Mucus72 Posted September 26, 2016 Share Posted September 26, 2016 I have a few queries after my first 2 weekends of driving, and now with about 300 incorrectly recorded miles on the clock!1. Calibrating the speedo. I was heading the blat chain down the M1 in a 50 zone and I had complaints from the others later that I was only doing 40! How do I recalibrate the dial please?2. Brake fluid leak. Basically the o-ring under the screw cap for the reservoir is about 1mm thick. After checking another 1 year older car with the same spec at the motor museum yesterday, his is at least 5mm thick and properly seals the unit. Quite simply the thinner ring will never allow you to screw down the cap tight enough. We checked another new build that has only driven one blat and it was leaking too. Mine leaked enough to strip paint on the side skin edge under the bonnet. Does anyone know the spec or part number of the thicker one please?3. Duratec plus Mazda (quite wide, touches the chassis sides) gearbox vibrates the chassis quite a lot. After an hours drive my hands are fizzy and I can't feel them properly. My old K wasn't like this. Is this normal?4. Maybe related to 3. The vibrations are enough that in this inaccurate 300 miles of driving both screws (which were tight) for the cam cover have undone themselves, disappeared and the cover was just floating on top of the engine. Now I know I can get more screws and use thread lock, but does this sound normal?I'd appreciate thoughts and help as usual please!marcus Link to comment Share on other sites More sharing options...
Jonathan Kay Posted September 26, 2016 Share Posted September 26, 2016 Calibrating the speedo. I was heading the blat chain down the M1 in a 50 zone and I had complaints from the others later that I was only doing 40! How do I recalibrate the dial please?But it reads consistently... no variation at constant speed?Two parts to this:Getting the correction rightI'd check the observed reading against the values from a GPS device* at the speeds of interest to get a correction factor.Changing the settingIs it like the type described here? John Vine published a list of factors but the links are broken. I'd use a correction factor from your current value but you could also start with an absolute value like those.Jonathan* Not against fellow-travellers! Link to comment Share on other sites More sharing options...
SM25T Posted September 26, 2016 Share Posted September 26, 2016 If the engine is touching the chassis ..... that's not right !!! Link to comment Share on other sites More sharing options...
Jonathan Kay Posted September 26, 2016 Share Posted September 26, 2016 If the engine is touching the chassis ..... that's not right !!!I was going to suggest going over all the engine and gearbox mounts, but this is more important. Where does it touch?Jonathan Link to comment Share on other sites More sharing options...
Mucus72 Posted September 26, 2016 Author Share Posted September 26, 2016 Hi Ian,what I meant is that the new(ish) Mazda 5 speed is a wide unit and although I centralised in the chassis when I fitted it, it was touching the silver heat reflective padded material on both sides of the transmission tunnel. I'm guessing that this may be the reason why I feel so much vibration. But not sure if it's all simply TADTS Link to comment Share on other sites More sharing options...
Mucus72 Posted September 26, 2016 Author Share Posted September 26, 2016 Hi Ian,what I meant is that the new(ish) Mazda 5 speed is a wide unit and although I centralised in the chassis when I fitted it, it was touching the silver heat reflective padded material on both sides of the transmission tunnel. I'm guessing that this may be the reason why I feel so much vibration. But not sure if it's all simply TADTS Link to comment Share on other sites More sharing options...
Mucus72 Posted September 26, 2016 Author Share Posted September 26, 2016 Hi Jonathan,speedo needle is stable, I just think it over reads. But it's a simple test I didn't think to carry out with a GPS at a few constant speeds. Will do that next time I'm out. Thank you! Link to comment Share on other sites More sharing options...
ChrisC Posted September 26, 2016 Share Posted September 26, 2016 Now your car have passed the IVA switch to the race brake fluid cap, it has no holes and therefore can't leak even if inverted.I found the caps can also leak if they have been over tightened once to many times (same as the coolant cap)It means you wont have the brake fluid level warning light, but that's a small price to pay. Link to comment Share on other sites More sharing options...
Ian Mackenzie Posted September 26, 2016 Share Posted September 26, 2016 Hi MarcusNice to meet you at Gaydon yesterday.Here is another race cap with the warning switch, but not sure if it will fit you reservoir: http://www.caterhamparts.co.uk/product.php?id_product=1714 With the new speedometers, I think if you press and hold the trip reset long enough it should bring up the option to calibrate, get the true versus indicated speed ratio and adjust accordingly....CheersIan Link to comment Share on other sites More sharing options...
MADMALC Posted September 26, 2016 Share Posted September 26, 2016 Over filling the brake master reservoir makes leakage more likely during spirited driving. Take some fluid out so the level is well below the top of the filler and it will help.On the vibration issue it is worth checking that the steering column is not touching or nearly touching any part of the engine. Things can be a little tight around the UJ at the lower end of the shaft. The rack can be loosened and rotated to adjust the route the shaft takes. Link to comment Share on other sites More sharing options...
