diff-lock stuck -panic over!

[Reco]

Hi all -can anyone advise what to do if diff lock gets stuck on?

It went off eventually but was a very worrying moment esp as was front one and long way from home!
It occured to me that it'd be nice to know how to deal with it if happened again.
I'd been turning wheels while gently moving forward and backwarsd but would not go off for a minute or so. Finally I tapped switch a few times and light went out and lock came off. panic over.
Needs more use I expect but a bit hesitant to put it on now!

Can't be first person this has happened to - any ideas?
Cheers,

[syncropaddy]

Well, you are going to have to get underneath for this .....

Disconnect and unbolt the Actuator and pop out the little roll pin that attaches it to the shaft. Dont loose it ..... then some fine emery and some WD40 and free up the shaft by working it in and out. Should be fine after that!

[Reco]

Thanks for that quick response Syncropaddy!

I'll be underneath tommorrow if not pissistently raining!
Was just reading about roll-pin in 'diff-lock-spring pin' post below -with useful pictue so less mechanically able bod like me can find it
One thing I've learned is thers plenty of room beneath to crawl about which is handy!

Cheers

[syncrosimon]

Try putting nearly full lock on, creep forward in G with the diff lock on, it should come on fairly quick, stop immediately, actuaute the diff lock, and should pop in and out fairly quickly. Mine does this about 6 or 7 times before running out of vacuum. You have to find the sweet spot where all the cogs are aligned.

Trying to get the thing to work in a straight line is really difficult, and might make you think it is broken.

[Syncro G]

Would it be possable if the deactivate line has a leak the diff would lock easy with the good line but struggle to get enough vacuum on the bad line to unlock again? If the non return valve near the vac resovwar is working you should be able to retain a bit of vacuum after the engine (thus loud noises) has been turned off - this should be enough to hear a leak when checking lines - try the switch in both positions, the lines sometimes whine breafly when the switch is actuated, thats normal but a hiss isn't.

I found when the locking hose came off my rear locker switch behind the dash, the perfectly working front locker didn't respond eather when the rear switch was on as it leaked so much vacuum there was none avalable in the system, a split pipe could be more subtle though. Does position of the faulty lockers' switch affect the speed the good one works at? As mine was a disconected pipe behind the dash I could hear it leaking badly when the rear was switched on, it was a pritty extreme case though.

[Reco]

Brilliant, thankyou gents!

Just tested it after reading replys and locks are going on and off and confidence restored.
Rear never a problem - on and off straight awy.
Front as you say goes on quicker when on lock but still takes a moment to go off but am now happy it will as has behaved itself several times on the trot now and don't feel the need to pull actuater apart (phew!)

But difinitely slight hissing at the switch which if you play about with leak will stop in some positions (maybe why lock went off eventually after tapping it ) so may be switch seal(?) rather than pipes.
Will investigate for leaks tomorrow in daylight but now confident that not a major problem and shouldn't ever have to try to get home in a straight line! so thanks again for help!

When you say goes on and off several times with engine off how do you know? sure the light may goe on and off but has it actually engaged/disengaged?

Cheers

[HarryMann]

When you say goes on and off several times with engine off how do you know? sure the light may goe on and off but has it actually engaged/disengaged?

I think (Simon? means if you position the vehicle such that the locks are 'free' to engage/disengage ('just' that position found by creeping along with some steering lock on)

you'll find a 'point' at which while stopped, you can emgage/disengage the locks on the dash switches altenately till the plenum chamber vacuum runs out.

So YES, the light will go on and off, because the tell-tale switch on each diff is a TRUE indication of diff-lock pushrod position

NB. If the hiss is underneath and not in the cab then a few places to look are:

1) The one-way valve (in the line feeeding the vac plenum chambers ), a small circular object;

2) The ends of the pipes that attach to the difflcok actuators (throttle units). These can perish and split longitudinally at the ends, I just cut off a couple of inches and push back over the actuator nipples.

To fix the one-way valve (identified by being the only thing in the lines near the vac plenum globes apart from the Tee union)... remove it and test/clean, blow through etc or replace with new (rarely necessary)

Good to know you're keen to have those locks working reliably - one of the best features of the Syncro.

I fill the shielding hoses over the pushrod with grease, but makes some jobs a hassle, cable-ties are good to secure those small lengths of hose.

I've only been caught without them once, and it was embarrassing... Landie drivers looking on

Operate them at least monthly when puling away on loose ground... retain caution with the front (straight line no obstacles) and 'clock' the signs and sounds of the rear being stuck on when on tarmac (mini-roundabouts, jumping, hopping, squealing tyres)

Its very easy (for me) to end a Green lane and forget to turn the rear off for quite a while

[andysimpson]

mistake

[Reco]

Thanks for all that - nice to have clarification that is deffo engaged when light on and vice versa.
Hissing definately in the cab but will be printing info and tips here for future reference.
-which maybe soon as my camper has had prop removed and not tried front lock for about 2 years. Nothing wrong with it at the time just trying to save fuel and not going off much -was glad of rear lock on several occasions though! Will be putting back on soon so will check over all hoses etc.

What a site -where else could you go to get help on this?!

[HarryMann]

.. I suppose there is a condition where the light can be:

1) Off when diff-lock is on

2) On when diff-lock is off

due to:

1) Bad switch, wiring or difflock panel

2) Switch physically sticking

They seem pretty reliable to me though, but you can find horrific corrosion between the switch, washer and diff housing. The spacer washer is probably important to get a reliable switching action. Aidan could confirm or deny that.

The front locker is the one that can get into worse condition long term, less used, less accessible, and uses a shorter pushrod, that can be notoriously difficult to unseize compared to the rear.

It is of course the one locker you need to go OFF as soon as possible after pushing the knob in, for obvious reasons. Sometimes they don't, poor vacuum strength as much as anything else maybe.

[Reco]

Well yes - no need to add the caveat as always exceptions to the rule. I'm just pleased that I now know how they're supposed to work thanks.

I'll get weak vacuum it sorted and make sure I use locks regulalry; no good only using them when you need them I s'pose....

Then sort the camper before next snow - I'm all enthused again!

By the way -anyone know where I can get 4x4 door sticker? pick up has non original door and looks odd without one.

Cheers

[dave friday]

Door sticker,try" Brickwerks".

[Reco]

WAHOOOOO! Sorted!

Fixed the leak and all working perfectly -even found the 'sweet spot' Simon was on about: it now goes on / off, on/ off, on/off.......as you like!
One short hiss when switch pushed in and lock goes off, but sounds like it s'posed to do that and not the continuous faint puncture-like hissing it was.

All rubber hoses looked good; the fault seemed to be the inner part of the switch was moving about and sliding out of the outer part causing airleak. The rear lock switch had small jubilee clamp holding outer tight to inner part (between first and 2nd hoses). So fitted cable tie in same place on front lock switch and put back together. All good.

{Re 4x4 door sticker - cheers I'll take a look}

[syncrosimon]

Good man

[Syncro G]

The rear lock switch had small jubilee clamp holding outer tight to inner part (between first and 2nd hoses). So fitted cable tie in same place on front lock switch and put back together. All good.

Interesting, are they ment to be like that? Mines got exactly the same clip arangement on the rear switch (again not the front), which I asumed ment its been bodge repaired, though it works perfectly so I leave it be. Might worry less about it now.