Thread: D4 CV Joint Failure ????

Thanks again for everyone's help on this. It would appear that the problem is now fixed, and I may have saved myself quite a few dollars in transporting the vehicle to Perth and having it repaired there.

The Gap IID tool has definitely paid for itself (as has the D4 workshop manual that I bought from Dave quite some time ago). Having a son who is a diesel fitter / mechanic and who is not afraid to pull things apart / play with settings / use diagnostic tools etc is also a big help.

So, today we had the vehicle up in the air. Checked all electrical connections around the transfer case and could see no sign of water ingress / dirty terminals / corrosion anywhere. In fact, for a vehicle with over 120,000km on the clock, the whole transfer case area still looks like brand new. Checked transfer case oil level and condition - level was exactly where it should be and the oil looked very clean and like "new". No sign at all of water in the oil.

Discovered that with the engine off, you could turn the front prop shaft about a quarter of a turn independently of the rear prop shaft, which suggested that the centre diff was not "locked" with the engine turned off. As soon as engine was started, you could hear a distinctive "clunk" from under the vehicle which turned out to be the transfer case clutch solenoid activating / engaging (I could not hear this from inside the vehicle). As soon as this happened, the centre diff was locked, even though not showing this on the main screen display or anywhere else. You could not turn the front prop shaft at all once this clutch had engaged. Shut off the engine, and shortly afterwards, could hear a very distinctive "clunk" from under the vehicle (I had noticed this "new" sound over the past few days). This was the clutch solenoid de-activating / disengaging. As soon as this had happened, you could again turn the front prop shaft about a quarter of a turn independently of the rear shaft.

So - pulled the electrical connection from the clutch solenoid and started the engine - the solenoid did not activate and you could still turn the front prop shaft. Lowered the vehicle down off the axle stands and took it for a test drive. No more shuddering / grabbing / scary noises. Only a "Gearbox Fault" showing on the dash. Worst case scenario - I could drive the vehicle down to Perth like this if necessary, with no centre diff lock available - but this would only be a last resort.

Next, re-connected the electrical connection to the clutch solenoid, plugged in the Gap IID tool, checked all faults and cleared them, then ran both the Transfer Case Clutch Calibration and the Position or Range Sensor Calibration routines as per the instructions in the Gap IID manual. Took vehicle for a test drive and everything working as it should be. Stuck it into low range / rock crawl, observed indication on dash screen that centre diff was "locked", drove vehicle in a tight circle and observed indication of centre diff locking and unlocking as it should do when diff "wind-up" occurred. Then returned all settings to "normal" and observed on screen that centre diff had unlocked. Another test drive to confirm that everything is working as it should be - and I am now sitting down relaxing and enjoying a scotch and dry .................

So it appears that something was sending a signal to the clutch as soon as the engine started, and the centre diff lock was engaging. When the engine was switched off, the diff lock would dis-engage. Exactly what was causing this signal to be sent to the clutch solenoid is a mystery, but I can only assume that the Position or Range Sensor had somehow gone out of calibration and was causing the problem. What caused this to happen is anybody's guess - but at least it's comforting to know that with the Gap IID tool, the workshop manual and the assistance of those with knowledge on here, it's possible to fix these things yourself. especially when the closest dealership or independent workshop I would trust with the vehicle is over 600km away.

Great outcome Brian.... nice to hear it's fixed.

Great to hear and also a good plug for the Gap llD tool as well.


Will put that one in the memory back for future reference just in case.


Cheers Ean

Gap add features such as this when brought to their attention the benefits of people being able to fix simple malfunctions when away from dealers. The TC and e-diff calibrations are great examples of functions added by request.

good stuff and well done
bit partial to scotch n dry myself

Originally Posted by BMKal

So it appears that something was sending a signal to the clutch as soon as the engine started, and the centre diff lock was engaging. When the engine was switched off, the diff lock would dis-engage. Exactly what was causing this signal to be sent to the clutch solenoid is a mystery

We know that e-diffs are pre-armed for take-off even though the diff lock symbol doesn't indicate it and it now seems that the centre diff is too, just that your one had become a little too ambitious.

Originally Posted by Graeme

We know that e-diffs are pre-armed for take-off even though the diff lock symbol doesn't indicate it and it now seems that the centre diff is too, just that your one had become a little too ambitious.

Yes, the centre diff is preloaded just like the e-diff is, I haven't logged it, but it is quite similar in how it works to the e-diff

Well, I'm glad you've managed to work it out, and at (reasonably) low cost!

I would've loved to have this knowledge (and the iidtool) when I was stuck at the tip of Cape York with the same symptoms. I'm almost certain that I had the exact same issue after the water crossing, that could've been fixed without replacing the transfer case!

Thanks for sharing the journey/fix.

Regards

Rob