Shopping for syncro - 3 knob questions

[syncro surf]

[Sodo]

[Bleyseng]

I heard the PO was traveling at 65mph on a hot/warm day on a camping trip loaded when the VC blew up, (locked up). The paperwork (2005) doesn't say what was replaced other than transmission rebuild, new VC and a decoupler installed.

Yes, I have the bars removed so I can service the transmission and front diff right now. Derusting the bars and painting them before reinstalling. Trying to get the rear locker switch and the decoupler switch to work so the lights in the panel go on when engaged,
_________________
70 Ghia Black convert-9/69 build date-stock w/133k 1600 SP-barn find now with a rebuilt tranny and engine
77 Westy 2.0L w/Ljet, Camper Special engine-95hp and with LSD!(sold)
76 Porsche 914 2.1L L20c, 120hp Djet (sold)
87 Syncro Westy Titan Red 2.1L 2 knob 100k miles

[MsTaboo]

[Bleyseng]

Stock tires then but the invoice has a new VC listed as installed along with a decoupler. The PO stated the VC locked up/blew up causing the damage and ruining the trip.
_________________
70 Ghia Black convert-9/69 build date-stock w/133k 1600 SP-barn find now with a rebuilt tranny and engine
77 Westy 2.0L w/Ljet, Camper Special engine-95hp and with LSD!(sold)
76 Porsche 914 2.1L L20c, 120hp Djet (sold)
87 Syncro Westy Titan Red 2.1L 2 knob 100k miles

[Howesight]

I had Darryl Christiansen install a locker in my front diff years ago when he rebuilt it and my transaxle. I also purchased a de-coupler at that time. For a data point, I can comment on my experiences.

With many years behind me now, I think that the front locker was not necessary (knock on wood). It`s nice to have, in case of serious mud or snow, but I have yet to be in a circumstance in which it was absolutely necessary.

The de-coupler, on the other hand, is a great addition. I always imagine the worst case scenario that might occur deep in the boonies and one of those is two flat tires requiring me to use some donor wheel or tire combo that is a different size. The decoupler would let me slowly get out of the woods. Similarly, a front half-shaft or CV failure might benefit from using a decoupler.

My decoupler is set up in an aggressive engagement, so I also leave the decoupler de-coupled unless on a long, straight stretch or on a slippery or gravel or muddy surface. The rear locker is the key to good off-road capability, in my experience. On pavement, when making any tight turns, I need to be de-coupled.

Having said all that, I don`t beat on my rig nor do strenuous off-roading or rock crawling type of manoeuvers, so YMMV.
_________________
'86 Syncro Westy SVX

[pnwkayaker]

This is an anecdote-only, but shows how good is the design of a Syncro is (and a warning of additional parts to carry):

At one NorthWest MogFest (NWMF) 10 yrs ago, a friend and I were playing with my Syncro going over some very steep climbs when we heard a loud bang in the rear and lost all traction (we literally got stuck in the middle of the climb). We didn't have the rear locker enabled, we were just playing with regular VC to see how good it was.

We weren't sure what was going on, so we put the van in neutral and very slowly backtracked the hill till we reached the flat portion to examine the van (using breaks only, we were very careful since a slight deviation could cause the van to flip sideways and roll).

Once at the bottom we were able to determine that the bolts of the rear passenger inner CV had blown-off (they didn't fell, they got essentially cut-off) and the rear passenger axle was loose touching the ground. We still don't know how it happened, our guess was that perhaps one of the bolts had become somewhat loose and the remaining bolts were not able to handle the torque when going uphill (we were using the granny gear in a spirited manner).

Once we determined what was going on, I enabled the rear locker and drove very slowly in "3WD" mode back to the campground (800 feet or so) where we jacked-up the Syncro, removed the broken bolts and installed some new ones (I believe there are 5 bolts in the CV and we found like 10 spare or more among all the Syncro owners in the campground). I still have the same bolts installed in my Syncro.
_________________
87 Syncro Westy EJ25 ("Tardis")

Seattle Meetup at Marymoor (link)
A collection of Simple Useful Mods (SUM) (link)

[Syncro Jael]

So you want a TRIPLE KNOB SYNCRO? Just do it!

After a few years of "the $yncro learning curve" and a lot of miles off-road and on here are my thoughts.

When I purchased my van it was a non-locker. It was great for all around driving and pretty capable off-road in the snow. My son had a rear locker Syncro and the difference was pretty remarkable. So I headed down the deep rabbit hole to convert mine over to a triple knob. I purchased a front locker and decoupler from Daryl at AA. He also suggested a new Sport VC. I also had the transaxle converted to a rear locker. Then I had to get all the vacuum components, dash mount and switches, then run all of the hoses. It was very expensive even back in the day. The wiring was simple because it was already installed in the van.

With a Sport VC I needed a decoupler. After highway driving with the decoupler engaged, the VC was hot enough that the tires would scrub when turning in parking lots and making sharp turns. A simple press of a knob would make all of that go away.

Off road in mud, snow, sand, or loose trails, having good tires and the Syncro AWD with a Sport VC made for a great vehicle. Multiple times I would be amazed at just how capable these vehicles are.

If I got on a trail where the van would lift a tire, that is when the rear locker shined. Now instead of spinning one front and one rear the back end of the van would push through about anything. When the trail looked really loose or steep I would lock the front end. Other than a little lag from the Sport VC I now had a true 4x4 with power to all 4 wheels all the time. Unless the conditions were slick or loose enough the front locker made it extremely difficult to turn the van at all.

I loved the Triple Knob Syncro. The only drawback was not having very low reduction gearing. This would limit you to where you could go. With the limited articulation it was also difficult to go on many trails where I wanted to go. Yes, you could bounce up rock ledges but many times it would get you in trouble trying to keep a line. If it only had reduction gearing, I would still own the van today.

So if you are shopping for a Syncro with (3)three knobs, find one that has already been converted or one from over the pond. Many European vans have a front and rear locker but the decoupler will be an add. Today I am sure it would cost upwards of $10k to convert one if you can locate the parts.

Here is a clip showing the very small lag in my Sport VC. I have never driven a solid shaft, but I am told they are a little more capable in sand. You have to really look to see the rear spin before the front grabs. It is miniscule.


Link


Another clip showing mud and snow. At 3:26 you can see the van stuck in snow.


Link


And some winter highway driving.


Link


Along with a high mountain pass in Colorado. This one I needed more clearance and horsepower.

_________________
1987 Syncro Westfalia Hightop - NAHT
Subaru EJ25 Forged Frankenmotor, Triple Knob.
Jael = (Mountain Goat)

[Klister]

Nice rig!

Unfortunately all the triple knobs for sale I've come across have a solid shaft - no VC.

So, given the choices I'd prefer a normal VC with a rear locker --- if I can find it

[Klister]

[vik]

Maybe another point of view.

I find easier and cheaper to get new VC than front diff with locker.
It took me maybe 2 years to find reasonably priced front locker equipped front diff and it had different R&P.

On decoupler - I do prefer to drive out of town in AWD mode.
But parking - 2WD. You can feel/hear the drivetrain to be ¨tense¨.
_________________
T3 Syncro camper in progress

[Syncro Jael]

[syncro surf]

[Klister]