Syncro - 1 knob, 2 knobs or 3?

[kguarnotta]

Hi guys, I am long time VW owner. Purely air-cooled.

I am contemplating going for a Vanagon Syncro - to have something I can drive year round in the NE - and not worry about getting stuck in the snow or ice.

I am trying to understand the difference between a Syncro with 1 knob, 2 knobs, or 3 knobs - to understand what I really need/want. I don't anticipate doing any hardcore off-road adventures (but that could be fun!).

Can someone give me a simple to understand explanation of the different versions?

Thanks.
_________________
-Kevin
Lincoln, MA

'86 Triple Knob Syncro w/EJ22
'78 Westy
'69 Single Cab
'65 Kombi - EZ-Camper

[nmerrill]

I'll play.
1 Knob = rear differential lock- standard to syncro in US as far as I'm aware.

now there are to options for the other two...
either a front locking diff which was never an option in the US AFAIK.
or
a "center" drive shaft decoupler, often installed with a solid shaft in place of the original Viscous coupling, though not always.

A solid shaft, with the drive shaft coupled is 4x4 - locked, where as the VC renders the vehicle a type of AWD

For snowy roads, et. al. a syncro will get you basically anywhere typically considered driveable, with the right tires. The single knob is icing on the cake.
More knobs need not apply.
Happy hunting!

[ajdenette]

Kevin,

Some US Syncro's came with an optional rear locker and some came with none in other parts of the world the there was also an optional front locker the lockers are operated by vacuum knobs on a panel on the dash. that is what 2 of the knobs are for the third is for what is called a decoupler this is a part added to the transmission output shaft that allows the disconnection to alleviate stress on the drive train as the Syncro does not use a typical center differential rather a fluid coupling called the Viscous coupling. often time when a decoupler is installed the viscous coupling is removed and a solid shaft is installed.

This is the Locker panel found on a Syncro with lockers, the left light is for the front differential lock as there is a switch like the reverse switch to light the light on the panel to indicate that a segment is locked. The middle light would be for a van with a decoupler installed and the light on the right with the straight wheels is the rear locker.
_________________
1985 2wd Westy with 2000 Subaru 2.2 current driver
https://www.thesamba.com/vw/forum/viewtopic.php?t=685635
1986 Syncro Doka Project next in line
https://www.thesamba.com/vw/forum/viewtopic.php?t=732777
1990 Vanagon Syncro Base awaiting body work

[DirtyBlueVan]

[kevinhinny]

Hi Kevin

Single knob - Rear locker
2 Knob - Usually a Decoupler that disengages the drive shaft from the nose cone of the transmission. Some swear that they get better gas mileage with the driveshaft decoupled but I could never measure any significant difference on mine.
3-Knob - Front transaxle locker - Obviously the best off-road or snow capability. I don't think they were offered for sale in the US but can be upgraded to do so.

Call it bling, but I just get a kick out of looking at the three knobs on my dash.
_________________
1984 Wolfsburg Westy
1986 Syncro GL Tintop
1991 Syncro Tintop

[ajdenette]

Now Kevin, I also want to suggest that while I know that Syncro's are great in the snow and have nice heat because of the water cooling I will say that the Salt they put on the roads in Boston will have that van rusting away quickly unless you spend a lot of time and money to wax oil and maintain the body for the winter. I do find that my Subaru's are a great winter driver very similar engines to the air cooled and with the all wheel drive and a good set of snow tires will go just about anywhere in the snow and I don't feel as bad about them rusting away with the salt. but did enjoy driving my Syncro after the salt was clear too many years of winter driving have left a lot of rot I now need to repair.
_________________
1985 2wd Westy with 2000 Subaru 2.2 current driver
https://www.thesamba.com/vw/forum/viewtopic.php?t=685635
1986 Syncro Doka Project next in line
https://www.thesamba.com/vw/forum/viewtopic.php?t=732777
1990 Vanagon Syncro Base awaiting body work

[Steve M.]

https://www.4-wheeling-in-western-australia.com/diff-lockers.html

Good info in the link above

Okay, imo the only real time you are going to use the front locker is when your stuck and you need all four wheels pulling as one at the same time and not letting one spin because it is spinning in sand, mud or snow. The wheels with grip will move you and as soon as the spinning wheel gets traction you're going to move easier.
The problem in my experience with the front locker is that you really cannot steer with it engaged. It will fight you and if you try to force it into a turn your going to break something on the front end from stress.

