Syncro - 1 knob, 2 knobs or 3?

[jlrftype7]

[Howesight]

My rig started life as a tin-top Syncro with factory rear locker only. When having the transaxle rebuilt, I decided to have the front diff machined to accept a front locker and added a decoupler. I did the front locker install because of memories of several times climbing very steep muddy grades with a Toyota 4-runner with a rear locker, but no front locker. The one guy in that group with a front locker got up the hill. Some "redneck" front lockers were installed on Chebby/Ford 4x4's with a stick-welded diff, (using hub locks unlocked on the highway) and those rigs also got up the hills.

Knowing what I now know, if I had to do this all over again, I would probably not install the front locker. There are no real negatives except cost as it is totally "plug and play", but I have very rarely had to use the front locker.

On the occasions that I have used the front locker, it was, realistically, in places I had no business going in an antique with no winches and no friends along to assist. The impact on steering, even in the slipperiest mud, is dramatic. You really need to hold the steering wheel tight when engaging the front diff lock. For those occasions when one front wheel is off the ground or otherwise slipping, the front diff lock is excellent.

For this same reason, I cannot see any good coming from a Peloquin or similar Torque biasing front diff because once one wheel is off the ground altogether, the TBD cannot bias the torque. With careful application of brakes, sure, the TBD starts to provide torque to the slipping wheel, but I hasten to add that the hairy conditions that require a front diff lock are usually so hairy that you will not have the ability to apply brakes "just right" to force the TBD to work.

So . . . that is my data point and I hope it is of assistance to the OP.
_________________
'86 Syncro Westy SVX

[Sodo]

Excellent real life feedack.

[tjet]

Here's a good video on the benefit of air lockers. I'm curious to see how a torque biasing diff would behave in a similar situation. If you google "Detroit Locker in front", you will see some people with Jeeps that put them in the front.


Link

[elizer]

I used to have a 2016 jku Rubicon hard rock. It comes standard with front and rear diff locks. They really really help in many different situations. But I would never be in any of those places with the westy. Well I wont say never. My westy is at Fas it is getting the 2nd and 3rd knob. I only did it because I had the front diff rebuilt and just said the hell with it.

[BavarianWrench]

I have a triple knob story. I was so excited to finally have the holy grail, Three Knobs.
I start up a fairly steep snow covered hill. Open diff, rear wheel drive. I notice it just starting to slip and engage the driveshaft quieting the pans that had started to rattle. Onward and upward. The grade increases and the pots and pans rattle a bit as the tire loosing traction hops. I lock in the rear diff and continue to climb. I can not believe how well the rig is pulling. Slight turn, and another increase in the grade. The pots rattle, and I engage the front diff quieting them. Once again the tires are pulling me up with no lost energy bouncing a traction-less tire. I'm in awe as the pitch increases and I remain climbing.
Then it happens. I find the limit, and the van starts to rattle the pans again. As the tires slip I realize my fun is over. I have reached as far as I am going to climb. The pitch had once again increased.
I cover the brake. Then gently apply it as I depress the clutch. At that moment I realize, I'm in a must make it to the top situation. I didn't catch that in time. There was no traction to hold the wheels locked by the brakes. I almost totaled my van as it accelerated down the face of the mountain side searching for level. I did some pumping of the brake and some crazy attempts at steering. I was really just lucky. the Van slid down the mountainside. Part of the slide was off the trail. I missed trees, some by steering, others by luck. A triple locker can get you out of a mess. It can also get you into some very dangerous territory. I want another one.

[tjet]

Good story. What's your ring & pinion gearing and tire size?

[BavarianWrench]

[tjet]

Was that the one you drove up Manhattan Beach Blvd on that clutch-smoking grade from the pier?

[BavarianWrench]

For the OP and keeping on topic. The more knobs the better and while we are on a little side note. Apologies to the OP. Purchasing a Syncro from Europe is a good way to get into a triple knob for less money. The front diff option was not available in the US market. Yet it was somewhat common in Europe. Yes that Reimo is the one I brought over.

[vanagonjr]

Less we forget.

[danfromsyr]

in the north east everywhere I've driven off road
i've encountered a corolla or a camry

in a Syncro

the 1st knob is the rear differential and can be handy from time to time, but not as often as you'd think. you'll use it more to keep it 'exercised' and ready than in actual operation/use. yet 85%+ of north american market syncro come with a rear diff lock.

the middle knob is to enter 2wd mode and only useful for when you have mis matched spare tire.

the 3rd knob is for the front diff, and well it's nearly never used, thought of or practical.


all AWD/4WD are capable of getting stuck far enough from a main road to cost much more when you have to call in a 4wd tow/recovery.

