Mark Durrant Posted July 18, 2003 Share Posted July 18, 2003 John I apologise for not reading your earlier post carefully 😳. Your solution seems to work apart from when driving the car on track or at a sprint when it occasionally emits a grating sound which disappears with a few pumps of the pedal or after stopping the engine, leaving it for a short while and restarting . The engine will probably come out again this winter when I will investigate further. Have you passed your findings and the CRB manufacturers comments on to Caterham's Technical Dept as they need to address this issue. Mark D Su77on Se7ens Avoiding the Kerbs Link to comment Share on other sites More sharing options...
stevefoster Posted July 19, 2003 Share Posted July 19, 2003 It was proper clutch thrust bearing grease I added on Kev's car not your usual stuff... This is strange. Jason B's 1996, K has done 60000 miles on two clutches. I can't remember the reason the first one was changed, worn out or bearing failure. I have a VX clutch plate that has done 25000 miles (not on my 7!) and it's thrust bearing. Both are in good nick. As Kev said you would quite happily put the plate back in for another 25K miles.... I would always change the thrust bearing a any engine out opportunity as a matter of course. They are standard QH. I can did the part number out if needed. Did something change on the K clutch mech recently? Speedy Steve's Workshop here Hants (North) and Berkshire Area club site here Edited by - stevefoster on 19 Jul 2003 08:22:04 Link to comment Share on other sites More sharing options...
masiwn Posted July 19, 2003 Share Posted July 19, 2003 My K series has only done 9000 miles and has very simular symptoms as Philip Smith's car but mine is a 5 speed box is there also a same problem with the 5 speed box? Thanks Aled. Link to comment Share on other sites More sharing options...
KenEvans Posted July 19, 2003 Share Posted July 19, 2003 Just for the record, mine failed in a big way at 6,000 miles on a 1.6K SS with a 5 speed box, just outside the warranty period. Maybe that's why Caterham Cars aren't concerned? Link to comment Share on other sites More sharing options...
John Vine Posted July 19, 2003 Share Posted July 19, 2003 Mark, If you're already experiencing the squealing noise, I fear it may now be too late! It seems that the squeal is caused by the metal bearing housing rotating against the plastic carrier, indicating that the CRB has already suffered overheating and lubricant loss. Re advising Caterham, I wrote to Jez Coates earlier this year, asking about the CRB set-up on my car, and suggesting that the CRB failures had been caused by too low a pre-load. He replied that the Caterham CRB installation "is designed to mimic that of the Ford [sierra]", and that the pedal return spring "will apply a force of approximately 80 Newtons to the release bearing". When I pointed out that (on my car, at least) the pre-load was more like 15N (I supplied my calculations), he replied "I have checked your calculations and agree with your conclusions so I am at a bit of a loss". He recommended I fittted an additional pedal spring (and even sent me one FOC!), but his lack of conviction was a mite worrying! The upshot is that Caterham appear to accept that a pre-load is necessary, and they quote a typical value of about 80N. What isn't clear (yet) is whether they accept that the actual value may be much lower (around 15N), and whether this is likely to cause premature failure. I can see that they might be reluctant to admit this in public, but that doesn't make the problem go away! I'll definitely be sending Jez INA's report on my second CRB failure. More news as it breaks. JV Link to comment Share on other sites More sharing options...
John Vine Posted July 19, 2003 Share Posted July 19, 2003 Aled, The problem occurs on both 5- and 6-speeders. My car is a 1999 1.8 Supersport (5-speed at the time of CRB failures, though now 6-speed). Assuming that your car has the standard Ford Sierra CRB and clutch fork (like mine), the CRB needs to be pre-loaded to 80-120N. I don't know whether the clutch mechanism on dry-sumped cars is the same, so can't comment on that set-up. However, if the CRB is the same part, I would say that the same pre-load is required. JV Link to comment Share on other sites More sharing options...
John Vine Posted July 19, 2003 Share Posted July 19, 2003 Edited by - John Vine on 19 Jul 2003 17:41:22 Edited by - John Vine on 19 Jul 2003 18:09:36 Link to comment Share on other sites More sharing options...
