are transferred to the wheels on the ground.

I have easily driven through many a cross axled situation with this technique. Try it & you will see. The trick is to induce enough difference in wheel speed to get a robust application of the traction control. This system of getting traction to the ground is not exactly track friendly though. For this reason alone I have now fitted the CDL linkage to my D2, NOT because it couldn't negotiate a cross axle obstacle.

It should be noted that a centre diff lock WILL NOT get you any further in a cross axle situation. Anyone with knowledge of the theory behind diffs & 4x4 systems will understand this. Without the aid of traction aids like traction control or front or rear diff locks, if one front and one rear wheel is in the air, then NO torque will be transferred to ground. All that a centre diff lock means is that two wheels, rather than one, must be free spinning to lose forward drive.

[milney]

Believe it or not, after all this time, just as you SmokyBear have posted your thread, I’ve today received an email from Ashcroft Transmissions in the UK who can supply the CDL lever for a really good price. I’ll also be to 4X4intelligence.com.au for recovery points, a lift and a few other things.

Thanks SmokyBear for the info. On the occasions I’ve been stuck I HAVE reduced revs and tried to reverse out as you have indicated many people do. What you’re saying simply is that next time I should bag ‘em up!?!?!?!?

Cheers,

Milney

[SmokyBear]

Well, don't bag it up, just don't be afraid to gently feed it a little more juice : )
You will feel the traction control grab the brake on the spinning wheels, and the car will almost "walk" forward off the obstacle.

Try feeding different amounts of power, you will soon get a feel for how much is needed to get the traction control to do it's job.

I was lucky enough to secure the cdl linkage from an '04 model for $385 and it's certainly much more track friendly.

[SmokyBear]

The omission of CDL was major msitake by Land Rover (as evidenced by it's reintroduction in the 03MY) and makes the vehicle downright dangerous if reversing down a steep slope (I have a video of this somewhwere and the results are frightening)

This is the very reason that Landrover introduced their Hill Descent system.

In an all wheel drive vehicle with open diffs all round, it only takes ONE slipping wheel to lose all motive power. Likewise, in a hill descent situation, it only takes ONE slipping wheel to lose ALL engine braking effect.

Without a locking centre diff, it is therefore necessary to use traction control to fix the first situation, and hill descent control to remedy the second.

With the centre diff lock engaged the front & rear axles are locked together (just like a normal 4x4) and it takes both one front and one rear wheel slipping to lose either forward motive power or engine braking.

With a CDL engaged it is therefore quite possible to descend a steep hill without HDC, but it is certainly still useful, especially with an auto transmission.

[100I]

I think it was the other way round actually, LR got a bit cocky with their HDC etc and felt a CDL was redundant.


Of course they was wrong...

[porgey]

Hi I just noticed tonight that my CDL light is coming on when I brake.
is there something specific I should look for to rectify this ? I have the model wihout the CDL Linkage fitted

I have a Nanocom but have had problems down loading the ABS and other updates so its back to basics for me .

Thanks in anticipation
George

[midal]

Porgey

There was a thread on this recently.....check to see whether your brake and reversing lights are working....if not, it could be a simple blown fuse which when replaced apparently rectifies the CDL light showing up when braking and of course solves the brake light issue.
Look under Disc 2, strange elec problem.

Cheers
Mick

[porgey]

Thanks . Mick you were spot on .Checked the reversing lights and stop lights both not working.Checked the fuses found a blown 15 amp book states a 25 amp . Anyhow all fixed again . Cheers George

[midal]

Porgey

I'd love to take all the credit but the fact is that another poster came across this problem and put up the solution a little while back.....all I did was direct you to the posts.:p

There is a wealth of info available in this forum and it really is invaluable when you need it. Even if you can't find anything, some of the folks here really go out of their way to investigate and help you out.....can't speak too highly of them, makes the place a goldmine of info.

Anyway, glad you got it all sorted.:D

Cheers
Mick

[porgey]

Mick I didnt find the other posts . But you will still recieve the accolade lol You pointed me in the right direction . I could have spent hours instead of minutes trying to nut it out . Yes I agree there are people on Aulro dedicated to help others . Thanks again George

[DiscoJon]

Great info, explains the noise when things get bumpy too!

[gofish]

Anyone got ideas for an easy at home mod to engage CDL. I would love a propper unit but dont have the cash ATM.

[ozscott]

As said above ETC works best by increasing throttle - as SOON as you back off even slightly the ETC stops actively working. Also having stock or similar pads and good brake fluid makes quite a difference to how effective the ETC is.

Cdl does make quite a difference because when locked there is always a min of one wheel turning at normal speed and by positive mechanical means on each axle even before ETC has to work.

I would avoid electrical actuation of the CDL...mechanical is the way to go. Just a simple t handle push pull cable on the transmission tunnel is as simple and effective and reliable as you can get.

Cheers

[alien]

Anyone got ideas for an easy at home mod to engage CDL. I would love a propper unit but dont have the cash ATM.
I know of a member who made a bracket to fit onto the spigot.
From this he runs a piece of coat hanger wire inside a piece of electrical conduit.
It sits over the chassis and is activated by reaching under the sill as required.
You have to think early in mud or river crossing though;)

[acg]

This is also a pretty good option:


CDL Land Rover Discovery 2 D2 Central Difflock Diff Lock Shifter Set | eBay (http://www.ebay.com/itm/CDL-LAND-ROVER-DISCOVERY-2-D2-central-difflock-diff-lock-SHIFTER-set-/261346479313?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3ALand+Rover%7CModel%3ADiscovery&hash=item3cd976ccd1&vxp=mtr)