Syncro decoupler

[superbus]

Hi,

The VC on my new Syncro seems to be too tight to me, stalls engine on slow turns... I don't want to break anything expensive so think I should probably invest in the decoupler sooner rather than later.

I hear the Syncro services one is best (and cheapest) any other views on this?
I guess for the price it makes sense to fit the solid shaft at the same time, can't think of any reason not to?
If anyone fitted this themselves, roughly how long did it take? Could I do it in a day?

Any other advice appreciated!

Thanks!

[clift_d]

You should also try speaking to Aidan - he was taking orders for decouplers recently

http://forum.club8090.co.uk/viewtopic.p ... 16&start=0" onclick="window.open(this.href);return false;

[KINGPRAWN]

On hard lock at parking speeds mine felt like I had dabbed the breaks but it never stalled!! ... But would stall when parking which was down to the little box behind the tail light( petrol engine)..???

[lloydy]

Hi, personally (and there will be an amazing amount of opinions on this topic) get a working VC first. It's the same price as a decoupler. I have a working New VC and have never seen the point of a decoupler... Until this weekend when I've had the prop off. I can now see why people want them and I am tempted. I think Aidan runs a service where he will build up the syncro services decoupler kit for you and you exchange it for your nose cone. I think the price comes down a bit if a few people commit to getting one. Aidan would be best placed to comment on that.
I would not fit a solid shaft instead of VC as you will never be able to use the AWD on the road again
The how to's I have read say its around a four hour job with basic tools to complete the job, so probably a day when you take into account testing it.
If the price was good I reckon I would get one

[max and caddy]

I prefer the van with all wheel drive, in the wet the front feels a bit loose with the prop off.

However I would prefer to decouple on the motorway to eliminate any drag and wear resulting from...also no worries over tyre sizes or spare wheels.

[ninja.turtle007]

Lloyd, I can't notice any difference driving with a good prop and no prop. How does it feel different to you?

Fit a recon VC and it'll drive as intended.

[lloydy]

Much lighter on the front, less vibes (that might be fine when new prop comes) feels nicer doing full lock turns.
As I kinda hinted at, I had no issues before I removed prop I was happy with how it drove, just surprised at the difference

[max and caddy]

Try it in winter on roads with a bit of slape applied...I no likey.

[syncropaddy]

Get a reconditioned VC and have a Syncro as VW intended!

PS ..... I have a recon VC for sale!

[max and caddy]

Get a reconditioned VC and have a Syncro as VW intended!

PS ..... I have a recon VC for sale!

Thing is...vw did intend for "selectable 4 wheel drive" ....but then shelved the idea...reasons for the decision is open to speculation but I suspect either cost or lack of of user intervention as main culprits.

[superbus]

All interesting points - My view was that a VC is the perfect 4wd for anything other than extrene off road conditions, but with front & rear lockers, would have to be extraordinary to need anything more. In terms of fuel consumption, while I'm not against any possible saving, I tend to think, it's a heavy van and it's never going to be great, so why not have the advantages of full traction at all times. When Audi was developing the Quattro, in some configurations they found the AWD was more economical than a 2WD as there was less traction loss, therefore wasted energy. Not a direct equivalent for us, but ultimately AWD on road will be a safer vehicle than 2WD.

Am I right in thinking that the ultimate combination would be a decoupler with a good VC? Only decouple when in town, parking or on dry roads? In extreme rock climbing or sand, direct AWD would be better, but for most of us not an issue?

How long does a reconditioned or new VC last? Is it miles or age that wears it out?

Thanks for your thoughts!

[footstuck]

As I understand it, VW designed the de-coupler for syncro's pre-production, that's why you can easy do the mod.
Were these fitted as standard equipment on early vans ? or only as a factory extra?

Installing and using them is simple and backed by an original VW design concept and production variant.

I say keep your tight VC (i think VW called that a Sports VC) and fit a de-coupler.
You will have quick response 4WD at the pull of a button, without the need of very careful 'Tyre wear management' (the main cause of VC's failing in the first place).

Off-road at slow speeds, when its needed and you pull the button, it will perform well.
On road when you need it, torrential rain, snow or when driving super aggressive in the wet, pull the button
and it will perform well.
Factory extras are Improvements. Have one mate

[silverbullet]

As someone who also puts up with a pretty firm VC for all driving surfaces, I am also very tempted to fit a DeCo but if the Mrs is to use the syncro all year round, extra operator training will be required

(easy now)

PS what does a de-propped syncro drive like in comparison to a 2wd bus with "sensible" springs? I've never felt the front try and wash out on the SA but maybe that's different again, had the odd tail-twitchy moment on damp off-camber roundabouts

[jed the spread]

I saved this from a couple of years back when we all spoke about the D word at great length. I dont bother talking about them now as its been done to death and It was all settled and summed up as follows,


A The magic figure has been give, thats 5%. This is how much drive that is said to be given to the front via the VC when a decoupler is not fitted Its not hard to understand that 95% goes to the rear wheels via the gear box.

