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Just helped somebody put a M41 into their car, and got it running. At idle there is a noise coming from the transmission, but the noise goes away when the clutch is disengaged (clutch pedal is depressed).
Is this a problem with the clutch or transmission?
Paul
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I agree, Cameron might be right.
But having met you, Paul, I expect you put in a new throwout bearing.
Tranny input shaft bearing could be the culprit, but those rarely go bad.
Tranny layshaft bearings do go bad. And that's what I'm going with. Laygear always spins. It spins with no torque applied in neutral, or in 4th gear. Torque makes the noise go away... so...
Is the noise there when driving in 4th gear?
Thanks to Vclassics.com for the pic.
--
-Matt I ♥ my ♂
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And I should add.. when I had similar issues in my 1800, I babied it for a long, long time. But, one night delivering pizza, I got frustrated. Dumped the clutch at near redline (couldn't find an address :) ) and heard a loud crunch, then... no 1st gear.
Inspection revealed all the 1st gear teeth on the lay-gear to be broken off. The bearings had worn so badly that the gear was sitting low on the layshaft (also heavily worn), and the teeth were not making good contact with those on the output shaft, and my stupid driving caused it to break into little bits.
That laygear now serves us faithfully as a candle holder.
Change the tranny fluid, check the old for glitter, and baby it for now.
--
-Matt I ♥ my ♂
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Pulled the tranny, and there was definitely a roughness to the tranny when the input shaft was spun.
I have several M41s, and switched it out with another one. No noise from the second tranny.
Paul
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Throwout bearing.
Cameron
Rose City
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I'm sorry but Cameron is wrong about targeting the release bearing. When the clutch pedal is pressed is when the release bearing comes into play and that is when a bad one will make noise. The noise coming from the transmission in question is most likely the input shaft bearing. -- Dave
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I might be wrong. There are other things that might give the symptom described. I might be right, too.
In my own cars and in customers' cars I've seen a number of instances in which a worn throwout bearing makes noise - usually a muffled, cyclical rattling - as the parts get sloppy and no longer fit together nice and snug. When you push the clutch pedal toward the floor, the rattling loose throwout bearing is compressed, and it quits rattling. It gets quiet. The opposite of what you describe, Dave.
If you try a search here on the Brickboard you'll find references to exactly this. Or you can try google or bing and find videos that demonstrate it pretty well. I haven't seen any Volvos in those videos, but clutches are pretty standard things that tend to degrade in similar ways regardless of the brand.
You might be right about that input shaft thing, though when I've had trans bearings go south on my own 122, the bearing noise changed pitch as road speed changed.
Did I piss you off or something? The tone of your note comes off a little hostile.
Anyway - maybe I'm wrong, maybe I'm not. We can't make any assertions about that just yet. The throwout bearing isn't a bad guess, is easy to evaluate as soon as the transmission is out of the car, is cheap to buy and simple to replace, and is certainly the first thing I'd check.
Best,
Cameron
Rose City
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I agree with you . yes the bearing is not under load when the clutch pedal is up but I have had a few noisy Throwout bearings that growl and then get quiet when depressing the pedal.
--
'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.lyse.net/brox/TonyPage4.html http://cleanflametrap.com/tony/
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Cameron wrote--"Did I piss you off or something? The tone of your note comes off a little hostile."
Sorry if you took it that way--it was not intended to convey that. It also occurred to me later that maybe we actually agreed in theory--if the OP words were misinterpreted (something I've been guilty of at times) in his description of engaged/disengaged--although he did seem to take pains to clarify his meaning. These things can get confusing as engaged/disengaged can refer to two different things depending on whether we are talking about the clutch or the release bearing---that is--when the release bearing is "engaged" the clutch is "disengaged" and vice-versa. But it does appear that you understood the OP's words as he intended.
From my own personal experience a noise (the OP didn't describe the noise) coming at idle/neutral as a bearing "roar" has led to transmission repair or replacement. -- Dave
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Ah, good. Glad I haven't upset the apple cart by mistake. Thanks.
Good point, too, re: confusion related to engaging versus disengaging the clutch. For the sake of clarity I find myself avoiding those terms and simplifying descriptions into "with the clutch pedal pressed down" or "with the clutch pedal released" kinds of statements - otherwise a quick conversation about what to do or what's happening becomes a longer tutorial about proper use of terminology, which will become irrelevant for most Volvo owners as soon as their noise goes away.
You've probably heard people telling others how to drive a manual transmission say things like "give it more clutch" and then witnessed the instructor's frustration when the notion of "more clutch" is interpreted exactly backward.
Based on the most recent post, it looks like you were dead right about this one - it was the transmission. I do believe, still, that determining symptoms described as these were that the only way to know for certain was by removing the transmission and getting a look in there. Bottom line - the car is on its way to being fixed, which is the whole notion behind the brickboard. So that's good.
Best,
Cameron
Rose City
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Not to say that it couldn't be the throw out bearing, especially if the slave push rod clearance is a bit big or the clutch arm spring has popped off or is missing. The pilot bearing could also be a suspect.
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In Cameron's defense, I've had a throwout bearing with those symptoms. But yes, there was obviously an adjustment issue as well since the throwout bearing was not fully disengaging.
On a few used M40/M41 gearboxes I've installed it's been bad layshaft bearings with those symptoms.
Moral of the story, I take apart and inspect prior to installation now.
--
"Differences of opinions should be tolerated, but not if they're too different" - Sharon Craig
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