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Discussion Starter #1
Hi guys, I have a '97 Chevy S10 with a manual 4.3 V6, which had a new driveshaft and clutch plate put in last year (apparently). I've only had it 8 months, but in the last few weeks has started making a fairly quiet/subtle crunching kind of sound (sounds like somebody is stirring a bowl full of ball bearings) only when the clutch is depressed at very low speeds, and it is getting harder to get it into gear, particularly 1st and 2nd. When the truck is stationary, it also makes a little donk noise when pushing/letting go of the clutch pedal - whether its in gear or not. I also just remembered that if you're doing say, 40mph, and you try to put it in too high a gear, like 5th, it will make the same kind of 'stirring a bowl of ball bearings' sound, until the revs pick up a bit and the engine is happier in that gear.

At first I thought it could be the gearbox, because the sound is kind of like the sound of two gears meshing loudly, but after a bit of research online it appears that it might be a clutch bearing.

The truck also makes a little donk sound when setting off, in forward and reverse, so also points towards it not being the gearbox, or maybe it does, I dunno, I'm not too knowledgable about the transmission side of engines.

I only use the truck at weekends, and usually only evenings when all garages are shut, so thats when I remember to sort it out, and now I don't particularly want to drive it anywhere with the risk of it going seriously wrong somewhere.


Can anybody tell me what the problem might be, based on my description? The sound is too quiet for me to record on a phone with the engine going and upload for anyone to hear, but if anybody is near me (Putney, SW London), or knows anybody close who could diagnose it, I would be prepared to pay anything up to a few beers. Thanks.
 

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It does sound clutch related. Maybe when the clutch was replaced they only did the plate and not the full assembly.
 

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Discussion Starter #4 (Edited)
Ok. Is the release bearing the same as the throwout bearing, which is on the gearbox side? And then the other one on the flywheel will be the main/pilot bearing?

Why do you think the clutch isn't disengaging properly, is it because of the sound when the clutch is down?

Would the donk sound just be the play in the clutch now on the shafts?
 

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Release bearing is under no load until the clutch is depressed. Clutch engaged will be a grinding grumbling and disengaged will be a more of a loose rattle. The clunk into gear implies either the syncros are not meshing / matching gear speeds or drive isn't full disengaged. If the clutch is juddery and jerky odds are springs in the plate are gone too. Pull the gearbox out, inspect release bearing, friction plate and pressure plate, odds are these are fucked. Drain the oil from the box, check and see if you have any swarf or broken teeth etc. If you find knackered clutch odds are this was your problem, if not, get the box looked at
 

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Discussion Starter #7
Thanks for your help, WB54. I will take it out, and now I know what to look for. So is the release bearing the same as the throwout bearing?

Is the thrust bearing the same one? And can't that be replaced on it's own, rather than replacing the whole clutch, Ranchero?
 

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Release, throwout and thrust bearing are all just different words for the same thing, if you had a new clutch recently then you can change just the bearing. When the gearbox is out remove and check the clutch for wear of the friction material, check the clutch cover for scoring on its surface and wear/damage where the bearing runs against the clutch cover.
The pilot/spigot bearing is in the end of the crankshaft and supports the nose of the gearbox input shaft. It will either be a brass bush or a small needle roller bearing and it's important to check this for wear. As the truck is nearly 20 years old and probably has some miles on it I would change this anyway although they can be a bitch to remove
 

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Make sure you put the right lubricant on the input shaft and in the spigot bearing!

Ask me how I know!!

Mind you, it may not have a spigot bearing...... Can't remember which car, but one didn't have one as the clutch 'needed to float'.
 

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Discussion Starter #10
awesome, thanks for your help everyone. New bearings it is! (and a whole check of everything while im down there)
 

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"The truck also makes a little donk sound when setting off, in forward and reverse, so also points towards it not being the gearbox, or maybe it does, I dunno, I'm not too knowledgable about the transmission side of engines."


This sounds more like play in the propshaft, U/Js or diff, although with the other noises I wonder if the clutch pressure plate is loose? If the seller said it had a new clutch fitted then maybe the installer didn't finish the job off properly - either way it sounds like you will need to drop the prop, gearbox and bellhousing to look.
 

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Discussion Starter #12
Yeh, I will obviously be removing the prop and gearbox anyway so if theyre just loose, they will be refitted correctly and remove any issues there. I'm just going to buy new bearings beforehand, then take it all off, inspect it all, fit the new bearings and then see if it needs anything else.

Thanks
 
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