Rattle noise in neutral and clutch engaged (not pressed in)

[AZ_CreamPuff]

Well, back from my end of summer blow out trip and the ole girl is going in the garage to start some winter maintenance. Big item to tackle this year is a rattle noise I get when the van is in neutral and the clutch is out. It is more of a "rythmic" rattle that seems to follow the idle speed of the engine. I don't notice the rattle while in gear and no problems with shifting or response. Any ideas?

Edit: forgot to mention 84 manual, and title because of some confusion

[Ahwahnee]

My first thought based on experiencing this on other vehicles is that the throw out bearing is on its way out.

[ng]

[AZ_CreamPuff]

NG. Same deal as you are describing. Depress clutch and it goes away. Let off and it comes back.

[Paulbeard]

I'll verify this when I next fire up the old girl but this sounds a lot like what I have been experiencing recently. Clutch pedal out, rattling: pedal depressed, no rattle. Not news I wanted…
_________________
Currently -> Frida: 87 Tizian Red (mostly) Vanagon GL Westfalia w/ 2.0L ABA conversion
Formerly -> Steward of a 73 Super Beetle (Beater) and 67 Beetle 1300 (Little Max) both names by POs

[Sodo]

A throwout bearing can make noise with the clutch out, and it goes away when clutch depressed. Wish for this.

[Pcforno]

If the noise goes away with the clutch pedal to the floor (disengaged) it is the pilot bearing (input bearing). If it persists with the clutch to the floor then it’s the throw out bearing. If I’m reading your description right, it’s the pilot bearing that’s bad.

[AZ_CreamPuff]

So sounds like it could be a number of things. With a clutch kit I can replace the pilot and throw out bearing. Is it worth it to do the main shaft bearing while in there?

I replaced the tranny fluid last spring and there wasn't an abnormal amount of metal on the plug, and it was doing the same thing at the time. Hopefully no transmission rebuild....

[Sodo]

[Waldi]

Sodo,
your theorie will not become more true if you write it more often.

A gearbox with old gears and shafts do not "make more metal" with new bearings than a new gearbox.

A trans "makes metal" is a normal thing and depends on the age of the bearings and the load you put on it. Not from old gearings or shafts and not from "old" oil.

If we take a "normal" used gearbox, it has "normal" conterminated oil after 100k and still runs another 100k without problems.
If you maintain this box until overused bearings lead to a damage on shafts or gears, you can use this box another 200k without oil changes.
The most importand is to know when your bearings are overused to a point they start to change the position of shafts/gears to a point where they start to take damage/piting. In most cases you can hear this before the damage.

Once more,
the boxes are not beeing destroyed because of "not oil changing".

And yes, you can replace your oil as often you wisch.
It will not hurt your box, but it will also not save it from total damage if you dont change the bearings if needed.

[IdahoDoug]

>>Waldi, I have noticed your thoughts on this before and I know you are a smart guy, so thought I would enter this conversation because it seems I am missing something. I want to understand your view on this so I can think about it.

A gearbox with old gears and shafts do not "make more metal" with new bearings than a new gearbox.
>> I think it would simply because the worn gears would have more wear taking place even with new bearings as the worn gears are not precise.

A trans "makes metal" is a normal thing and depends on the age of the bearings and the load you put on it. Not from old gearings or shafts and not from "old" oil.
>> I feel old oil definitely "makes metal" at a higher rate by carrying abrasive metal into bearing surfaces and gear faces - accelerating wear. A trans "makes metal" is normal, but you can "make MORE metal" with old oil. Yes?

If we take a "normal" used gearbox, it has "normal" conterminated oil after 100k and still runs another 100k without problems.
If you maintain this box until overused bearings lead to a damage on shafts or gears, you can use this box another 200k without oil changes.
The most importand is to know when your bearings are overused to a point they start to change the position of shafts/gears to a point where they start to take damage/piting. In most cases you can hear this before the damage.

Once more,
the boxes are not beeing destroyed because of "not oil changing".
>> I actually feel that "not oil changing" is the #1 cause of gear box wear. Fresh oil produces minimum wear, contaminated oil (that means metal in oil) produces maximum wear.

And yes, you can replace your oil as often you wisch.
It will not hurt your box, but it will also not save it from total damage if you dont change the bearings if needed.[/quote]
>> Agree but if you change the oil more frequently, you will change the bearings LESS frequently, right? I am having a hard time that it seems you do not accept that fresh oil in a gear case is a good thing, and that it reduces wear and extends component life. Are you saying you do not accept that, or perhaps I am missing something and you are only saying it is not a cost savings? Or that you'd prefer to wear out bearings and change them instead of change the oil.

>> I sincerely am trying to understand because I respect your opinion and feel that I am missing something here.

