Syncro rattle grinding whine noise. Bad VC, transaxle, diff?

[T3TRIS]

Hello,

I figured I'd see what you all think these sounds are. I drove our 87 Syncro in tight turns to identify concerning noises. I've been trying to figure out if our VC is shot. We've been stuck in snow and sand with our rear wheels spinning and our front doing nothing... I tried doing the test by lifting the rear and blocking the front wheels with 2x4's but my jack is undersized for this and when I heard a little clicking, decided to abort.
Thinking that our VC is shot and probably leaked into the differential (I read that was a thing), our front diff might be shot too!
Here is a video of our van doing tight turns in each direction both forward and reverse.
There is a loud tin-like rattle when going forward with the steering wheel turned all the way to the right. As soon as I turn the steering wheel back a little, the rattle stops. This does not happen in reverse or when turning left.
We also have a grinding noise coming from the transmission when reversing as you can hear in the end of the video (and in the part where I back up turning right).
Thoughts?


Link


I should add that our muffler has cracked and could be rattling. However it is very tightly connected to its brace with stainless hose clamps and if it were to rattle, it's weird it would only rattle on tight right turns.

Other info: We bought the van 2 years ago and have put about 5,000 miles on it. No drivetrain issues that I can report on except a potentially bad VC (not CV).
No clue about when the last transmission oil change or differential oil changes were done but those are on my list to do ASAP. As I'm learning more and more about mechanics, I realize I should've done that first thing but here we go.
The van had a broken odometer stuck at 275,000 miles when we purchased it. No idea about the tranny history. The motor was already a Subaru EJ22 which needed headgaskets replaced. We ended up having it rebuilt completely. The odometer works again by the way.

UPDATE: The first rattle was the front left dust shield for the disk brakes. I could push it with my finger from inside the wheel, and it'd touch the disk. I just reached in there and pulled it as much as I could trying to bend the metal a little. It seemed to work and tight right turns don't rattle anymore.

[Steve M.]

I'm thinking a bad CV joint, hopefully an inner one.
But I really can't tell anything from the sounds in the video.
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[IdahoDoug]

The loud tinny rattle sound in the first part going forward turning right is no big deal. Sounds like a brake dust shield or something external to the drive train. Not a differential or VC sound or issue. I'm pretty solid on that but interested in other's takes.

The lower frequency growling sound when you back up and let off the gas definitely sounds like a gear issue in the transaxle at the rear. Not sure if its critical or just symptomatic of a 30 year old vehicle in reverse where a lot of trannies make noise. Whether its an issue or just normal would depend on a lot of things.

But I am fairly confident the tinny rattly sound is simply something small that can be fixed by tweaking a thin sheetmetal bit with pliers or securing it.

Any input on last time the transaxle fluid was changed, total miles or other useful stuff would help the experts here.
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[T3TRIS]

[T3TRIS]

[Sodo]

Syncro has helical cut reverse gears, they are quiet and don't whine like straight-cut reverse gears (of some other vehicles).....

Basically "reverse and granny" are "sort of identical" on a Syncro. So compare these two gears, they should sound similar. But the problem could make granny whine too. Your reverse gear sounds like a straight cut gear but it's helical, which should be quiet. That's probably because a bearing is way worn out and the gears have separated off their designed (quiet) tooth contact path. (sorry). I'm going to guess it's the shaft on the smaller gear that's loose. Which suggests the mainshaft bearing is loose (worn out).

It's time to check your drain magnet. Almost any problem that makes noise, will produce an afro on the magnet. Anything that generates an afro on the magnet is worrisome and is grounds to discuss whether that trans needs to be 'stopped' before significant future life is deleted from valuable "No Longer Available" NLA Syncro parts.

Front R&Ps last a long, long time. Front receives less than half of the engine power, PLUS they don't have to operate in the metal barf produced by the transmission (mostly from gear shifting) that rear transaxles run in for tens of thousands of miles (if the owner follows the VW's 'vehicle care' instructions as most people would). Consequently the front R&Ps last a long long time. Your rear could last that long too if run in clean lubricant like the front.

It sounds like your VC is dead though. If your lubricant has been degraded to "some fluid" by mixing with VC goop, it's lubricity has likely been compromised but at least its not a "grinding paste". If the VC is dead, it has not been putting any power through your 'poorly lubricated" front diff, a blessing of sorts. A front "fluid check" and "magnet check" will tell you "something".

Your van doesn't have a "decoupler", right?
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'90 Westy EJ25, NEW oil rings (!) 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
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[T3TRIS]

[gears]

Very fair price for a front diff, even if the VC requires a rebuild. (German does most of the VC rebuilds you see advertised at various retailers.)
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[gtainc]

If you check your front diff fluid level and its over full, feels like honey but smells like rotten eggs your VC has dumped all its silicon fluid into the diff. You can change out the VC by itself, in the rig but understand that the gear oil has been compromised and you probably also have bearing issues. If you'd like some more info and options feel free to give us a call.

[T3TRIS]

[gtainc]

Yes, this is German Transaxle. Give us a call anytime and we can go over options and pricing for both units. I will want to know your tire height in inches, what motor and a bunch more details to fine tune this transaxle to your specific needs and driving style. Hope to speak with you soon.

[T3TRIS]

Well, I finally got around to draining the oil and I have no idea what to think about it.
The first thing that was odd was seeing how the drain plug was sticking out (notice the tool marks too). In the photo below, I had not tried loosening the plug yet (it was very tight).

The space between the exhaust manifold (of our EJ22) and the drain plug made it impossible to use a 17mm allen socket. After trying to weld an M10 nut to a piece of metal and findout out I'm no good at welding, I found a 7/16 rod coupling nut and cut it to 3/4". It fit perfectly inside the drain plug and removal was a breeze (I had already made sure I could remove the fill plug).

Once loosened, I pulled the drain plug out and found out that there is no long magnet on this drain plug as I expected from this syncro transmission. Is this normal?

Therefore I have no idea if we had metal chunks floating around in there. I didn't think about sifting through the oil until it was all drained. I might try to pour it through a strainer to see if anything obvious gets stuck. The oil poured out somewhat golden and shiny. It was hard to capture in a photo, but it looked like metallic paint.

I'm not too sure what to make of this. I have 5 quarts of Valvoline Synthetic 75W80 I'm getting ready to pour back in but I might want to chase a magnetic drain plug first. Ideally I'd put Swepco 210 but couldn't get any in time before this weekend (we have a short trip we're trying to make with the van).

Anyhow, here's another shot of the tool marks on the drain plug.

[dobryan]

Looks like someone removed it with vice grips or a pipe wrench at one time in the past.

That gear oil is very nasty. Bad things have been happening in that trans...
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Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

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[MarkWard]

Vice grips when someone did not have the correct tool. I see red silicone on the bell housing seam. That is not factory. Metal Dustin the oil is signs of something coming apart. I'd not drive it if you are home. Clean lube isn't going to save anything. These are very expensive transaxles to chance a big failure. A simple refresh might get you back on the road. The red silicone and a drain plug with no magnet make me suspect of the unit.
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K.T.24

[syncrodoka]

Have that trans rebuilt, do not pass go, don't collect $200. That fluid says something is quite wrong.
The tranny drain is supposed to sit proud like that but it is supposed to have a magnet and not have vise grip marks on it from a bad PO or bad mechanic.

[T3TRIS]

[Sodo]

[Stuartzickefoose]

Bummer! Wish it was a question when me and kim walked by your place a few weeks ago. Would have been nice to hear it in person!
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Stuart Zickefoose

2011 Jetta Sportwagen TDi 6 speed manual

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[T3TRIS]