Possible wildlife in CVT somewhere

Post by **Essex1** » 19 Jan 2007 07:39 pm

Hi guys,
Have a problem with the CVT - when i let off the throttle its chirps like a grasshopper has got stuck in it somewhere. Its very annoying. Its definitely transmission as it squeaks when stationery when the car is in gear/foot on brake/very light thottle, i.e about to engage. Really noisy on the move and can hear a rattle when i let off as well, though this may just be the clutch plate making a legitimate noise. It did have a clutch fairly recently (>1000miles ago) and i'm wondering if this may have something to do with it? Its not done many miles since fitting so i didn't think it was quite time for a reshimming yet? Starts terribly too, but thats another story.....
Any pearls of wisdom greatly appreciated

Post by **pettaw** » 19 Jan 2007 08:17 pm

The squeaking is most likely the belts. When they're cold they can squeak. The replacement belts are harder than the original ones and therefore squeak more before they're warmed up.

I dunno if they squeak more when they're worn or not, tbh, but its a reasonable guess.

The clunking I can't really explain except they can judder a bit when coming in and out of gear when the revs are low.

Post by **Essex1** » 19 Jan 2007 08:34 pm

Not sure its the belts cos it only does it when you let off the throttle whilst going along, but its doing it all the time hot or cold. Seems to be worse cold. Is that belt type symptoms??

Post by **Essex1** » 19 Jan 2007 08:35 pm

Sorry I meant worse when hot...

Post by **pettaw** » 20 Jan 2007 08:49 am

I agree it isn't the standard symptoms of belt noise, but then again stranger things have happened and tbh I can't think of anything else that would make transmission squeak.

I would get the covers off and check the belts tbh, also check the pulleys to make sure they're nice and smooth all over and have no rusty bits on the cones.

Post by **SteveP** » 20 Jan 2007 12:49 pm

I hate to throw a spanner in the works, but could these (or some of the) symptoms not be prop related?

Website · Post by **antiekeradio** » 20 Jan 2007 02:55 pm

no belt noise. might be exhaust fixing with a little movement, or else the driveshaft bearing!

if the bearing in the bellhouse was not replaced together with the clutch, that would have been asking for this exact same problem, actually....

Post by **petefarrell360** » 20 Jan 2007 08:30 pm

Yeah, I'd agree that it's not belts, they only really make a noise when moving away from standstill, and in theory should be gripping better under the different forces when slowing down.

You can hear a sort of clunk noise as the clutch engages or disengages, more so I suppose if it's a hard heavy stop from speed quickly as I spose the belts are still helping to slow the car down, then the clutch disengages and the sudden change in forces makes the noise. Or at very low revs when moving about where it's on the borderline of engaging and disengaging due to the revs, approx 950 rpm up to 1100 rpm from memory. So fluctuating above and below this can make it engage and disengage a few times.

If it's when in gear, but still not moving, or when moving, slowing down, light throttle etc, I'm with antiekeradio that's it the bearing. We replaced mine when we did the clutch to be safe, but the original should have been ok on 10,500 miles, sadly the clutch wasn't.

Pete

Post by **Essex1** » 20 Jan 2007 09:55 pm

Def sounds like a bearing or metal rubbing somewhere (and getting worse quite rapidly). I replaced the thrust bearing when I did the clutch - is there another one I missed???

Post by **pettaw** » 21 Jan 2007 01:32 am

We didn't replace that bearing though Pete

I do agree it sounds a strange noise though

Website · Post by **antiekeradio** » 21 Jan 2007 03:49 pm

Essex1 wrote:Def sounds like a bearing or metal rubbing somewhere (and getting worse quite rapidly). I replaced the thrust bearing when I did the clutch - is there another one I missed???

When overhauling a manual clutch the thrust bearing is important to change. On a CVT clutch it hardly ever needs changing

the other 2 bearings, (located at either end of the clutch shaft, being at center of flywheel, and at the tip of the bellhousing) are far more important to change.

the bearing in the flywheel has a 'tolerance ring' which clamps the inner bearing ring on the clutch shaft (enabling assembly without brute force but disabling any movement/rotation between shaft and inner bearing ring) it is a good idea to change the tolerance ring together with the bearing (single use)

the bearing at the tip of the bellhouse has to do its work in a very difficult environment. at both sides of the bearing, there is moist and dust, which slowly penetrates the sealing caps. if you dismantle the clutch shaft, the bearing is tilted in a way that cannot happen when it is mounted. more often than not this works loose some grit, which starts to get rolled around inside the bearing.

bearing gets shot in no time...

a better solution would have been a open cage bearing with rubber seals at either end, but this would have cost a few quid more...

Post by **Essex1** » 22 Jan 2007 12:17 pm

Cheers guys, sounds likely its one of the bearings, i didn't think the little idler one on the shaft was upto much when i changed the clutch, but didn't have time to get a new one....