Adding the Locking Diff to a Syncro ...

[odell]

Hey,

So I know that I'm still learning a lot about the variations in the different Syncros but I wondered if anybody had every but a locking diff in a Syncro that didn't come with one? I can't seem to find the parts on gowesty.com suggestions?

Follow up question would be which of the diffs actually lock up the front or the rear? I have read conflicted articles on both.

Also had anybody ever put a decoupler in? is the install time really around 4 hours?

Thanks!

[RGS Paul]

Ok, to tackle the questions one at a time.

Yes you can put a locking diff. in a non-locker Syncro. You need to have the transmission rebuilt and the parts installed, you also need to install the vacuum system. Don't go to GoWesty for this work whatever you do. Lucas makes you forfeit the entire $2000 core deposit if you send him a non-locker and you received a locker, I believe our quote was over $5500 for a rebuilt gearbox. Darryl at AA Transaxle can set you up for a reasonable amount and a good rebuild. You might need to source some of the vacuum parts yourself, the tank and console are the biggies, but theSamba classifieds are a good source for these. Van-Cafe can also get you all the little fittings and the check valve. Somewhere in theSamba archives there is the '86 service manual that has a good description of the Syncro system.

There are two setups for the diff. locks. In the US VWoNA decided only have the rear locker as an option. That means that on the vans here you can lock the two rear wheels together and push yourself out of the mud. In the rest of the world (except maybe Canada) you could also get a front locker, this is kind of cool since now you basically have to have no traction on all four wheels to get stuck. Front lockers are pretty rare in the US and fairly common in RoW, it is a nice option and you can retrofit it if desired.

We installed a decoupler in our '86 non-locker this spring. It was not a 4 hour job. Running the vacuum system took about 2-3 hours and installing the decoupler took 4-5. Finding the wiring harness to connect to the decoupler took the longest. The seal started to leak as soon as we put fluid in it so Dad had to pull the nose piece again an reseal it. Best modification you can do to a Syncro. It makes it a joy to drive in parking lots and it is killer offroad. We did not put in a solid shaft so we can still leave the front end hooked up on the highway if need be. I lock things up when there is a bad crosswind and I am getting blown around. Now all I need to do is get one of the more aggressive viscous couplings from Europe and we are set.

Calmer more seasoned minds will hopefully weigh in and add their thoughts but this should get you started.

Paul

[Sodo]

I wish there was an option for all 3 conditions

Original (viscous coupling for gravel roads, ice)
Decoupled (city driving, and the freeway slog)
Locked up solid (no delay for driving up onto leveling rocks!)

Does anyone know if this has been done? It seems a bit much to ask.

Tom
_________________


'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb

[Sodo]

Sorry for the hijack (above).

I had a situation with the rear locked, backing down a steep hill I was unable to turn the van (front wheels just slid sideways as all of the weight and traction if this little box was biased on (weighting) the solid rear axle). It made me think that for conditions where you have all 4 tires on the ground, that the Peloquin is a better and easier (perhaps less $ too) option than a solid locker.

Daryl at AA transaxle might be able to guide on this. The Peloquin would be ready at all times like a VC, you wouldn't have to do the little 'locking dance' to get in and out.

Tom
_________________


'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb

[foodeater]

[rfoubi]

so this is a completely uneducated question, but would it be at all possible to put a locker in on a 2wd?