It's really useful for pulling out in a straight forward direction.
_________________
This free advice is worth exactly what you paid for it.

There are seven days in a week. Someday is not one of them.

[Zeitgeist 13]

Go big or go home.

_________________
Casey--

'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender --> full camper
y u rune klassik?

[danfromsyr]

your $$$ and time/investment will dissolve faster than cotton candy in a rain storm.

buy an AWD astro van, with a limited slip rear diff and snow tires. it will get/go anywhere and you'll end up being several thousand $$ ahead in 5years.


Dan, who has had and has both.
_________________

[vanagonjr]

Damn, I’m in Mass and I wouldn’t dream of driving a Vanagon year round here.
I drive my 1999 Carrera4 911 in the winter....
_________________
John - 86 Wolfsburg Westfalia "Weekender"
Flint reversed 1.8T W/Passat 5-Speed
LiMBO (late model bus club) www.limbobus.org
LiMBO is on Facebook too! https://www.facebook.com/groups/
FAQ thread: http://www.thesamba.com/vw/forum/viewtopic.php?t=525798

[WestyBob]

Ditto about driving in the NE in winter. Salt city. It's a shame because it would be fun in a syncro. But … as they become rarer annually please don't sacrifice one to the rust gods.

[kguarnotta]

Thanks for all the replies - I'll read and re-read them to make sure I get it/understand the different knobs options. I'm also seeing more replies come in as I try to write this.

I get a little lost on the short hand you guys are using and also on the nomenclature as I'm trying understand what it means. Please bear with me as you explain this to an idiot (aka Me.) I'm reading your responses as well as reading the gowesty articles about the transmissions and differentials...and other links you have sent me.

So I'll try to re-read thru the replies- and then come back with a summary - and ask for you guys to let me know if I understood you correctly...

As for money and time/investment...I hear that a lot. "Don't buy them - they are just going to burn a hole in your wallet", "you are just going to spend all your money and time on them".

I get it. At least, I think I do.

At this point I have a 2008 BMW station wagon - great car, amazing to drive, can almost fit my family and stuff in it, but not quite everything I like to haul sometimes. I drive this once the salt starts going down, and if I need to get somewhere quickly.

Once the weather gets nice (ie no salt on roads) I typically drive my '78 Westy although this year I've been driving my '65 EZ-Camper. I really like both of these. My kids like them too. They get pretty mad if I ever talk about selling the Westy.

The thing is the BMW is starting to cost more and more to maintain - and I don't enjoy spending money on it. It's value is going down fast - so I feel like I'm putting good money after bad at this point. It is also a bit too complicated, too many computer parts for me to work on. At least if I'm spending money on an old Syncro - I feel like it isn't lost - as they will hold their value, as long I can keep the rust at bay....

I'd rather sell the Westy and the BMW and get a 1 vehicle I can drive year round. So practically speaking - I need better heat, and a car I can drive in the icy snow conditions I drive in during the winter. We all go skiing together, so a warm car we can all fit in and our skis would be nice. We sleep in the westy a bit too - and I anticipate sleeping in it more, now that my youngest is just about potty trained. The other thing about the Westy - I don't really think I need the cabinets - I think I'd rather have the seats so a weekender interior makes more sense with the way I use my vehicles.

So if I think about what I'm looking for in a vehicle - a pop-top Vanagon seems to fit.
Space for 2 adults & 2 kids to sleep (plus a dog).
Decent Heat
Good to drive year round.
Fun to drive.
4WD

The Vanagon seems to hit what I'm looking for. A syncro seems a step up - and could afford me not having to worry about those times I drive in the icy/snowy conditions.

As for keeping the salt at bay - I've been researching, and think this product called Rust-Veto could be sprayed on the underside each year. It is a waxy sort of stuff, I think it is similar to cosmoline. Helps keep the salt/rust away.

