Brian Deacon Posted January 20, 2016 Share Posted January 20, 2016 Hi. Zetec engine and five speed box. Recently adjusted idle from high (1200) to more suitable 800 rpm. Now find that I have a loud knocking noise from the rear of the engine or maybe the gearbox. It stops when either the clutch pedal is pressed or the revs are increased. I suspect this is the gearbox, maybe the idler shaft bearings. Any ideas? Link to comment Share on other sites More sharing options...
revilla Posted January 20, 2016 Share Posted January 20, 2016 Quite normal to hear quite a lot of rattly noises from the gearbox at idle as the gears chatter on the shafts at low RPM. As you say, the noise usually goes with a little throttle or when depressing the clutch. I was worried about mine when I first got it but I've since been reassured that what I was hearing was normal. There is so little soundproofing on our cars you hear things that you would never have heard when the box was installed in a Sierra. Link to comment Share on other sites More sharing options...
CharlesElliott Posted January 20, 2016 Share Posted January 20, 2016 Clutch release bearing? Link to comment Share on other sites More sharing options...
Wrightpayne Posted January 20, 2016 Share Posted January 20, 2016 Mine both with 5 speed and 6 speed boxes sounds like a bag of spanners on tickover. Rev or depress clutch and it goes away.TADTS Ian Link to comment Share on other sites More sharing options...
John Vine Posted January 21, 2016 Share Posted January 21, 2016 I'd plump for a rattly gearbox layshaft too, especially if raising the idle speed slightly or dipping the clutch calms things down -- a case of TADTS and nothing to worry about.A failing (or failed) CRB will tend to make noises only when you dip the clutch.JV Link to comment Share on other sites More sharing options...
Area Representative Geoff Brown Posted January 21, 2016 Area Representative Share Posted January 21, 2016 Yup. Rattling lay shaft or idle gear shaft is a common 5 speed box 'noise'. It does not signify that anything is about to fail. It is a "they all do that sir" noise.My 11 year old 1.6K with 5 speeder rattled almost from the moment it went on the road & continued to rattle safely 11 years later & still does in the hands of the second owner some 3 years on. And he changed the release bearing thinking it would cure the noise!To a lesser degree 6 speeders do as well due to the 5 speed lineage.Have you Ford ATF (red) fluid in the box? This oil was recommended by Caterham for the 5 speed box back in the late 90's early 2000's. Due to its limited viscosity it did not control the noise.Change the oil for a 80w 90 or similar & the noise will become less bothersome. Link to comment Share on other sites More sharing options...
Brian Deacon Posted January 21, 2016 Author Share Posted January 21, 2016 Thanks for all the info. Not as worrying now as when I first heard it!Have just checked the gearbox oil level and the oil in there is "redish" so maybe the Ford ATF. I will drain and fill with Comma 80w90 and see what effect it has. Link to comment Share on other sites More sharing options...
Brian Deacon Posted January 21, 2016 Author Share Posted January 21, 2016 Just realized there is no drain plug ! Whats best method to drain? Propshaft off and jack front on car up, or take top of gearbox off and use syringe to suck oil out? Link to comment Share on other sites More sharing options...
SM25T Posted January 21, 2016 Share Posted January 21, 2016 You have to remove the diff to remove the propshaft ! Use a vacuum syringe or pump with pvc tube through the fill hole. You can remove the top cover plate with the gearbox in-situ ..... but it is hard work .... and you'll have a job scraping old bits of gasket off the top flange. I did it this way last time. Top tip from Road & Race .... light smear of silicone sealant on top surface of gasket to keep it attached to the lid ... smear of grease on the lower surface to stop it sticking to the box flange. Link to comment Share on other sites More sharing options...
revilla Posted January 21, 2016 Share Posted January 21, 2016 Some thoughts here: http://www.lotus7.club/forum/techtalk/what-easiest-way-drain-gearbox-oil Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted January 21, 2016 Member Share Posted January 21, 2016 What Ian says, and you'll save a lot of time by warming the oil first.Jonathan Link to comment Share on other sites More sharing options...
revilla Posted January 21, 2016 Share Posted January 21, 2016 Just for info, mine hasn't got the red stuff, it's got 80W90 ... and it still chatters away. I wouldn't go changing the gearbox oil just to fix this. It really is quite normal and harmless. Link to comment Share on other sites More sharing options...
John Vine Posted January 21, 2016 Share Posted January 21, 2016 I agree with Andrew (revilla). Both my 7s (Supersport with 5sp and then 6sp, and R400D with 6sp) have always suffered from layshaft rattle. I learned to live with it.It's worth bearing in mind that, when Henry Ford designed the Type 9 box, he intended the first fill of oil to stay there for life, which is why there's no drain plug.JV Link to comment Share on other sites More sharing options...
Brian Deacon Posted January 21, 2016 Author Share Posted January 21, 2016 Just looked at access to the top cover plate, not easy as you said. Maybe I will try sucking through the fill hole. Bit hit and miss as to where the end of the suction tube ends up but should be able to get most oil out. Job for tomorrow morning, will look forward to it! Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted January 21, 2016 Member Share Posted January 21, 2016 Have you found the trick of cutting a hole from the cockpit through the tunnel side? Some people like that way of improving access to the filler (drainer) hole. (I'm happy without it.)Jonathan Link to comment Share on other sites More sharing options...
SM25T Posted January 21, 2016 Share Posted January 21, 2016 On my 2002 SV the filler/level plug clashes with a diagonal tube in the tunnel side. Link to comment Share on other sites More sharing options...
7 wonders of the world Posted January 21, 2016 Share Posted January 21, 2016 With the oil up to temp pop the filler plug out and feed in a length of 6mm washer tube, pull a vacuum on it with a syringe enough to start a syphon, leave draining into an oil tray for a few hours.Once done refill with 1.2 Ltrs of Redline MTL oil.Measure the oil an fill with a tube and funnel or syringe as Ford have use several filler plugs are various heights over the years depending on application some needing as much as 1.9Ltr which is too much for our application.Have fun Link to comment Share on other sites More sharing options...
Area Representative Geoff Brown Posted January 22, 2016 Area Representative Share Posted January 22, 2016 Machine Mart Suction Gun CGG 500 Code: 040215070 cheap at under £10.Used it on Seven diff as well.....gets the oil out without too much mess. Link to comment Share on other sites More sharing options...
Brian Deacon Posted January 22, 2016 Author Share Posted January 22, 2016 Changed the oil, using tube and syringe, bit messy but not a problem. The fill hole on the gearbox aligns with a chassis tube so unable to cut a hole through.Pouring with rain so unable to see if it has made any difference. Will wait for the sun to come out! Link to comment Share on other sites More sharing options...
Member Jonathan Kay Posted January 22, 2016 Member Share Posted January 22, 2016 Well done.Jonathan Link to comment Share on other sites More sharing options...
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