that's the radial internal clearance expect dave will chip in on this but low clearance is for things like machine tools that you don't want a lot of movement a bigger clearance is for things that run at higher temperatures or as you said low friction thing you get something like 5 groups of clearance
My wife works for a high-tech German company in Ireland. The horror stories she tells me about the rubbish they produce is scary. The latest is that steel shavings, believed to be from inside the production machines, were found in the products, and thus thousands were scrapped. As she said: "How many got through where the steel was not spotted?" The problem in that company is that none of the personnel have the technical education, or ethos, to produce technical products. Upper management are all unqualified in any subject at all, let alone a technical discipline. Even worse, hence the present problems, none the so called 'Maintenance Technicians' are qualified either. The German bosses have threatened to close the factory on more than one occasion, because of similar problems, and if they found out about the latest fiasco I believe that they would now do so. Mind you, it serves them right for promoting the store keeper to General Manager. So. Even if, like SKF, a world leader in a particular product sets up a production facility and establishes a quality control system of the very highest standards in a country without a historical technical background the chances are that the locals won't have the necessary ethos.
So, it's 'just a thought' and thus your opinion is purely subjective! Objectively testing them back-to-back under controlled conditions is the only way one can make real value judgement! Mind you. I doubt that these days even the major manufacturers test things properly? At Laycocks every overdrive was fully tested at the end of the assembly line in a test booth. These were awful places to work, full of oil and noise. We had a half dozen cars which were out in Derbyshire all day every day properly road testing overdrives and clutches. And. We had two dynamometer test rigs powered by Rolls-Royce V8s. (R-Rs because of reliability). Overdrives were put on these and literally blasted with more power and torque than any of the cars they were destined for could ever produce: Fords, Volvos, Triumphs, Vauxhalls, Ferraris, Maseratis, etc
Of course: FAG also have manufacturing facilities all over the world, and so may also make wheel bearings in countries without any 'Engineering Ethos'. And: LUK is part of the same group as FAG. As we all know, from a purely Engineering Design perspective, LUK are not as good as SACHS. So: Will FAG wheel bearings be German? This is interesting!
Ah right, so before buying any parts I should test available options under controlled conditions to see which is best. Ok then. SKF bearings work. Buy them, fit them, sleep well at night. I admire your approach to engineering and quest for perfection but to me it seems like you often look for issues where there are none and it borders on unnecessary scaremongering.
Not at all. What I pointed out was that making value statements is meaningless without accurate data to support such claims. I never said that they did not work! I said that in my opinion there's 'Now't wrong' with them. Thank you. But: I do not seek perfection as perfection is impossible! I have always sought elegant Engineering solutions within limits imposed.But I do always explore the possibilities towards the 'right' Engineering solution. As to issues: If by that you are referring to my preference for Swedish made bearings, or German made ones, than those manufactured in Brazil, then it is an issue for me. From my experience I know how very high Swedish and German Engineering standards are and I would rather rely on what I know. Again from experience, having worked with many vehicle manufacturers, I know that Saab's Engineering and Quality requirements are higher than those of Mercedes, Volvo, and every other one we supplied. Having worked with SKF in Sweden I know that they are in the same league as Saab. The reason that companies make products in such countries as those mentioned is that it is cheaper to do so and thus supply the local users at a price that they are willing to pay. But when these companies sell the same products in Europe they charge as much as they can get away with that we are willing to pay. As to scaremongering: The only scaremongering in this thread is in regard to issues with FAG. All I have done is express my own doubts. I have nowhere advocated not to buy SKF. You yourself have doubts regarding the bearings that you have fitted as you change them up to twice a year. It would probably be cheaper to buy monitoring equipment to assess bearing condition than change them so often. Then you could furnish us with accurate objective data so that we can all make a value judgement.
Good day folks, Thought I would give this thread an update. The machine shop has finally finished boring out my wheel bearing housings. They had to make a fixture to secure the housing to so that it could be mounted on a lathe. A couple of pictures The fixture was manufactured toa .0001" tolerance for parallel. The housing bolts to the fixture via the three holes used to secure to splash sheild. Then the assembly is mounted to the lathe and indicated. The machinist needed four cuts on the first one to allow him to sneak up to the final dimension. When they were all set up and ready to run they invited me down to observe the actual process. Amazing how easy a competent machinist can make this look. He assured me there was a fair amount of thought that went into this. Originally the thought was to mount the housings on a mill but the machinist felt that by making a jig he would have better repeatability. I don't know. I know just enough about machining to really know that I don't know squat. Just as another FYI. I was able to purchase 5 official VAG wheel bearing kits. The bearings that came in the boxes were SKF, made in Spain. I figure if it's good enough for VAG then they should be ok Fingers crossed that my next update will be that I actually finished a race without breaking something. Wish me luck....... Regards Craig
UPDATE: Good News! While it wasn't an event that I normally do I took the car to a track day Sunday at my local track. I got to run the car hard for about 2 hours spread out over multiple 20 minute sessions and the car performed flawlessly. There were no noises, vibrations or any other driveline anomalies. It isn't nearly as punishing as a typical endurance event is but I'll take it. I'm going to run the car at one more track day type of event and if she passes that test we will prep her for an 18 hour race in September at Summit Point West Virginia. Thanks again Craig
Thank you for sharing the outcome of your development Looking forward to a report on one of you endurance events And maybe even a thread in the Members Gallery of your mk1 It looks very interesting
