[4ePajero]

Where is Gerrit Loubser, our in-house traction specialist?

This relates to the Touareg, but could be of value to other vehicles with electronic Traction Control.

I need to have the centre support bearing on the Touareg's propshaft replaced, but I need the vehicle to drive around with.

I was wondering whether I could remove the propshaft and use the Touareg in Front Wheel Drive mode?

What would happen in

• normal (open centre diff) situation
• CDL on (low range)

(from a Touareg brochure)
EDL

Electronic Differential Lock (EDL)
The Touareg has four-wheel EDL. Using four-wheel EDL, a freespinning
wheel is slowed by brake application, transferring torque to a
wheel with traction.

• will the ECU interpret the situation as both rear wheels lacking traction (both "freespinning") or
• will it not realise this because neither of the rear wheels are in fact "freespinning"?

I suppose the difference lies in where it checks for "freespinning". In the transfer case or at the wheels?
If at the wheels, I suspect that it will try to transfer power to the disconnected propshaft, and I will lose all drive?

[4ePikanini]

How urgent?

I should have the Mazda running by tuesday/wednesday and then my pajero can be used while the treg gets operated. (if the pajero is back from motorbake to have some scratches and a diff leak fixed - going in monday)

[4ePikanini]

With regards to the tregg.

Can you not, as with most other vehicles, just unplug the abs distro module harness, and that will disable all traction aids?

[4ePajero]

Thanks for offer - I'll make contact.

I still need to know (for reference) whether there is a "get-me-home" option available.

[RoelfleRoux]

Gerhard,

In the end you will have to test run to get the real answer.

Instinct suggests that if a sensor reads the prop speed, then you will have to disable the TC - maybe pull the ABS fuse.

If the speed sensor is in the transfer case, then the TC should be happy enough.

That said, these cars are low-bed recovery jobs and I would not experiment if it was mine. Rent a R200 a day AVIS runabout.

Roelf

[SimonB]

We've done that on a Disco2 with TC, which smashed a rear diff in the mountains.
We had to pull the ABS fuse and it worked fine.

[Dutchie In Africa]

This was so much simpler when the rear prop shaft in my '70 series 2a broke. Step 1: Put in diff lock, hi -range. Step 2: drive..

[Gerrit Loubser]

Where is Gerrit Loubser, our in-house traction specialist?

This relates to the Touareg, but could be of value to other vehicles with electronic Traction Control.

I need to have the centre support bearing on the Touareg's propshaft replaced, but I need the vehicle to drive around with.

I was wondering whether I could remove the propshaft and use the Touareg in Front Wheel Drive mode?

What would happen in

• normal (open centre diff) situation
• CDL on (low range)

(from a Touareg brochure)
EDL

Electronic Differential Lock (EDL)
The Touareg has four-wheel EDL. Using four-wheel EDL, a freespinning
wheel is slowed by brake application, transferring torque to a
wheel with traction.

• will the ECU interpret the situation as both rear wheels lacking traction (both "freespinning") or
• will it not realise this because neither of the rear wheels are in fact "freespinning"?

I suppose the difference lies in where it checks for "freespinning". In the transfer case or at the wheels?
If at the wheels, I suspect that it will try to transfer power to the disconnected propshaft, and I will lose all drive?

Hi Gerhard, sorry for the late reply (I was busy with a little fulltime 6x6 project we are messing around with at work ). I suppose you have already solved the problem...

Here is my take on it for what it is worth, bearing in mind that I don't know the Treg that well and it has some intricate driveline systems. Also, I have zero experience with the Treg, having never even had the opportunity to sit in one, let alone play with it in the rough stuff and the answers to things such as what you are asking about can be very specific to a particular vehicle configuration. I have read up on the Treg's driveline, though, so here goes:

• If you remove the rear propshaft and attempt to drive in the normal fulltime 4x4 mode, the vehicle will not move, because the rear output shaft of the transfer case (the one that used to be connected to the rear propshaft) will present almost no resistance to motion and this output shaft will simply spin at high speed. The traction control computer obtains its information from wheel speed sensors and, because all of the wheels remain stationary, the ECU will not see any need to start activating the variable center diff lock. I don't think any damage will occur, but you won't be able to drive the vehicle in this configuration.
• If you now lock the center differential, you will be able to drive, as the front output shaft of the transfer case will be forced to spin at the same speed as the rear one, so the front wheels will propel the vehicle. The issue here is that the Treg only allows manual control over the center diff lock in low range and furthermore electronically limits the vehicle speed to 80 km/h when in low range. I suppose you could use the car like this, but it will be frustrating to crawl along at around 80 km/h with the motor howling at 3500 rpm. You would also have to be very careful not to overload the front axle: you have a lot of torque at your disposal. I don't think that any of the sensors will be alarmed and this might be fine as a limp-out-of-the-bush solution, but not really as a temporary solution for normal use.

[Gerrit Loubser]

Just a few points to make this discussion relevant to Super Select equipped Pajeros:

If you ever want to remove the rear propshaft and drive the vehicle as a limp-home measure, remember the following:

• The transfer case will have a gaping hole where the rear propshaft used to enter it. This will have to be covered to prevent the loss of oil and the ingress of foreign matter.
• Be sure to engage the center diff lock (i.e. select 4HLc or 4LLc). The vehicle could be driven in 4H, because the center diff is equipped with a viscous coupling, but this coupling will soon overheat and seize if relied upon to transmit all drive torque to the front axle. When the center diff is locked, the drive torque is transmitted to the front axle via a mechanical coupling and not via the viscous coupling.

[JohanV]

Just a few points to make this discussion relevant to Super Select equipped Pajeros:

If you ever want to remove the rear propshaft and drive the vehicle as a limp-home measure, remember the following:

• The transfer case will have a gaping hole where the rear propshaft used to enter it. This will have to be covered to prevent the loss of oil and the ingress of foreign matter.
• Be sure to engage the center diff lock (i.e. select 4HLc or 4LLc). The vehicle could be driven in 4H, because the center diff is equipped with a viscous coupling, but this coupling will soon overheat and seize if relied upon to transmit all drive torque to the front axle. When the center diff is locked, the drive torque is transmitted to the front axle via a mechanical coupling and not via the viscous coupling.

thanks for that info