Doug
_________________
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

[MarkWard]

It depends where the metal is coming from. While the synchronizer ring is brass, it only aligns the slider hub and gear face. So, every shift is metal on metal. Manufacturers put magnets even in automatics to collect metal particles. Its all part of normal wear and tear. A failing bearing is another problem all together.

For the noise, clutch out had me thinking. But another possibility is over time the rotational springs in the clutch disc can wear. They will actually rattle enough so that you can hear them idling with your foot off the clutch. This was more pronounced on diesel clutches, but the springs do wear on all discs. When you have the clutch in your hands, check the springs, they should be snug.
_________________
☮️

[Sodo]

[Jake de Villiers]

[AZ_CreamPuff]

Thanks for all the input guys, I really appreciate it. I'm going to do a clutch rebuild kit likely from VC. Hopefully that solves the problem. I'm sure you will be hearing from we when that process goes down. Luckily for me I live super close to Arizona Transaxle exchange if it doesn't work. Unlucky for the wallet I suppose.

Things I should do while in there?
1. Rear main seal
2. Repack CV's
????

Or should I just take it down there now. Hmmmmm.

[Sodo]

[AZ_CreamPuff]

Sodo. Will do, I'll try and get to it this weekend and will post some pics of the results.

[Waldi]

>>Waldi, I have noticed your thoughts on this before and I know you are a smart guy, so thought I would enter this conversation because it seems I am missing something. I want to understand your view on this so I can think about it.

Yes you do

A gearbox with old gears and shafts do not "make more metal" with new bearings than a new gearbox.
>> I think it would simply because the worn gears would have more wear taking place even with new bearings as the worn gears are not precise.

If the gears/r+p would not be prcise theay should be changed or they would be destroyed in short time. They are only not precise if the change position due to worn out bearings.
The only case where the metal comes from gears is if the synchronizers are worn out and the driver ignors ist and hammers the gears in. But this is not metal from a normal running box.

A trans "makes metal" is a normal thing and depends on the age of the bearings and the load you put on it. Not from old gearings or shafts and not from "old" oil.
>> I feel old oil definitely "makes metal" at a higher rate by carrying abrasive metal into bearing surfaces and gear faces - accelerating wear. A trans "makes metal" is normal, but you can "make MORE metal" with old oil. Yes?

Hard to argue against "feelings and believings" with fakts and practical experiance.


If we take a "normal" used gearbox, it has "normal" conterminated oil after 100k and still runs another 100k without problems.
If you maintain this box until overused bearings lead to a damage on shafts or gears, you can use this box another 200k without oil changes.
The most importand is to know when your bearings are overused to a point they start to change the position of shafts/gears to a point where they start to take damage/piting. In most cases you can hear this before the damage.

Once more,
the boxes are not beeing destroyed because of "not oil changing".
>> I actually feel that "not oil changing" is the #1 cause of gear box wear. Fresh oil produces minimum wear, contaminated oil (that means metal in oil) produces maximum wear.

So how you explain with your "feelings" that a box can run 200k without oil changes and still good parts inside ? Change bearings and run it again 200k. And again. And again ?
While you can worn out the bearings even in a stock engine within 100k if running steep up and downhill in 1st ?
Number one of wear for the bearings is load.
No worn out bearings, no broken other parts (which has nothing to do with oil) no damaged gearbox parts (r+p, shafts, gears).
No matter if old oil or new oil.


And yes, you can replace your oil as often you wisch.
It will not hurt your box, but it will also not save it from total damage if you dont change the bearings if needed.[/quote]
>> Agree but if you change the oil more frequently, you will change the bearings LESS frequently, right? I am having a hard time that it seems you do not accept that fresh oil in a gear case is a good thing, and that it reduces wear and extends component life. Are you saying you do not accept that, or perhaps I am missing something and you are only saying it is not a cost savings? Or that you'd prefer to wear out bearings and change them instead of change the oil.

>> I sincerely am trying to understand because I respect your opinion and feel that I am missing something here.

What is the goal ?
To drive the box to total damage as long as possible ?
Or to avoid a total damage ?

If the first, ok, the bearings may last 20k longer under same load with cleaned oil, and you get broke on the street 20k later, due to another broken part that has nothing to do with the oil, or just because your bearings were worn out 20k later and you have ignored it.

As for metal dust grinding.
Take the stuff from the magnet drain plug and try to grind hardened metal with it.
You will be not succesfull, and thats why all parts exepts the bearings which run under load, are not worn out in a box running 200k in its oil.
Isnstall a worn out main bearing with oil cooling and filtering and your box is trash after short time.


Cleaning/changing oil is a waste of money and time.
As many other things too, we do on out vans.
If you want to check the drain plug, let the oil out, leave it over night alone, use it again. If it is the first original filling, ofc it makes sense to change it for new, but not full synthetic. But if the box has far over 100k its wasted money.
What to do to avoid a total damage of the gearbox, was told by me before


[/b]

[Waldi]

[Sodo]