[nohabusguy]

I believe you can put a rear locker on a 2WD. I saw on GoWesty's site that a 2WD vehicle they sold had a rear locker put in. Hold on for sticker shock, though when you look at this.

http://www.gowesty.com/sale_details.php?id=1006
_________________
1967 Double Cab
1967 21 Window Deluxe Bus
1989 Westy Syncro (Subaru 2.5, dreaming of installing a NAHT)
1990 Doka Syncro (WBX 2.1)

[Sodo]

[Sodo]

[Jon_slider]

Here are my thoughts, open to correction, or differences of opinion

1. A solid shaft instead of a Viscous Coupling,

pros
coupled solid shaft transfers equal power to front and rear,
coupled solid is superior in sand, tail does not sink like with VC
decoupled reduces resistance to turning, especially when parking
decoupled allows use of a mismatched spare tire
decoupled saves tire wear
you CAN couple on pavement, and obtain the All Wheel drive traction that a viscous provides
you CAN couple on mountain roads with curves and patchy snow
you do not have to only use the coupler on dirt or deep snow

cons
people think, mistakenly, that coupling is forbidden on pavement
coupling and decoupling is not automatic, the driver has to do it


2. A viscous coupling instead of a solid shaft
pros
my daughter can drive my syncro

cons
front wheel power is always less than rear wheel power, a problem in sand and deep snow
tires wear more than a 2wd setup
steering is stiffer
parking is harder
you cant run a spare unless its been in rotation and is exactly the same size as all the other tires


3. rear locker
pros
can engage to get out of a spot where one rear and one front are spinning, this is strictly for offroad use

cons
expensive add on
driver must engage and disengage, not automatic
will increase sideways slippage on ice or sideslope, but ice is slippery in 2wd too


4. front locker
pros
will give both front wheels ability to turn even if one of them is slipping, offroad use only

cons
expensive add on
driver has to remember to turn it off and on


5. Peloquin or Limited Slip Differential
pros
transfers power to the non slipping wheel,
power transfer is automatic, no driver button pushing required
you CAN buy a LOCKABLE LSD

cons
more expensive than a locker
you cannot turn off the LSD, such as in sand
power transfer happens automatically, and is not truly locked, power pulses back and forth between the slipping wheels, such as on sand, and will dig you down really quickly
There is a concern an LSD would accentuate slipping on ice
if you drop a wheel in a hole the sudden transfer of power to an opposite wheel can push you further towards the hole side


6. using a decoupler with a Viscous Coupling
pros
you get ease of parking,
ability to use a mismatched spare
you can turn all wheel drive on or off whenever you like

cons
power transfer to the front is less than to the rear
in sand the rear of the van rides lower than the front, more likely to get stuck

[Jon_slider]

this is what lockers are for. Im not sure if he has a VC or a solid shaft, try to watch how fast the rear wheels turn relative to the front.

watch his wheels turn even in mid air, thats the lockers

http://youtube.com/watch?v=iGq_6avRbYE

btw, on a 2wd Van, adding rear locker makes the vehicle MUCH more capable on dirt

without lockers, each axle only has to have ONE wheel break into a spin, to totally stop any power going to the other wheel on the same axle

so a 2wd van with locker, can have 2 driving wheels, instead of just one.. this is only on loose surfaces..

NEVER run locked on pavement

so, there is a risk to adding a locker, if anyone else drives your van, they can blow up your drivetrain by pulling a button

[Sodo]

YES! Thanks for pulling that all together. Alll makes sense.

I like the ones that work with no extra input. For example "my daughter can drive it" that's a good thing.

OTOH I currenlty have 5 tires in rotation, consequently am always scared I'll mess up the schedule.

Anyway, just remember that AWD adds complication, and..... you can always buy more stuff to make it more complicated.......
_________________


'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb

[odell]

Ok,

So if I install the decoupler and replace the VC with the solid shaft and I have no front locking diff or front limited slip diff how will the front wheels turn on pavement, snow, ice, etc.? Would I have to install a limited slip diif to use the solid shaft replacement?

Really good info so far, Thanks guys.