B When a decoupler is fitted, 100% of the drive is given to the rear wheels through the gear box.

Pro's of fitting a decoupler

1,
Q. "reduce the wear and increace the life span of wearing components simples!"
A. True, by fitting a decoupler you are putting 5% more wear on your gearbox that was designed to work with a VC sending 5% up front (it is not a 2wd gear box), this also means 5% more on your rear CV joints that mysteriously failing and you not understanding why are getting 5% more wear..

2,
Q. Jed wouldnt have had to remove his prop with a failed UJ if he has a decoupler fitted.
A. When a decoupler is fitted the prop still turns even though the 4wd is disengaged meaning a failed very graunchy UJ is still turning on the prop and the same unbearable vibration would still be going through the prop. 5% of the the drive is going to the front wheels (it will be helped along with the free turning of the drivetrain too so more like 3% in real terms but I am no expert) it isnt enough to wear out the UJ's on a prop, no way. What about front engined cars with rear wheel drive they go for hundreds of thousands of miles with 100% of the power going down a prop..... and when I do get the full whammy through my prop that is when my 4wd is engaged and is needed when the back wheels spin, or when in your case you would be pulling the knob on your decoupler. Jeds van has done 339921KM more than likely and not unreasonably, general wear and tear caused a UJ to go and the prop having to be removed, if a Decoupler was fitted or not.

3,
Q. Can a decoupler fail and leave you stuck in the middle of nowhere without 4wd?
A. Yes it can, if one was fitted and it broke (because it is a mechanical part and aftermarket) and you are alone and remote you would be in trouble. No decoupler = No failure.

4,
Q. If you put a new tyre on your van you will cook the VC without a decoupler.
A. In the unlikely event you get a total blow out twice in one trip and you have to get a garage/tyre shop to fit two new tires you dont need a decoupler. If you dont want to take 10 minutes and take the prop off (remember you will be on a tar road more than likely) put them on opposite corners so the rolling radius would have stay the same. If you have to put only one spare tyre on with a deeper tread than the rest would not the diff on that axle take up any difference in rolling radius so they stay the same between the front and back axle.

5,
Q. Can a decoupler stop wind up on long drives?
A. Yes. You will have a stiff VC and it is not working like it should, I have personally seen a stiff VC fail open (will only work as a 2wd) much quicker than expected this year (infact it was quite early) due to its stiffness, it worked quicker but became hot quicker and failed quicker. I have video to prove this happens and actually the fact is your VC will be failing if your getting wind up and is getting stiff. A VC is an automatic clutch that sends drive to the front wheels when needed on its own, if you fit a decoupler to disengage the 4wd so you dont get wind up you have still got a VC that is failing and you run the risk of it letting you down big time. A Decoupler is about the same price as a reconditioned VC so I would think its better to fit a new VC and have a working van than to use one of my personal favorites, "put lipstick on a pig" or fit a decoupler to protect a broken VC . Think of your normal clutch on your van or car, when you feel it slipping and on its way out you get it changed so your vehicle works properly.

6,
Q. Does fitting a decoupler mean you will have a knob and a green light?
A. Yes, you will..... But like has been said already by defenders of the decoupler if you have a perfect VC their is no need for a decoupler. If its a willy waving compensation for anyone fitting a green light and a knob then you would be best sorting your Shlong out first.

7,
Q. Does fitting a decoupler make your steering lighter?
A, No, I took the prop off my van due to a failing UJ, it is maintained as it should be and the steering is no different. I fitted a spare prop borrowed from my Doka just this minute and the steering is exactly the same.



Hope it helps,

Jed

[max and caddy]

I still think its worth having...the only negative Is the possibility of failure and being left with 2wd only, the wear on the gear box thing in my veiw is irelavant...5% more power going into the box doesn't mean 5% more wear..and 5% less drag on the poor old drive train may even cancel it out long term. The rear diff will be 95% more worn than the front one on a road use only van then?

As willy waving adornments go its pretty low key in my book and possibly even borderline anorak territory!

It does solve spare tyre size issues...and suspended tows are possible as well if needed.

My VC is good..and the van does drive better,(less nimble) but holds the road worse(front washes out on wet bends), with the prop off..that's on the same van with 2 different VCs, one in early stages of stiffness and one perfect.