Jim 123 Posted September 26, 2016 Share Posted September 26, 2016 Marcus from my experience the latest Mazda 5 speed does contact the heat shielding along the inside of the transmission tunnel, but this may not be the source of your "vibrations". I'd suggest you check the chassis longitudinals that run along the bottom of the transmission tunnel and see if there is a constant gap between the gearbox casing sides and the top edges of the longitudinals. If the clearance at any point is only a couple of m.m. you might be getting a touch condition when on the road. Link to comment Share on other sites More sharing options...
ChrisC Posted September 26, 2016 Share Posted September 26, 2016 Not at Gaydon, spending all the time I can find building, but not getting very far :-( This is the cap I used, no leaks after fitting this bad boy.http://www.caterhamparts.co.uk/product.php?id_product=914 Link to comment Share on other sites More sharing options...
revilla Posted September 26, 2016 Share Posted September 26, 2016 Just to add to Marcus' description of the vibration issue ...I've been for a ride in his car. Right from the moment you start the engine, even sitting still at idle, the whole frame sort of buzzes and zings in a way that is completely different to my K Series VVC. In my car you can hear the engine but you don't feel it when stationary; in Marcus' car you are very much aware of the mechanical goings on under the bonnet, you feel it through your bum, it your knees touch the sidewalls (I'm a tight fit in Tillets!) you sense the tingling and buzzing, your hands feel it. So it's not so much an issue of something contacting under load, it's a vibration that is there all the time and just builds as you accelerate.The engine still feels very healthy though - and it goes like stink! Link to comment Share on other sites More sharing options...
Sim Posted September 26, 2016 Share Posted September 26, 2016 How's the Mazda box mounted? - It's definitely isolated from the chassis? Link to comment Share on other sites More sharing options...
Mucus72 Posted September 26, 2016 Author Share Posted September 26, 2016 Yep it sits on a rubber cradle (big chunky C shape) bolted to the chassis. Link to comment Share on other sites More sharing options...
nickh7 Posted September 26, 2016 Share Posted September 26, 2016 I think you need to get that 7 up on a ramp and look underneath something is touching somewhere all the time and needs sorting and soon . I'd start at the gearbox mount Link to comment Share on other sites More sharing options...
Jonathan Kay Posted September 26, 2016 Share Posted September 26, 2016 Good point about the steering column. Wiggle all the exhaust joints and brackets? Loosen them one at a time and see if it affects the vibration?Ditto engine and gearbox mounts?Take up thy stethoscope?Jonathan Link to comment Share on other sites More sharing options...
ScottR400D Posted September 26, 2016 Share Posted September 26, 2016 My brake and clutch M/Cs leaked on first track outing. Changed the cheap clutch cap for a Girling and cleaned and retightened brake cap. They don't seem to leak now but I cable tie some blue paper wipe around just in case! As for the vibration, I can't see why the gearbox touching the chassis, or anything touching for that matter, would cause screws to vibrate loose, if the two events are connected. What is the source of the vibration would be my question. I've never noticed any similar, significant vibration from my R400, nor any loose screws in 3500 miles. Link to comment Share on other sites More sharing options...
nickh7 Posted September 26, 2016 Share Posted September 26, 2016 just had another thought , I had an engine mount fail and the first clue was the vibration from the engine being supported on the alternator . Could it be a duff engine mount ? Link to comment Share on other sites More sharing options...
SM25T Posted September 26, 2016 Share Posted September 26, 2016 Hope it isn't something way off balance (unscrewed) inside the engine ?? Link to comment Share on other sites More sharing options...
wjblundell Posted September 26, 2016 Share Posted September 26, 2016 Fit the master cylinder race cap with the rubber bellows, it solved the problem completely on my car. Don't forget to refit the original for future MOT's. Link to comment Share on other sites More sharing options...
Mucus72 Posted September 26, 2016 Author Share Posted September 26, 2016 Looks like I'll be getting one of those race caps with bellows, makes sense. As for the vibrations, thanks for the guidance guys. I will get it up on axle stands and have a play this weekend. It is quite serious vibrations. Maybe there is something wrong with one of the engine mounts, as to unscrew the cam cover in a few hundred miles and to shake me almost senseless must be something like that. Might need your support Andrew R if you have any time? Link to comment Share on other sites More sharing options...
revilla Posted September 26, 2016 Share Posted September 26, 2016 I will be tied up with kids stuff on Saturday but I may have some time on Sunday. Better check plans with the social secretary. I don't mind offering support but I think you will find the axle stands work better! Link to comment Share on other sites More sharing options...
JNC Posted September 26, 2016 Share Posted September 26, 2016 This may be a silly question from someone who drives and not built !, are the engine mounts straight or angled, if they are angled and fitted the wrong way round is the engine set back further than should be ?. Link to comment Share on other sites More sharing options...
ScottR400D Posted September 26, 2016 Share Posted September 26, 2016 You couldn't really do that JNC, all sorts of things wouldn't line up, gearbox mount, exhaust, inlet..........and I'm sure it would be picked up at the PBC. Well I would hope so! Link to comment Share on other sites More sharing options...
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