Bouncing Clutch Pedal

[KenEvans]

Has anybody experienced on the K series a clutch pedal that taps you under the foot firmly and rapidly at revs of, say, 5000 or more? I find it most disconcerting and annoying!.

 

Having had a release bearing already fail once at 6000 miles with it basically falling apart I'm concerned that this might be warning of the same thing happening again.

 

The clutch feel and adjustment seems ok to me but there's something going on down there.

[oilyhands]

Ayup Ken,

 

The normal causes are excessive crank endfloat (which is rare on the K), lack of clearance between the thrust bearing and the clutch diaphragm, or a disintegrating / detached / sticking thrust bearing. Perhaps the bearing is coming away from the carrier or getting wedged on the end of the 1st motion shaft nose.

 

Oily

[KenEvans]

Ayup Oily

 

Timed the new engine 0-60 this afternoon with the help of son, stop watch and reminder/instruction about parallax error - 4.2 seconds :-) 0-100 next when the road is quieter.

 

Regarding the points you raised about the release bearing. It's only done 1500 miles following replacement of the last one and it went onto the nose of a new 6 speed box so in theory it's something simple like lack of clearance (which is the impression I have). I slid the bearing onto the shaft dry because there's no specific instruction to the contrary in the Caterham manual.

 

I assume this is normally sorted by judicious use and adjustment of springs at the pedal?

 

 

[ant]

Ken

 

Yep, suffering from the exact same thing. Mine make's a godawful noise as well unless I keep my foot resting on it firmly enough. It appeared straight after I had my pedal box moved.

 

The car's going in to Caterham for a service tomorrow, hopefuly to be fixed ( 'cos I am mechanically incapable). If they give me a reason for the problem and I understand it I'll report back.

 

Ant.

[KenEvans]

Hello Ant - I look forward to heaing how you get on. I'm interested that it started after the pedal box was messed about with which suggests that it might be fixable with suitable spring adjustments.

 

Ken

[Peter Carmichael]

There is no mechanism for the clutch release to spring away from the clutch plates. It is in constant contact. Mucking about with springs only regulates the force of that contact.

 

This arrangement *does* make it better to drive because there is no latency in the pedal movement, but the bearing suffers.

[Lennie]

This is common problem. There is only one spring and this pulls the bearing onto the clutch so when it touches it can spring back and then the spring pulls it back on and the oscillations just get worse. A fix is to put another spring [ the same as the one already fitted]on the clutch pedal to oppose the one already fitted and with a little time fidling you can get the pedal at a point where the bearing is not touching and hence stop the pedal jumping. You may have to drill a small hole in the pedal box to have somewere to fix it.

[KenEvans]

Thank you Len - that's very helpful :-)

[ant]

This may explain why Caterham couldn't see anything wrong with mine today. So no extra info. from them, sorry.

 

Ant.

 

ps. Maybe they need Len back.

[John Vine]

Len,

I applied exactly the fix you describe after a catastrophic CRB failure some months ago. But I did it to stop (?) the CRB running in permanent contact with the diaphragm fingers (which is what I believe caused the CRB failure in the first place). It took a while to achieve the right spring rate, but so far, so good....

 

JV