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T3 syncro - adding rear diff lock
skipper - November 11th, 2015 at 04:41 PM

Hi guys. I'm new to this forum.

I'm after a VW syncro. I've sourced a really good one, pop top, EJ22 fitted, air con, ... The problem is, that it is an AWD model without a diff lock. I want a syncro only to add off road capabilities (I've had a hiace 1987 for the last couple of years) - especially beach driving. This one had drive shaft removed (it comes with it though) to save fuel as per seller.

Please, give me some advice, whether rear diff lock can be fitted anywhere in QLD (I'm located in Sunshine Coast).

I'm not a mechanic, but lets say an advanced diy enthusiast (I've done all of my services on my hiace myself). As far as I've searched on the net (samba), I would be capable of fitting a decoupler and front diff lock myself, but not sure about the rear diff lock.

Any advice would be really appreciated
Thanks and best regards

mackaymanx - November 11th, 2015 at 05:00 PM

First off check if your gearbox has the boss for the locker cast on the RH side. From what I have seen the 094 castings have the boss and the 091 castings do not.

Bloke on Bribie Is should be able to do your box for you, can't think of his name at the moment(having a mental blank).

skipper - November 11th, 2015 at 05:05 PM

Thanks mate. I've just texted the guy, who's selling it, to check that. In case, it doesn't have it I suppose, there's no hope? Unless finding another wrecked syncro with it, which I would think is pretty much mission impossible.

skipper - November 11th, 2015 at 06:24 PM

Just received info from seller. No boss on gearbox. Out of luck I guess?

veedubberpaul58 - November 12th, 2015 at 07:28 AM

went down this road a long time ago....we fitted diff locks to 091s 1600 and 1800 kombi boxes as well as the 094 5spd sideshift transporter box.

where theres a will theres a way.....

the trick you have without the cast block is the oring needs to seal on a curved hole in the top corner of the box.

I got a bunch of bosses cnc machined that had an eliptical oring groove which seem to work

the next problem is holding it in there so we made the boss stepped and machined a larger diameter into the cast ribs.....

wow brings back memories of a time where i had spare time haha

skipper - November 12th, 2015 at 07:44 AM

Wow. Some serious mods :) Congrats

To me though it looks it would be even harder to find someone in the area, who has the knowledge, tools and will to do that for me, then finding a proper gearbox :)
Slowly loosing hope to ever find a syncro for my needs in AU :(

skipper - November 12th, 2015 at 08:06 AM

P.S.: do you still have any of those machined bosses? :)

roverv8bay - December 21st, 2015 at 08:24 AM

Gday Skipper I have a mate with a syncro case for sale set up with the right hole. he paid a well know syncro man A $1000.00 deposit to borrow it so he could have his machined then the guy renigged on giving him his deposit back you can call him if your still after 1. His name is Kerry on 0402376367 he may negotiate a price

skipper - December 21st, 2015 at 08:32 AM


Thanks for that. I've missed the van, I was talking about in the original post. I'm still looking though. Not many syncros around or at least not for sale.


roverv8bay - December 28th, 2015 at 07:07 PM

I have this if anyone needs a factory syncro case

skipper - May 6th, 2017 at 09:48 PM

Hey guys. I have a syncro now :)
It's got decoupler, but no rear diff lock, nor the boss.
What's funny though is, that on the list of gearboxes, mine (6P) is classified as diff lock box. ( ) Does that mean, that the guts of it are all there, but it is just in the wrong case?!
Can the guts be transferred into a case with boss, ad actuator and done?


mackaymanx - May 6th, 2017 at 10:45 PM

The 6PA is the box with the diff lock, 6P is with out. See this chart, not all charts online are correct. 

skipper - May 6th, 2017 at 10:54 PM

Aha. Thanks for that. Thought there wasn't something right :)
So back to the start...sourcing 6PA case AND diff :)

skipper - May 8th, 2017 at 03:38 PM

Btw, does anyone know, if the guts of the diff in the P6 gearbox does have diff lock mechanism in? I've found a case with the boss - so am wondering if it is only a quick swap or should I find diff guts with a locker.


mackaymanx - May 8th, 2017 at 03:59 PM

No you will have to find the inner diff parts.


skipper - May 9th, 2017 at 11:04 AM

What about the gearbox internals? All the same between them to cases?


mackaymanx - May 9th, 2017 at 12:54 PM

Apart from the diff the internals are the same.

Scottkombi - May 10th, 2017 at 12:50 PM

AA Transaxle do a LSD selectable rear diff lock for $1400 US plus shipping.

It doesnt say what ratio the diff is but I am sure they would be able to make up what you need to suit your gearbox and vehicle. 

mackaymanx - May 10th, 2017 at 07:49 PM

Just noticed the price of the diff housing has more than doubled since I bought mine from Weddle.

skipper - May 11th, 2017 at 12:19 PM


650USD + who knows how much for shipping to OZ. And that is only the diff lock internals. Then there is the gearbox case + the labour, to swap everything. Oh, and also the vacuum goodies (bracket, actuator, lines, switch, knob etc.). At least I already have a vacuum operated decoupler, so a bit less stuff needed.

Finding a way to justify those expenses to the wife is the biggest problem, I reckon :)

Scottkombi - May 31st, 2017 at 03:50 PM

Try looking up Stuart Stirling from South Africa.

He has loads of syncros that he parts out and lots of gearbox bits - he may be cheaper as the rand is actually lower value than our peso.

skipper - June 1st, 2017 at 09:58 AM

Thanks Scott.

I've just sent him an email. Fingers crossed.

TICK - June 2nd, 2017 at 05:42 AM

How did you go

skipper - June 2nd, 2017 at 06:53 AM

He's got the parts for cca 800$. He'll find out about the freight and get back to me.


skipper - June 18th, 2017 at 07:20 AM

Hey guys.

Stuart sourced all parts for me including the original syncro lock console, brackets, ... etc.
It's already in transit towards Australia :)
Thanks for the advice...will keep you posted.


Scottkombi - June 25th, 2017 at 09:30 PM

Excellent result.

He is a great bloke that Stuart Stirling and a hard core syncro enthusiast.

I am sure he will look after you.

He got me some parts to replace broken bits I needed about 10 years ago - I wasn't sure whether he still had the resources.