Club 80-90 Forums

Just returned from a child free night testing out the Syncro camping at Cloud Farm on Exmoor. All was going well till I was trying to navigate a tight bend on grassy slope when my rear wheels stated spinning. Not a problem I thought, pull on the de-coupler and that should engage 4x4 and do the trick. Pull it on - nothing. No little green dot indication light, wheels still spinning. Try the rear diff, nothing. By this point my front is hanging over a small bank with a wall at the bottom, not something I want to fall in to, so I reluctantly ask the site owner for a tow out, while he makes jokes about camper vans and 4x4's It was all good last week and try and make a habit of engaging everything once a month to keep it all moving.

My mechanical knowledge is limited at best so chances of me fixing it are slim. In fact I am not even sure what the de-couper looks like or where it is on the van! I just blew the budget on some new AT tyres for the event so I can't take it in for fixing. So it looks like I wont be able to attend the Devon Syncro event unless it magically fixes itself this week. So cross.

If anyone has a idea of what might have gone on then please feel free to comment. I am going to have a look underneath now the rain has stopped and see if there is anything obvious hanging off. Clutching at straws, yes.

Thanks

If it has been working all this time, and has just now stopped it will most likely be something easy. Maybe a vacuum leak. Pull the knob for the decoupler or diff lock (with engine running) lay under van and listen for a hissing, hopefully you will find a split pipe. Bring the van anyway, you will be unlikey to find another gathering of syncro experts again!
The decoupler is on the end of the gearbox (between gearbox and prop) will have the same blue actuator as the rear diff lock. But seeing as neither are working it will be something common to both of them.

this is the vacuum reserviour for diff lock/decoupler


follow the pipes coming off it, hopefully you will hear hissing somewhere (difflock pulled out)

Thanks Lloydy

Ok, my observations:



This definitely needs a new bolt to hold it over what I am guessing is the decoupler, which I think is this:



which is still in one piece which is good surely!

Looks like a boot has come from somwhere:



Ok so based on what you have said i think i might have found the problem as there seems to be a high groaning sound coming from here which I think leads on to the actuator?



So a leymans guess is pressure is escaping from the above joint causing the fail. Plausible?

The air escaping noise occurs whenever I park up and cut the engine. then it stops....possibly when all the air is out!

first 3 pics are gear linkage, the screw missing is nothing major and nothing to do with your problem.
in your last picture, just below the T joint is a one way valve, is this where you are hearing the groaning? You can pull this valve off and give it a clean with WD40 to free it off

whats this blue bit called please?



Pretty sure its failing as this is where the noise/vibration is coming from, if i squeeze it the noise changes, bit like squeaking a balloon.

ok, Ill give it a clean now....thanks

thats the one way valve, remove and squirt with WD40 then suck/blow through it. then refit

Bugger. Did I mention my wife says I go about things like a bull in a china shop



Oh well, at least I rescued all the bits from the pipes so fitting a new one should be straight forward. The T junction looks to be good and free from cracks.

Do you know where I can get the valve from?

Should I tape up the tubes while the valve is not fitted to keep them clean?

thanks for your help, really appreciate this.

Vw still sell them, I bought one the other day

sound just like me
Aidan should have one https://club8090.co.uk/forum/memberlist. ... file&u=151" onclick="window.open(this.href);return false;
VW still sell them as well

best to cover the open ends, don't want anything getting in there

Brilliant, thanks gents. I'll PM Aiden I think and if not get down my local vw garage.

Cheers for your help. I'll let you know what happens.....

armyphil wrote:Vw still sell them, I bought one the other day

Can you remember what you paid?

thanks

A question. Why did you go off road in 2WD uncoupled mode? I have seen two members here get stuck in a similar manner to you when they couldn't engage the front axle via the de coupler.
The valve you broke is available from VW and the Y pieces etc are a common industrial pneumatics component