Area Representative Steve Wright Posted August 23, 2012 Area Representative Share Posted August 23, 2012 I know that there has been some discussion about this and I have done a search on TechTalk but can't seem to find a definitive answer. One of our Norfolk owners has bad clunking from the back end, on drive and overrun. Rotating the drive shafts manually from underneath the car reproduces the noise. The car is a recent new build by Caterham. It is a Classic so I suspect that it does not have an LSD. The car has been back to Caterham a few times for this. They state that the setup is performing normally. The owner is obviously unhappy with this and is looking for a fix. So, the bottom line is: Is there a fix for this or is it a case of "They All Do That" Thanks Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted August 23, 2012 Share Posted August 23, 2012 BMW diff or Ford ? - oops re-read the heading ! CC has the responsibility - with a diff like the BMW, replacing the whole unit is probably easier that the adjustments on the old Ford style ? Edited by - Stationary M25 Traveller on 23 Aug 2012 18:48:07 Link to comment Share on other sites More sharing options...
Titanium7 Posted August 23, 2012 Share Posted August 23, 2012 Steve I have one with a Tition LSD and is has a small amount of 'slack' in the mechanism which gives out a few minor clonks but not in the same league as the previous Ford diff which was virtually deafening with the persistant whine and huge amounts of backlash causing chatter on the overun and major clonks. To me the noise from the BMW diff on mine is acceptable bearing in mind the way its mounted. Link to comment Share on other sites More sharing options...
The Pikey Posted August 23, 2012 Share Posted August 23, 2012 Quoting Steve Wright: Rotating the drive shafts manually from underneath the car reproduces the noise. Are you saying with both wheels off the ground and when you turn one wheel it clunks? If so then something is defiantly wrong. Jason Link to comment Share on other sites More sharing options...
1360rallye Posted August 23, 2012 Share Posted August 23, 2012 When I took my car for it's 1000 mile check to Millwood I asked them to check the level of clonk in the BMW diff (LSD). They reported that it was too noisy and recommended that it be replaced. I contacted CC who said TADT sir and that a replacement would make no difference ( they speculated that Millwood weren't familiar with the BMW diff) but that if I wanted to swap it I could. So I took out the diff and drove to Dartford to swap it. Fitted the new diff and it did at first seem less clunky. However within 50 miles it seemed pretty much the same as before. So I'm now somewhat perplexed. It's more irritating than noisy. I'm hoping to compare the noise of the diff with others at next Saturdays Llandow track day. When i took the original diff out the oil was black - does that indicate a problem after just 1000 miles? Andrew Link to comment Share on other sites More sharing options...
Rob Walker Posted August 24, 2012 Share Posted August 24, 2012 Does not sound right Andrew and I would not expect the diff oil to go black ever. Sounds like its getter very hot. Rob Edited by - Rob Walker on 24 Aug 2012 09:47:50 Link to comment Share on other sites More sharing options...
charlie_pank Posted August 24, 2012 Share Posted August 24, 2012 Perhaps the black is from the friction plate material? Link to comment Share on other sites More sharing options...
Area Representative Steve Wright Posted August 28, 2012 Author Area Representative Share Posted August 28, 2012 Update: The fault can be reproduced with the car jacked up and the wheels off the ground. I got it wrong in the original post, rotating the propshaft (not one of the drive shafts) induces the clunk and play can be seen in the UJ. Car has gone back to Caterham again, I hope to update this thread with good news in due course. Link to comment Share on other sites More sharing options...
Guest Posted May 22, 2014 Share Posted May 22, 2014 Hi, I have a 2012 academy with the same issue. The car is now sitting in Datrford having the rear diff carrier replaced to the uprated one, did you managed to get it sorted in the end, when I reported the noise I got the same TADT answer. CC are repalcing all carriers to the new version on any cars that are serviced or have any work done, I am however dubious the carrier is the reason for the clunk. Thanks Link to comment Share on other sites More sharing options...
