Comparing decouplers

[Syncroincity]

Here's a good look at the German version, you can see the extra machining that goes into this gear.

I've been running it with a good VC, with the knobs arranged so that all in equals stock driveline configuration. Pull center, it decouples and is 2WD, and the lockers are pull to lock.

I find myself doing a lot of 2WD running, as my slip-yoke driveshaft has a habit of ringing like an alarm bell if I shank a shift or clutch engagement. Decoupling makes it nice and quiet.

I recently got her into full front & aft lock mode attempting to get into an ice-bound parking spot on my street. Didn't make it over the berms, my BFGs showed their weakness on boiler-plate ice. I'm going to have them siped next week.
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'86 Syncro CHC Top AAZ Turbodiesel
'04 Passat Variant 4Mo 5MT

Vanagon Build: http://www.thesamba.com/vw/forum/viewtopic.php?t=466866&highlight=

[IdahoDoug]

Parking while locked would indeed be a challenge! The need to sharply turn the front wheels forces your BFGs to constantly slip if locked. I'd wager unlocked and dropping tire pressures to 15psi would have gotten you further on ice and snow berms. I wish I were there to have fun - sounds like a great time!!!!
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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

[Syncroincity]

[Sodo]

Just getting into decouplers here, so go easy.

If decoupled, can any old towtruck driver pick up a Syncro with a front-wheel dolly? (front wheels stopped, rear wheels on the roadway). Can some decouplers handle this and others cannot?
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'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

[gears]

No, the vehicle still needs to be flat bedded, or the drive shaft removed. Either type of decoupler will fry the tip of the pinion if towing on two wheels. Although the needle bearing is an upgrade, it isn't rated for continuous high speed spinning.

There is a misconception that the "econo" decoupler has a plain bushing instead of needle rollers. No. There is no bushing. It's plain steel on steel .. the same surfaces as before a decoupler was installed.

In normal decoupled operation, these surfaces move in tiny increments relative to one another .. pretty much like two output flanges in a normal differential move only slightly (relative to one another) through a turn. In Syncros with no decoupler, these surfaces never move relative to one another. They are in a fixed position, with all movement occurring within the VC.
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[Emmitt]

If these decouplers are not ment for highway speeds can someone tell my why GoWesty is openly advertising that you can just be pulling the center knob on the fly while driving on the highway????
_________________
1987 Synchro Vanagon GL "Passenger Van".
Boosting RG4, GoWesty Syncro 2in lift Springs, Custom Paint and Interior.

[gears]

Where is it stated that "decouplers are not for highway speeds", or that decouplers shouldn't be engaged while on the fly ?

The only time the needle bearing would be "spinning" would be if the Syncro is improperly towed on two wheels. Any other time, it's merely accommodating tiny, incremental back & forth movement between the pinion shaft and output shaft, when going through left & right turns .. just like the Differential's two output flanges.

My own opinion when comparing the two styles is this:

Both styles do the job adequately.

The "econo" style is overpriced for the parts you receive, when considering that the "German" style includes purpose built engagement teeth and operating sleeve. And of course the German style has a needle bearing, and comes with a brand new output shaft to accommodate that bearing.

The German style could be considered stronger in that the engagement teeth are exactly that .. true engagement teeth formed on a special German shaper cutter .. while the econo style is merely a modified joining sleeve engaging a small portion of the Mainshaft's splines. That said, I don't know that the econo style of engagement has ever failed or exhibited excessive wear in this area. But just because I haven't seen it doesn't mean it hasn't happened.

Yes, I'm presently using both styles on my two vans. For another 10-15%, I'd take the German style over the econo style every time.
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[Sodo]

[gears]

That's a good question, Sodo. The reason the needle bearing can't tolerate high speed spinning for an indefinite period of time is that there is no oil circulation at the needles. Residual oil aside, there is no way to remove the heat. How long will a pilot bearing tolerate spinning without stopping to cool off?

We could always tell which guys sat at the stop lights, in gear, with their foot on the clutch. Noisy throwout bearing, destroyed #1 bearing thrust surface, and toasted input shaft tip / pilot bearing.
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[Sodo]

Hard to know if those clutches were put together without renewing the pilot bearing grease.