John Vine Posted July 19, 2003 Share Posted July 19, 2003 Ken, I have a sneaking suspicion that you may be right. When I first raised my CRB problems with Caterham, the gist of their reply was that they change very few bearings due to failure. But they didn't explain whether such failures as did arise were outside warranty. JV Link to comment Share on other sites More sharing options...
Mark Durrant Posted July 19, 2003 Share Posted July 19, 2003 John So far the noises do not occur on a regular basis so I'm going to keep my fingers crossed that the bearing holds out until the winter, when I expect to have the engine out for other reasons. Thanks again for your advice and when the bearing comes out I'll send it to Caterham to see what they make of it Cheers Mark D Su77on Se7ens Avoiding the Kerbs Link to comment Share on other sites More sharing options...
John Vine Posted July 20, 2003 Share Posted July 20, 2003 Mark, When you take out the CRB, it might be a good idea to send it to INA (Stewart Davies) first for an expert opinion. Then you'll be forearmed in any subsequent discussion you have with Caterham... JV Link to comment Share on other sites More sharing options...
Mark Durrant Posted July 20, 2003 Share Posted July 20, 2003 John Will do but I am not expecting anything from Caterham. All I want them to do is acknowledge that they have a problem and fix it. The thought of taking the engine out for a second time this year is not appealing Thanks again. Mark D Su77on Se7ens Avoiding the Kerbs Link to comment Share on other sites More sharing options...
JP Posted July 21, 2003 Share Posted July 21, 2003 £300! Is this a DIY job? Link to comment Share on other sites More sharing options...
John Vine Posted July 21, 2003 Share Posted July 21, 2003 All I want them to do is acknowledge that they have a problem and fix it. My sentiments exactly. I wish you luck! Please keep us all posted on developments. JV Link to comment Share on other sites More sharing options...
JP Posted July 21, 2003 Share Posted July 21, 2003 There is apparently un aprated version available for about£70 - is it worth it? Link to comment Share on other sites More sharing options...
Ron_F Posted July 21, 2003 Share Posted July 21, 2003 My apologies if I'm being a bit thick. Doesn't the clutch cable adjustment (at either end) make a difference to the position of the CRB in relation to the clutch, and therefore the pre-load? The adjustment moves the carrier lever inside the bell-housing so surely it must affect the amount of pre-load? Link to comment Share on other sites More sharing options...
Peter T Posted July 21, 2003 Share Posted July 21, 2003 Only the clutch spring has a bearing on the pre load, and anyway once you engage the clutch the bearing is under immense pressure, to whatever pressure plate springs you have. C7 PWT Pure Steel XE. Founder Member of The Twisted Prop Club. Link to comment Share on other sites More sharing options...
John Vine Posted July 22, 2003 Share Posted July 22, 2003 JP, There is apparently un aprated version available for about£70 Do you mean the CRB? If so, that's mighty expensive! Ron_F, The clutch cable itself will apply a pre-load only if it's adjusted to have no slack at all. Assuming a "free" (and frictionless) cable, the pre-load is applied solely by the little spring in the pedal box (which is where we came in, of course, as it's my belief that this spring--as arranged in the standard Caterham design--is incapable of applying the recommended 80-120N load). Peter T, Only the clutch spring... Do you mean the clutch cover diaphragm spring or the pedal spring? Link to comment Share on other sites More sharing options...
Nick Green Posted July 22, 2003 Share Posted July 22, 2003 JP, this 70 quid CRB: What is its preload requirements ? I've talked to Stewart Davies myself. The problem isn't the bearing. It is the preload that is applied to it. John Vine upped the preload by adding springs; I did it more empirically, by shortening the existing spring to up the preload, checking it with a spring balance. The geometry is straight forward. Obviously, only time/miles will tell if we are on the right track, but INA is adamant a specified amount of preload is necessary, which the set up on both John's car and mine did not in any way come close to providing. The mystery to me is how come there are quite a few Ksters out there who have not had this problem at all, depsite lots of miles ? Perhaps their set up just lucked into the right force ? Are they on the forward-most clutch/brake pedal mounting point, which would give the largest preload ? N. Link to comment Share on other sites More sharing options...