Guest Posted May 25, 2014 Share Posted May 25, 2014 I have a newly built roadsport with a non LSD and I have an occasional clunk from what sounds like the diff and a whirr/whine from sounds like the gearbox in 4th on overun. I have put it down to the nature of the car and the concept that it is not supposed to be a highly refined ride. Maybe I should be concerned. I am going to check fluid level now I have done a few hundred miles. Link to comment Share on other sites More sharing options...
Guest Posted May 25, 2014 Share Posted May 25, 2014 Car back carrier replaced for the new updated version the old one was broken and that was indeed causing the noise a small clunk is expected with the play on the drive shaft but mine felt like something was broken which it was if you look under the car check u have the latest carrier with the countersunk screws and that the bolts are tight. Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted May 27, 2014 Share Posted May 27, 2014 One thing I had to be careful of after installing the upgraded diff cover and carrier, is that on my R400 the new cover is about 10mm closer to the boot floor than the original cover. The fuel pipe after emerging from the tunnel at the front of the diff has to pass over the top of the cover to avoid introducing tight bends into it, but the clearance to the boot floor is too little with the new cover. I decided to put a 'U' shaped notch in the top of the cover above the full width bolt hole to avoid trapping the fuel pipe, but re-routing may be a viable solution, too. Link to comment Share on other sites More sharing options...
Rattie Posted May 28, 2014 Share Posted May 28, 2014 I suspect people may be barking up the wrong tree there. These tripod type UJs are wide tolerance items. They clonk annoyingly, independent of the diff, which I've found to be great since the swap to BMW. If Steve or anyone else find any low slop replacement for the standard tripod UJs I'd love to hear about it. Link to comment Share on other sites More sharing options...
evotell Posted May 28, 2014 Share Posted May 28, 2014 I had an interesting conversation yesterday with Phil at Road & Race Transmissions. As many people know Phil has had a load of experience with the Caterham diff. I explained the issue we have with clonking in BMW dif. Phil indicated that on several occasions they have found that its the drive shaft not resentering itself due to the spring in the CV being dislodged, this then has all sorts of ramifications including a clonk on lift off. I checked both DS and sure enough the left hand side shaft hardly moves compared with the right side. Next project is to remove the rubber gaiter and see what's going on. Phil indicated that on several occasions once this problem was rectified the clonking went away. Fingers crossed. Link to comment Share on other sites More sharing options...
Rattie Posted May 28, 2014 Share Posted May 28, 2014 Interesting. I didn't notice the drive shafts originally having spring centering in them, which you would feel as the axle carrier needing preload to mount up on the deDion ears, but maybe at full droop you just don't notice this. not sure where a spring would dislodge to, maybe they're using tripod joints without springs. Anybody got a recent driveshaft off the car, or experience with one that has noticed preload? Link to comment Share on other sites More sharing options...
evotell Posted May 28, 2014 Share Posted May 28, 2014 I will report back with what I find Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted May 29, 2014 Share Posted May 29, 2014 Quoting Rattie: Interesting. I didn't notice the drive shafts originally having spring centering in them, which you would feel as the axle carrier needing preload to mount up on the deDion ears, but maybe at full droop you just don't notice this. not sure where a spring would dislodge to, maybe they're using tripod joints without springs. Anybody got a recent driveshaft off the car, or experience with one that has noticed preload?Yes, I found preload that I recall to be about 5kg, with a shaft movement of up to about 15mm away from the diff being possible. I was surprised that this preload is all that keeps the diff end of the shaft in place against the oil seal and bearing. One thing to be careful about with the BMW diff is that the side bearings are held in place with large circlips that have a specific thickness that is adjusted on each side to give the correct bearing load and lateral ring and pinion mesh, if they are removed to gain access to the LSD, they have to go back on the correct side (the thickness in mm is etched on the circlip face). Link to comment Share on other sites More sharing options...