[foodeater]

the front wheels can each turn at different rates because you (with no front locker) be running an open differential (where the wheel with no traction spins). with the decoupler engaged and a solid shaft in place of the VC what will always be the same is the torque split between front and rear differentials. Where the VC can allow the front or rear wheels to have more torque the solid shaft always engages both diffs equally.
_________________
89 Bluestar-2.5 Subaru Powered-RIP
'84 Westy Tiico-daily driver-sold
'82 Caddy diesel-sold
'87 Vanagon Syncro-RIP
'81 diesel rabbit-sold
'82 Vanagon auto-RIP

[knucklehead45]

I have not seen any Native US Syncros with stock front lockers. The lockers that I have seen are in England, Sweedan, Finland, Norway and Germany. I am certain they are all over Europe, though those are the only contries I have traveled to. I know a guy in Santa Cruz, CA that brings a couple of the front lockers into the USA a year.

[Jon_slider]

> Would I have to install a limited slip diif to use the solid shaft replacement?

I do not recommend you use a solid shaft, unless you have both front and rear lockers.

I suggest instead, that you keep your VC, and if you want a rear locker, buy a tranny with a locker.

bear in mind that VC's and LSD's are automatic in their engagement and disengagement, although a VC never disengages completely.

so you have 2 different classes of drivetrains, self engaging, or driver engaged.

the self engaging order of preference is
1. VC
2. rear LSD
3. front LSD
4. no decoupler

If you go to a driver engaged system, the order of preference is

1. VC
2. rear locker
3. front locker
4. decoupler
5. only after all the above are already in place, then maybe get solid shaft if you are sure you want to abandon the VC

look again at the Gordon Craig video, as he backs up it seems to me his rear wheels spin more than his front ones, implying he has a VC, even for the extreme terrain he is crawling up, with both front and rear lockers engaged..

Most people who have a VC dont have a decoupler. Rear lockers are much more important than a decoupler. Dont even think about a solid shaft until after you have both front and rear lockers.

Jon O'pinion

[odell]

Jon and everybody else,

So what is the best option (combination of limited slip/locking/de-coupler/etc.) for 90% snow on the way to the ski area and 10% light off-road?

B

[toomanyveedubs]

just bought a syncro today

searched, and found this thread.. good info but i need more.....

like posted before, What is the best option for a mostly road going vehicle that needs to get up the ski hill and do some light duty logging road exploring?

my NEW syncro has NO lockers and wondering if it needs upgrades to do what i want?

From the info given, should i just do the rear LSD???

t

[gears]

All you need is good snow tires, and a parking brake that works (not for parking, but to act as a rarely used diff lock).

[Dogpilot]

There is no best option. I didn't have rear or front locker for a few years. Then I scored a tranny with one, $900 for a rear locking transmission. The front diff are indeed from someplace other than the US. They didn't import them here for liability reasons. The Syncro steers poorly with it engaged, except on soft surfaces. Limited slip is cool, but since your control is lost on when it engages, it can quickly bury both wheels, instead of just one. The lockers allowed you to choose the exact point on the road you want to bury both wheels. There are very strong opinions about LSD's in the snow, so I will not touch the subject.

If your patient, you can find a tranny with a locker. If you have a lot of excess money and it is oozing out onto the floor, or you can not find anything else to light a cigar with, but all those filthy $100 bills, then get a front locker. It is an adventure, mine was a diesel one to begin with, then I found a spare front diff. had both disassembled and the diesel R&P gear removed and replaced with the gas R&P gear. then re-inserted into the locking case, this was real cheap. I have since returned to lighting cigars with all the excess $100 bills.

Your Syncro will work just fine without any lockers. Invest in a shovel and a pull though come along, way cheaper. If the road becomes to crappy, ride your bike. You can buy a Dean Duke Titanium Mountain Bike for the cost of any of the options.

Of all the tranny options I added to my Syncro that makes my daily life better is the un-locker. It is money well spent, unless you like chirping the tires around parking lots when turning tight. It was the first thing I put on my Syncro.
_________________
Geology with a Syncro rocks!
86 Syncro Westy AKA "The Bughunter"
98 Disco I
08 Range Rover SC
08 VW Rabbit S
1951 O-1G