Wimmin' never shift into neutral and furthermore hold the car on the hill with the clutch, and their needle bearings survive OK. I've seen a lot of pilot bearings, and dry ones too, even some brass ones. Haven't seen them to be that problematic in clean, dry and no-load situations.

I think a needle bearing will last an ungodly long time in a clean location with just a little lube at no load. The heat in that decoupler, I think is from the shift forks, of which the bigger one of those probably generates 6 times the heat. Although it looks like when decoupled the forks side goes with the front axle? That would be preferable.

Even so I hope to remember to remove the driveline if a 1,000 mile tow on 2 wheels but would not even give it a thought for 50 miles etc. Is it really a purchase consideration? What other details should be considered before purchasing?

Anyone able to put the names of these 2 decouplers? Which one does VanCafe have? AA? GoWesty?

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'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

[gears]

Don't get me wrong .. the needles are FAR superior to steel-on-steel, and they would likely allow "X" number of miles of towing before heat build-up occurs. I'm just not willing to guess (or risk) what "X" is. 5? 50? I don't know. Those needles WILL eventually overheat, though ..

If towing with front lifted, all oil is drained from the nose cone (where the needle bearing is located).
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[Sodo]

I was thinking x miles too

Gotta pick a decoupler brand soon, before my eyes bleed.
_________________


'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

[tim_ha]

Incorrect information removed.
_________________
1986 Syncro Sunroof EJ22
www.subagonsouth.com

[Sodo]

[FrankenSubySyncro]

[insyncro]

Show me this plastic part.....

[FrankenSubySyncro]

It may have been anodized black but it is not plastic.

_________________
Syncronize it!
1987 Franken Syncro (converted 2WD auto)
2004 2.5 SOHC Subaru
F & R lockers, decoupler, SS, 6.17 R&P
Trans Cooler
EMPI race prepped 930 CVs and axles
Bilstein coilover front, rear ProComp MX-6066R shocks, 14" hypercoil springs
30x9.5 15" BFG Muds
Custom skid plates
Nose job (custom front bumper) http://www.flickr.com/photos/subyvanagon/sets/72157624970330925/

[Sodo]

I think the Viscous Coupler would strip a plastic spline the first time you parallel parked. And I know about getting what you paid for I paid for 4 R&Rs of my tranny ---- and I got 4 R&Rs!

Thanks FSuby! What about the rest of the kit? Does the VanCafe kit have a needle bearing or steel bore? Does the switch match my VW locker knob?
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'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

[tim_ha]

Ok, perhaps it was black anodized... I guess I should have taken some pictures.
_________________
1986 Syncro Sunroof EJ22
www.subagonsouth.com

[Sodo]

Now wait a minute!

The steel bore .vs. needle bearing. The shaft will rotate in that bush only during a turn. Lets say you decoupled it and drove in a tight circle. How many turns DIFFERENCE would there be; in one full 360d circle? 2 very slow turns? 5 very slightly faster turns? The relative rotations would be pretty few and pretty slow. I haven't done a single calculation it just doesn't seem like much.

How many turns could this add up to in the lifetime of the car? Most of the turns will be so slow as to be imperceptible.

The only purpose I can see for a needle bearing, is to PROTECT for the situation where the vehicle is towed, front wheels on a dolly. Which I would do, for a few miles. Agreed you just don't "know" how many miles it can take spinning at freeway speeds. I'd want to hear from a reliable source, of one towed for X miles, then inspected. This may never happen.

The needle bearing does add perceived value and satisfy customer demand. I'd prefer it for a level of safety if towed in 2WD.

Are the GoWesty units steel bore? I have not come across a single problem with decouplers wearing out or anything, but I miss a lot of stuff on the forums. Certainly someone else knows if problems have been posted. To me, GoWesty seems to be pretty thorough in their components selection, I'd be surprised if they'd recommend/offer a Decoupler that's not sufficient quality.

Thoughts? I'm more afraid that if GW wants $1,000 for a core that they are so critical of cores that my core could be rejected.
_________________


'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