SBD762 Posted May 29, 2014 Share Posted May 29, 2014 I am ashamed to say, I have no idea what diff I have. Car is a 2007 K series 1.6 Roadsport. However in the two years I've owned it, the "clonking" had been in existence on overrun and acceleration. And it's noisy! I too have put it down to the nature of the car. Bloody annoying! But part if the experience of a Caterham. On occasions I can quieten it down by very controlled, precisely timed and managed gear changes with very careful (smooth) acceleration ....... But why would I want to do that all the time, I just drive it progressively and let the noise carry on annoying me! Apology for not being much help to the original post, but I am guessing this is a characteristic of the Caterham 7? Link to comment Share on other sites More sharing options...
evotell Posted May 29, 2014 Share Posted May 29, 2014 Quoting SBD762: I am ashamed to say, I have no idea what diff I have. Car is a 2007 K series 1.6 Roadsport. However in the two years I've owned it, the "clonking" had been in existence on overrun and acceleration. And it's noisy! I too have put it down to the nature of the car. Bloody annoying! But part if the experience of a Caterham. On occasions I can quieten it down by very controlled, precisely timed and managed gear changes with very careful (smooth) acceleration ....... But why would I want to do that all the time, I just drive it progressively and let the noise carry on annoying me! Apology for not being much help to the original post, but I am guessing this is a characteristic of the Caterham 7? I would like to suggest that your problem is common but NOT normal. As a Used Caterham Dealer we have had many Caterhams go through our hands and the majority have completely silent diffs, NO NOISE AT ALL. I suggest you take it out and get it to Phil at Road & Race transmissions and get Phil to sort it. Link to comment Share on other sites More sharing options...
Rattie Posted May 30, 2014 Share Posted May 30, 2014 @SBD, How much UJ shunt do you have? To work this out, the easiest thing to do is to jack up the rear and rotate each of the rear wheels to see how many degrees it'll turn without rotating the inboard UJ casing on that side. It may help to select 1st to provide some resistance, depending upon diff type. I'd be interested to know what kinds of angles people get. Mine is a bit slack and can even help cause kangarooing at low speeds and small throttle openings. It does concentrate the mind on smoothness, even to the extent of declutching when transitioning from power to overrun. Link to comment Share on other sites More sharing options...
Guest Posted June 1, 2014 Share Posted June 1, 2014 I've been clocking up the miles since getting mine on the road and I do find it odd that there is such a noise on overun, especially in 4th. I checked my oil levels in the diff and gearbox and everything is fine. It is a BMW Non LSD. I have redline MTL in the 5 speed type 9 and Millers Classic Differentail Oil 90 API GL5 Hypoid. If this is normal and better than the old sierra boxes I would hate to hear the noise they make. Is it a case of getting it set up properly or I have got it wrong with the oil selection? Andrew Link to comment Share on other sites More sharing options...
Damo V Posted July 7, 2014 Share Posted July 7, 2014 :newbie: Hi people. Sorry to hijack this I have a. 2013 supersport R duratec. Will this have a BMW diff? I get the clonking which I had out down to LSD but even worse is the horrendous growl on over-run in third or fourth. Strangely with a passenger the noise is nmore prominent. It has been back to Caterham as they are 5 mins from me and they claim to have tried another diff and prop I was told it didn't make any difference. I was told not to worry about it but as a first time owner I didn't want to come across as a moaner! It is less than 12 months old and has done 1800 miles. Would the revised diff carrier apply to this year? Link to comment Share on other sites More sharing options...
Stationary M25 Traveller Posted July 7, 2014 Share Posted July 7, 2014 Hi Damo V You can't be far away You'll have to join us one Sunday morning Link to comment Share on other sites More sharing options...
Alan Reeves Posted July 7, 2014 Share Posted July 7, 2014 Damon you have a BMW diff and I'm sure it should have the revised carrier When I had mine without LSD it was fine, Link to comment Share on other sites More sharing options...
Rattie Posted July 8, 2014 Share Posted July 8, 2014 Hmm, could be gearbox. Particularly if it's in just some gears and not others. Not a given, because it could be a product of speeds and loadings that you only get in those gears, but I'd have my suspicions. Our 6 speed box is now more noisy than the diff since our swap to BMW. edit to add: Noises get transmitted along the propshaft/tunnel and can appear to be coming from the opposite end to where they originate. Edited by - Rattie on 8 Jul 2014 16:38:11 Link to comment Share on other sites More sharing options...
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