I don't subscribe to the take it out and bash it like it's a jeep mentality. that's what jeeps are made for, rugged disposable fun.
_________________

[Syncro Jael]

[flomulgator]

Everyone salts now. Washington State, formerly a salt-free paradise, salts the passes all winter long and the city of the Seattle looks like the Utah salt flats half the winter. Most of the west already followed suit, I think OR is the only holdout. Midwest/NE is more continuous salt coverage than the West, but salt everywhere is the new reality; I say its better to adjust than avoid. Wash the underside of your syncro at least monthly during the winter (which is easy with a wand due to the ride height) and do one of those treatments in the summer. I had your exact car (a 2008 328xi wagon, 6MT) that lived in the midwest before I owned it and it had fist-sized clumps of re-precipitated salt behind the plastic underbody panels because it was never cared for. It's all in the maintenance!

For snow you don't need knobs, they only help if you're not moving. Above about 20 mph a locked rear in the snow becomes a liability. You can fake a rear locker if you are truly stuck by just pulling on the e-brake handle. I have done this on my syncro stuck in the snow with a frozen rear locker and it worked about as good as if the locker had worked.

As others have said, the ultimate setup for snow is either LSDs or peloquins front and rear. That would be the traction equivalent of a Subaru STI.


As an aside: I hear you on the BMW wagon. Even doing my own maintenance with non-OEM parts from Pelican Parts, etc..., it was still pricey and not a very reliable vehicle. Kinda like a Syncro! It was a beast in the snow though, better than a Subie Outback.....Kinda like a Syncro!
_________________
She's built like a steakhouse, but she handles like a bistro!

[WestyBob]

Oregon has a long history of follow the leader rather than thinking for itself so to that extent it pretty much salts certain mtn. passes now, uses lots of chemicals elsewhere, and we are gravitating toward a total salt environment in parallel to Cali and Wash.

Portland in particular 'sneaks' in their salt and metal feasting chemicals all winter to handle those two or three days of one inch snowfalls that paralyze the city. Over time this has largely been due to huge migrations of people from elsewhere where salting was the norm hence their perpetual complaining about the absence thereof until more recently. Truckers in particular complained about coming down through the Columbia Gorge without salt which is now 'kinda' in use.

I crossed the pass between Cali & Ore on I-5 many years ago where we were plowing through some slush with lots of brown stuff in it. Later I noticed my westy undercarriage was beginning to look a little rough (rusty).

[kguarnotta]

Beautiful pictures Syncro Jael.

Am I correct in the idea that the knobs actuate the locking mechanisms through pneumatics?

A few responses here make me think the peloquin differential is installed in the front, but when I was first reading about them- I assumed all the references were for installing them in the rear. Did I misunderstand something?
_________________
-Kevin
Lincoln, MA

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

[dobryan]

AFAIK a Peloquin TBD can be installed in the rear and front.
_________________
Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
https://www.thesamba.com/vw/forum/viewtopic.php?t=620646

Building a bus for travel in Europe (euroBus)
https://www.thesamba.com/vw/forum/viewtopic.php?t=695371

The Western Syncro build
https://www.thesamba.com/vw/forum/viewtopic.php?t=746794

[Sodo]

[kguarnotta]

Thanks Sodo.

Is this correct - all syncros from the factory have the set up prepped for a 3-knobs (ie wiring and sensors) to add a knob(ie locker, decoupler etc) you need to then add a physical component or change the transaxle, right? Is that what you mean by spend the $4,000 to add the capabilities of the multiple knobs.
_________________
-Kevin
Lincoln, MA

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

[flomulgator]

Incorrect.
Some syncros were sold without any lockers, these lack the wiring, vacuum plumbing, and dash panel altogether. These syncros, just like the “knobbed” locker syncros, would benefit from the installation of mechanical LSDs/TBDs in the front and rear, but if you want to “add a locker” you would have to add-in all of the stuff mentioned above. For this reason, lockerless syncros are often cheaper as they are not as popular with the crowd that buys syncros for off-rod purposes. Which you may benefit from if you don’t need lockers.
_________________
She's built like a steakhouse, but she handles like a bistro!