Is the electronic diff lock on the 4Motion worth ordering?

[Californication69]

I try to do this at about that frequency, am I correct in only doing so on soft ground (rather than metalled carriageway)?

If I have t used it for 3 months and I’m at home.
I drive into the road, it’s a quiet road, activate it.
Then drive 200 yards up the road.
De-activate it, and drive home.

 

[lohr500]

Our Cali 4M with diff lock option is on order and it will be the 1st VW with a locking diff that I will have owned.

But on all the previous vehicles I have had with diff locks (Jeep Wrangler with front, centre and rear, Land Rover Defenders and Discoveries with centre locks, Haflinger with front, centre and rear, plus various collectable military vehicles fitted with mechanical diff locks) I have always engaged and disengaged the locks at least every other month to stop the mechanisms seizing up from lack of use.
Across the range of vehicles with diff locks, I have had mechanically, electrically and vacuum activated versions.

Never had one fail in over 40 years. For sure I always avoid driving more than a few yards on tarmac with them engaged to prevent putting unnecessary strain on the transmission. And if one doesn't disengage straight away, I stop and reverse on different locks to help take the load off the locked diff.

I am a firm believer that lack of use is the biggest problem with diff locks (and low range transfer boxes come to that), so I will be adopting a policy of gently "exercising" the diff lock on our new Cali on a regular basis.

Having said the above, I'll probably be jinxed now with our Cali's diff lock!!!

 

[AndrewCook680]

I try to do this at about that frequency, am I correct in only doing so on soft ground (rather than metalled carriageway)?

I stand corrected. But in my fomer landcrusier and current Hilux, and now GC680 I have locked diffs and unlocked on metalled roads to “excercise“ them BUT only at low speeds and only driving in a straight line. i believe it’s only when you start turning, going around corners you can cause issues Due to wheels on different sides of vehicle travelling different distances.
in fact when the rear locker on landcruiser once failed to disengage after offroad driving I first noticed issue pulling out at a T-junction when I felt transmission binding.

 

[Viktorgeorge]

Helpful feedback, thanks all.

The conclusion I have come to is: best to regularly (ideally monthly or so) 'exercise' the diff lock. On tarmac slow speed only in a straightline (the handbook actually advises not to 'engage' on a paved/asphalt road surface which I assume means not to use at all). On grass, sand etc. i.e. soft surfaces, straight line not required, but I have noticed that if you do tight turn manouvres on soft ground the diff lock when engaged still causes to rear wheels to seem to challenge each other (manual - says the rer wheels 'rub') so I will still tend toward fairly straight lines and open curves.

I also remember another poster, who had attended a course in Germany on off-road VW 4 motion van driving, suggesting that when in slippery conditions you should first turn off the traction control then keep the diff lock in reserve for when needed. On this basis (perhaps unecessarily) I disconnect traction control when 'exercising' my diff lock.

Interestingly, whilst when I engage the differential lock a red temporary flag confirms this on my digital screen and the relevant push button illuminates yellow - I now cannot see the relevant symbol light up on the instrument cluster but perhaps I have missed that as I try to keep my eyes mainly on the road. Alternatively perhaps turning off traction control affects the symbol display for the differntial lock (as I think I did see it previously), I will continue to investigate.

Any comment appreciated - replacing a seized from lack of use diff locks sounds very expensive.

 

[andyinluton]

On grass, sand etc. i.e. soft surfaces, straight line not required, but I have noticed that if you do tight turn manouvres on soft ground the diff lock when engaged still causes to rear wheels to seem to challenge each other (manual - says the rer wheels 'rub') so I will still tend toward fairly straight lines and open curves.



Any comment appreciated - replacing a seized from lack of use diff locks sounds very expensive.

If rear diff is locked both wheels will travel at the same speed, turn a corner & one wheel needs to turn faster than the other or loose traction & slip. On soft ground one wheel will be able to loose traction & slip, on tarmac with good grip it will either be the diff that gives way first! or despite turning the steering the front tyres will be the ones loosing grip & the van will continue in a straight line.

A diff thats seized due to none use will be stuck in the open position so ok for normal driving. You won't know its stuck until you try & use it.