JP Posted July 22, 2003 Share Posted July 22, 2003 Chaps, The uprated CRB is just sketchy info I got from Doug at Hyperion yesterday - he may be able to elaborate... Link to comment Share on other sites More sharing options...
John Vine Posted July 22, 2003 Share Posted July 22, 2003 Nick,how come there are quite a few Ksters out there who have not had this problem at allThis puzzles me too (and may account for Caterham's apparent lack of concern). Using the forward pedal mount (that is, the one nearest the front of the car) would certainly help. Perhaps (some of) these lucky people use the clutch pedal as a footrest--not recommended practice, normally--and are inadvertently providing some or all of the missing pre-load! Maybe this whole topic warrants some sort of survey or questionnaire? Is that something our Site Manager could be persuaded to undertake? I'd certainly be very interested in the results. Maybe we'd then have the evidence to persuade Caterham that the problem is real? JV Link to comment Share on other sites More sharing options...
Rob Board Posted July 24, 2003 Share Posted July 24, 2003 John et all, Good to see that the old CRB thread has reared it's big waily nashy teeth again 😬 To back up your woes, I to ponder as to why some CRBs fail v. quickly and some go on and on. Mine which was replaced by CTRM at 2500 miles under warranty has now done another 6000 hard miles and behaved itself impeccably(kiss of death), so I am very happy with their work. However is still a mystery as to why it went in the first place. Or not if our thoughts on the pre load are correct. in that the spring is not man enough? As soon as my clutch gives up, I shall replace the whole affair with a concentric hydraulic clutch, which I feel is the only way to rid myself of any future problems?? I shall read the fiture threads with interest, and good luck with the "fix". Cheers Rob Link to comment Share on other sites More sharing options...
Phil Bishop Posted July 26, 2003 Share Posted July 26, 2003 OK - to take this thread in the opposite direction, going back to the original posting it seems my 1.6 Vauxhall Classic has gearbox rattle - idling at a standstill in neutral, foot off clutch, it rattles away like a good 'un. Goes away when I depress the clutch or add a few revs. Didn't do it at first, but now with 5000 miles on the clock, it's started. Doesn't do it at first either, but only when the engine's hot - perhaps it comes on as the oil warms and thins. Now, does this forbode any future disasters, or is it just an embarrassment? Link to comment Share on other sites More sharing options...
John Vine Posted July 27, 2003 Share Posted July 27, 2003 Phil, I don't think your rattle indicates a CRB problem. Whether it indicates a gearbox problem, though, I wouldn't like to say (but then, it may not be a problem at all). JV Link to comment Share on other sites More sharing options...
timbo Posted July 27, 2003 Share Posted July 27, 2003 what's your idle like - if its flucuating - that will contribute to the gear shafts chattering as the springs in the clutch soak up & release the crank motion causing the gear shafts to rotate at constantly variable speeds. When you engage the clutch or slightly rev the engine the noise goes away as the shaft takes up constant acceleration. I found this out when I switched back from M3DK to std EU3 Mems - as soon as I went back to the mems the gearbox chatter nearly totally dissappeared. The idle variation does not have to be audibly obvious in terms of flucuation to cause this. It's only a suggestion - but try raising the idle screw slightly - see if the chatter reduces. What is your current idle? Are the carbs balanced again? Not f**king fame academy on again Link to comment Share on other sites More sharing options...
Phil Bishop Posted July 27, 2003 Share Posted July 27, 2003 As the engine warms, of course the tick over speed tends to drop lower. A touch on the throttle stops the rattle, but perhaps I will adjust the screw as well. Carbs are well balanced - just been serviced professionally for the first time at the 7 Workshop in Hoddesdon in advance of a trip to Ireland tomorrow. Generally running like a dream. Naturally, though, with a trip abroad coming up I'm fretting about any unexplained noise! Link to comment Share on other sites More sharing options...
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