yankeedoodoo Posted February 5, 2002 Share Posted February 5, 2002 The one behind the driver. Finally have things roughly put together where it can be driven. The lsd makes an offensive amount of noise @ low speed and gets louder until induction/exhaust sounds overwhelm. The first possibility is amateur assembly by self builder. If this is the problem what sort of things should I be looking for? Could the fluid be wrong and what is most recommended? If the lsd is faulty, how would I know? The car is an slr/zetec/six speed. As always thank you for the assembled wit and wisdom. Link to comment Share on other sites More sharing options...
KenEvans Posted February 5, 2002 Share Posted February 5, 2002 It depends upon the nature of the noise. If it's a general clunking noise as you feather the throttle on and off torque then that's quite normal because of the way in which it's solidly mounted to the chassis and therefore transmits the sound effects (on a de Dion anyway). Anything other than that I can't comment upon. Link to comment Share on other sites More sharing options...
yankeedoodoo Posted February 5, 2002 Author Share Posted February 5, 2002 The noise is directly related to speed, it becomes louder upon acceleration and is more whirring than clunking. Link to comment Share on other sites More sharing options...
KenEvans Posted February 5, 2002 Share Posted February 5, 2002 I beg to differ Yankeedoodoo - I had a word with Len Unwin after I built my Seven and he confirmed that the "clunking" is normal as the play between the gears is taken up. Any road speed related whine is probably due to the LSD being torqued up a bit too tightly - and (though I don't know THAT much about LSDs) I would expect that the clunk and the whine are pretty well mutually exclusive. If the whine isn't too intrusive then it's probably best to let it fade away as the diff beds in - clunking you're stuck with unless the diff is tightened up. It's a bit of a compromise thing really Link to comment Share on other sites More sharing options...
yankeedoodoo Posted February 6, 2002 Author Share Posted February 6, 2002 When driving @ constant speed there is a constant whine, which immediately disappears if I lift off the throttle and go into a coastdown mode. It is also noticeable under acceleration until exhaust/intake/ roadnoise overwhelm. I have not definitively determined that the lsd is the culprit, could it be the 6 speed box? I have "deduced" that it is the lsd because it seems to be related to vehicle speed, probably not engine speed. Note that my deductive reasoning powers are seriously flawed so any help is very greatly appreciated. Link to comment Share on other sites More sharing options...
Peter Carmichael Posted February 6, 2002 Share Posted February 6, 2002 What tyres do you have? ACB10s make a hell of a racket because the tread blocks are cut across the width of the tyre - you get a thump as each tread block makes contact with the ground. Link to comment Share on other sites More sharing options...
yankeedoodoo Posted February 6, 2002 Author Share Posted February 6, 2002 ACB10's. However, I don't beleive it's tire noise as I used to be in that business and can recognize it. Link to comment Share on other sites More sharing options...
MK_Indy Posted February 6, 2002 Share Posted February 6, 2002 The fact that this is a LSD had no consiquence here. The noise will be coming from meshing teeth and there are none inside the slip limiting part of the diff! From what you say, can I assume that the noise occurs while driving the car in a straight line? If so, the torque converter inside the diff will not be taking up any speed differances anyway. It is possible that the half shaft pinions are torqued down to tight inside the unit, they are normally set to minimalise backlash but after a re-build it is east to get carried away when re-fitting them. Can you feel/hear a clunk throught he drive train when you change from under load to coasting? Try a thinner lube too. I ran the LSD on my Cossy on auto box fluid after Ford stopped selling the Duckhams LSD oil and after 40K miles it was still as good as new and as silent as a lamb. Just my thoughts! Paul. Link to comment Share on other sites More sharing options...
Klaus Loske Posted February 6, 2002 Share Posted February 6, 2002 Hi Doodoo... my diff makes exactly the same noise since I put a LSD in. On accerleration, the frequency goes up. If you coast, it makes this nice whirring, singing noise. When you lift the throttle, the singing gets less... I never really worried about it, just really adored the sound of some whirring noise... Have fun Klaus - with the singing 7 Link to comment Share on other sites More sharing options...
sjwb Posted February 7, 2002 Share Posted February 7, 2002 Yankeee, You seem to have a noisy gear set and by that I mean crown wheel and pinion. It may just have been assembled incorrectly, ie the poinion height, but I suspect that it is a noisy set of gears. Just to put the record straight, FDU gears NEVER get quieter - once noisy always noisy and no amount of oil changing will affect it either. If the noise is getting worse, then do have it looked at by a competant person. Steve B Link to comment Share on other sites More sharing options...
yankeedoodoo Posted February 7, 2002 Author Share Posted February 7, 2002 Many thanks to all respondents!! You have given me a good selection of things to check/consider. I'll post the result if I get it under control. To Peter C.: Good luck in your upcoming duel with the obese one. Look out for those Hoosier tires! yankeedoodoo Link to comment Share on other sites More sharing options...
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