Is this noise normal? On my 86 syncro, transaxle makes flapping

[pyite20v]

Please watch this 10 second video. When I rotate either rear wheel, there is a flapping noise from the transaxle.

Rear of the van jacked in the air, front wheels on the ground. Decoupler de-coupled.

I dont notice the sound while driving.

Rebuilt Porsche 944 Turbo axels and CV joints.


Link

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86 Syncro Westfalia EJ25 OBDII
Nevada City CA

[16CVs]

Mine did that, sounded like it had something stuck to the tire, turned out to be as bad ring an pinion.

Stacy
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1987 Syncro Westfalia Triple knob (bastard)
1989 Syncro Tristar Triple knob "Swedish"
2013 Jetta Hybrid a true "Zwitter"
Samba member # 14980
Call anytime number 650 722 4914 .
Keep Your van running and upkept tastefully for the love of the hobby.
Don't let your van end up in an "abortions" thread.

[pyite20v]

Thats exactly what I didn't want you to say. It was rebuilt a year ago by AA so hoping its something else.
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86 Syncro Westfalia EJ25 OBDII
Nevada City CA

[Bassyaks]

Do you have a locker in the rear?

[pyite20v]

No locker in the rear.
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86 Syncro Westfalia EJ25 OBDII
Nevada City CA

[pyite20v]

Is this safe to drive, or is it going to explode on me on the hwy? Was planning on taking the Ms to Yosemite tomorrow.
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86 Syncro Westfalia EJ25 OBDII
Nevada City CA

[16CVs]

I wouldn't drive it until you figure out what is bad. If it is a bad R/P or anything else you are introducing metal shavings into the oil which feeds the bearing.
Hopefully it is not a R/P, but you'd better figure it out now.

Stacy
_________________
1987 Syncro Westfalia Triple knob (bastard)
1989 Syncro Tristar Triple knob "Swedish"
2013 Jetta Hybrid a true "Zwitter"
Samba member # 14980
Call anytime number 650 722 4914 .
Keep Your van running and upkept tastefully for the love of the hobby.
Don't let your van end up in an "abortions" thread.

[Wildthings]

Is the tranny in gear so nothing is turning inside the box but the spider gears? Are the two rear wheels just turning in opposite direction from each other when the noise is occurring? If these things are true then likely you are just hearing the spider gears meshing and have nothing to worry about.

[pyite20v]

The tranny is not in gear, so its just the one wheel turning. I didnt try turing it in gear so I dont know if the noise is different. I cannot hear anything while it is on the ground.

Could it just be spider gears? It doesn't sound metalic....
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86 Syncro Westfalia EJ25 OBDII
Nevada City CA

[pyite20v]

Jacked it back up and put it in gear, and now there is no noise.

No noise when not in gear either. Could it have fallen back in place somehow?
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86 Syncro Westfalia EJ25 OBDII
Nevada City CA

[Wildthings]

The answer would be "I don't know, or at least am not sure" If your pinion bearings are going, the ring and pinion could run out of alignment and cause noise.

FWIW, I have had pinion bearing problems on both automatic and manual Vanagon boxes.

[Sodo]

If you've busted a ring gear tooth, there's a pretty good chance the broken tooth is stuck on the drainplug magnet. If you have a broken tooth, you CANNOT drive it. Except perhaps gently downhill for a few miles, I've heard of that being done.

Was that a 48hp Diesel I heard?..... If it's big engine methinks you need a habit of checking your drainplug at the drop of a hat, Syncro trans is getting way to expensive to treat casually.
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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

[pyite20v]

There was no engine on in the video, I was just turning the tire by hand. Now there is no noise. Drove it to town and back last night and there was no noise.

Could it have just been the spider gears in a weird position from jacking the car up on one side or something?
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86 Syncro Westfalia EJ25 OBDII
Nevada City CA

[Syncro Jael]

^^^^
Agreed.

Check the magnet before you drive it again.

These boxes run very quiet so a noise like that is not good. But really strange that you do not hear it while driving. You could purchase a cheap scope and take a look inside the fill/drain ports to check some things out.

I have never had a transaxle heal itself after it starts making noises.


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

[Sodo]

[gears]

I'd agree that's it's something with the spider gears, and that it's FAR from a normal sound. It could be that the shim on the backside of the side gear(s) has worn into the housing for some reason.

You didn't hear it driving into town because the spiders only move (relative to their matching side gears) when going through turns .. and even then they don't move much. Your noise test made the spiders WAY more active than they are in actual driving.

Please don't be lazy and just shrug this off .. show us your drain magnet.
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aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[crazyvwvanman]

I wondered if the noise was perhaps the decoupler not 100% pulled into disengagement. The frequency of the noise seems a little too fast for spider gears. The decoupler rotates with the pinion shaft and the pinion shaft rotates at about 5 times wheel speed. Could you tell that the noise wasn't from the nose area of the tranny where the decoupler lives?

Mark

[gears]

I think you're close, Mark .. I'm now thinking it was actually the tips of engagement teeth of shift sleeve and gear barely contacting, the result of not being in true neutral.

[Sodo]