I have not heard or seen of an alternate vehicle that could do what I'm looking for...
_________________
-Kevin
Lincoln, MA

'86 Triple Knob Syncro w/EJ22
'78 Westy
'69 Single Cab
'65 Kombi - EZ-Camper

[danfromsyr]

while I know it's just money and like stated it will diminish as it dissolves.
they only made ~2500 Syncro Campers and ~14000 in the north american market. USA & Canada (yes I know Mexico is NA)


I'll say it again.. AWD ASTRO van
they are still out there in good condition for under $10k and won't sting as bad when the salt & brine takes it's hold.
a 2002-2005 AWD with rear limited slip will go thru any/all new england snow (on snow tires of course)
has front & rear heaters and can still add an Auxillary heater if you want a warm car in the ski parking lot.

sleep in the 78 in the summer..
_________________

[IdahoDoug]

I"m with Dan. Aside from the pop top, an AWD Astro van will fill the bill. I think you should look at a few Syncro Campers and decide if you want to pay $30,000 + for a winter driver. You'll quickly discover selling the BMW will net you a down payment on that amount and you'll also have some serious mechanical bills for the Syncro in the future just like you pay for the BMW now. Minus the airbags, the power, the safety and the comfort of driving the BMW.

I would never try to justify buying a pricey classic for a winter driver in a rust belt state. A few years from now when you've realized you are paying $2000/year in mechanical bills caused by rusted off exhaust, siezed water pump bolts, and leaking brake lines, plus the body seams start oozing red, and your tranny needs an $8000 rebuild, you'll be back on here wishing you'd kept the paid off Bimmer.

If you have to sleep 4, get a long wheel base full size AWD GM or GMC van (larger than the Astro) and you'll have room to sleep 4 in the back, with seats for 5 still up front. Lots of alternatives to what you want to do, actually
_________________
1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[kguarnotta]

Ok - I was afraid this might end up off topic a bit - as there are a lot of questions I have about these syncro vanagons.

Let's put aside whether or not they are appropriate to drive in the NE salty roads - or if they fit what I may or may not need on a daily basis.

I'm just trying to understand the knobs and how they are used, and how they affect the handling, differentials, etc.
_________________
-Kevin
Lincoln, MA

'86 Triple Knob Syncro w/EJ22
'78 Westy
'69 Single Cab
'65 Kombi - EZ-Camper

[doctorsemaphore]

Hey there kguarnotta...try not to get too hung up on this whole "knob" thing. Basically, most north American-market syncros came from the factory with one knob which activates a vacuum diaphragm to lock both rear wheels together to improve traction. Other parts of the world got syncros with a second knob on the dash to activate an identical mechanism in the front differential to lock the front wheels together for even more off road capability. The third knob (middle knob) activated a mechanism that disconnected the front drivetrain so you are not powering the front wheels when on good roads (i.e. a highway). Most factory syncros did not come with this middle knob as the factory didn't implement the driveline disconnect for most production syncros. Now, a few syncros (like my 1986) came from the factory with NO knobs and is really just fulltime all wheel drive, with no ability to lock either differential (I have since added a rear locker and corresponding knob...and thus I now have a one-knobber..yea!). Most people consider the front diff lock for people into more extreme off road conditions, and steering is extremely difficult with the front locked. Hope this helps a bit.

[WestyBob]

[Sodo]

[Kombi///M3]

Some syncros didn’t come with any knobs at all.
My 1985 manufactured date syncro doesn’t have one from
the factory. But I have one now for my decoupler.
Good luck

[kguarnotta]

Wow - Sodo and DrSemaphore, thanks so much.

That is what I was looking for - I'm reminded of Cat's Cradle by Vonnegut (at least I think it was in that book). There is a scientist who is so smart he can even explain nuclear fusion to a child.

Thanks for explaining to me the differences.

I've now got more questions - but my son just broke down in his VW, and my wife called, and I need to rescue them.

Then again - it is just a toy VW bus, and the rechargeable battery ran out of juice.... I think I can handle that.
_________________
-Kevin
Lincoln, MA

'86 Triple Knob Syncro w/EJ22
'78 Westy
'69 Single Cab
'65 Kombi - EZ-Camper