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Howesight
Samba Member
Joined: July 02, 2008
Posts: 3274
Location: Vancouver, B.C.
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 Posted: Fri Dec 22, 2017 7:21 pm Post subject: Re: Syncro Decoupler on the blink |
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I had a problem recently on my Syncro which has front diff lock, rear diff lock and a decoupler. All my actuators were replaced with new in 2012 and I added the dash vacuum switches for decoupler and front diff lock in 2012. This Van is garaged when not in use, so I did not really expect that the increasingly slow engagement of each of these three devices was due to the actuators. I suspected a vacuum leak and checked every hose and every actuator and the vacuum reservoir also. None were the problem.
It turned out to be two vacuum switches - - the ones installed new in 2012! The 30-year-old factory vacuum switch for the rear diff lock was fine.
The new vacuum switches now on the market seem less robust than the OEM ones. I broke open the worst leaker and examined it. There was no wear observable, so I suspect that the O-rings were of poor material.
Since we have no choice but to buy what is out there, I suggest that you remove the vacuum switch that is leaking (I tested mine with my gauged hand-operated vacuum pump) and try to soak your vacuum switch in ATF (auto trans fluid) overnight. You can use a small piece of vacuum hose to inject the ATF. The theory is that the ATF will expand the O-ring seals in the vacuum switch. I have used this trick in past to revive cruise control vacuum valves that were suffering vacuum leaks.
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'86 Syncro Westy SVX |
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MTV1960
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Joined: March 29, 2011
Posts: 51
Location: Costa Rica
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| Posted: Wed Dec 27, 2017 8:29 am Post subject: Re: Syncro Decoupler on the blink |
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I’ve got the actuator partly remove but it won’t coem all the way off. Is there a pin or screw in the shaft that needs to be removed so it will pull off? Thanks
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86 Wolfsburg Weekender
87 Syncro Westy |
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davevickery
Samba Member
Joined: July 16, 2005
Posts: 2887
Location: Fort Collins, CO
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| Posted: Wed Dec 27, 2017 9:10 am Post subject: Re: Syncro Decoupler on the blink |
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| MTV1960 wrote: |
| I’ve got the actuator partly remove but it won’t coem all the way off. Is there a pin or screw in the shaft that needs to be removed so it will pull off? Thanks |
The actuator for the decoupler is just like the one for the locker shown here. There is a push pin that you have to drive out for the actuator to come all the way off. You can see it in this photo it is almost covered up. Some of them have a short post and some are a 1/2" longer and are easier to get to. If you still have rubber hose over the thing, it will be hard to see.
When you are putting it back together, you can use a piece of 3/4" clear PVC hose, it makes it easier to see where the pin goes. I drill a hole through the clear PVC hose right where the pin goes and use needle nose pliers to get it started. The little hole you drill isn't a problem but you can put a dab of sealer over it if it bothers you.
But why are you taking it all the way off, is it not working, or is the pin in the decoupler not moving back and forth? If the decoupler pin is frozen, you will need to take the whole nosecone off anyway. |
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MTV1960
Samba Member
Joined: March 29, 2011
Posts: 51
Location: Costa Rica
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| Posted: Wed Dec 27, 2017 9:19 am Post subject: Re: Syncro Decoupler on the blink |
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Thanks for getting back so fast. Got the van up on a lift at the moment. I was taking it off to move it and check it out to why it’s not engaging the decoupler. All the hoses are in good shape so not sure what issue is. Was working perfect when parked 5 months ago. Rear works Fine.
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86 Wolfsburg Weekender
87 Syncro Westy |
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MTV1960
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Joined: March 29, 2011
Posts: 51
Location: Costa Rica
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| Posted: Wed Dec 27, 2017 10:07 am Post subject: Re: Syncro Decoupler on the blink |
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Ok so I didn’t remove the actuator totally. I removed the mounting bolts that hold the actuator to the bracket then pulled the part off as far as it would allow and cleaned off the clear tube so I could see what was going on. Then sucked and blew through on of the hoses and the plunger moved in and out and moved the silver shaft part way in so I reconnected everything and drove it but no luck engaging unless the light is bad but I usually can tell if im locked in the front. Doesn’t feel like it. What do you think I should do at this point?
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86 Wolfsburg Weekender
87 Syncro Westy |
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MTV1960
Samba Member
Joined: March 29, 2011
Posts: 51
Location: Costa Rica
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| Posted: Thu Jan 25, 2018 1:33 pm Post subject: Re: Syncro Decoupler on the blink |
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If any one is interested i fixed the issue with the front decoupler not engaging. No problem with any of the vacuum system not working. I removed the actuator and manually pushed in the shaft while slowly turning the front wheels until it locked and moved it back and forth a few times. Reassembled everything and got rid of the clear plastic tubing cover for the actuator shaft that also seemed to be part of the problem as the shaft was hanging up on it. Works awesome now. Now i have what sounds like a CV issue when the front is engaged and under load. clanking when gassed and nothing when coasting or not engaged. any advice here?
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87 Syncro Westy |
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davevickery
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Joined: July 16, 2005
Posts: 2887
Location: Fort Collins, CO
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| Posted: Thu Jan 25, 2018 1:59 pm Post subject: Re: Syncro Decoupler on the blink |
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If you don't put something over the actuator shaft it can get crud all around it and stop working. At least some really thick grease would help. A pice of 3/4" pvc hose works and shouldn't affect movement.
The clanging might be normal depending what it sounds like. The inside of the shaft gets loose and "rings" a bit on some vans. Even aftermarket and donutness shafts do it. It does it more when you are lugging the engine. If that is what it is, no big deal. I once put a rubber donut over a shaft and it quieted it down a bit but it fell off eventually and I didn't worry about it again. |
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MTV1960
Samba Member
Joined: March 29, 2011
Posts: 51
Location: Costa Rica
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| Posted: Thu Jan 25, 2018 3:24 pm Post subject: Re: Syncro Decoupler on the blink |
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The issue i had with the 3/4 clear tubing actuator plunger protector was that it seemed to hang up on the orange rubber boot because the shaft installs offset to the rod. so its not centering in the tube protector. May have to relook at that when i have it over the pit to pull the front axel and do the CV repack. Thanks
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