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#351
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What are some car-repair jobs you always wished you could do but have never done?
On Mon, 6 Nov 2017 04:49:14 +0000 (UTC), RS Wood >
wrote: >Steve W. wrote: > >> Chains don't mean a lot when they drop them down to bicycle sizes with >> small pins. Things stretch like cheap rope. > >I think the only reason manufactures went to belts is to increase their >profits, so I wonder if there is any value to a belt AFTER you look at the >tradoffs. No, chains stretch - belts don't. Belt timing is more accurate and consistant. Belts are more efficient at transmitting power. Belts are much easier and cheaper to replace > >The real question for a repair group would be the main factors: >1. Reliability of chain versus belt It can be pretty much a wash >2. Damage potential of chain versus belt When a chain goes bad, it does more damage than a belt >3. Repair hassle of chain versus belt A lot more hassle when a chain brakes. > >Let's ignore the marketing bull**** (e.g., lighter, quieter, etc.) for this >thread to concentrate on the reliability and repair-related issues. > >As I already noted, I *wish* I had replaced a timing chain in my life, but >just like I've never owned a FWD vehicle (and I lived in a "snow state" for >decades), I have never had a belt car and I've never had a chain break on >me. > >So I have no experience. >But.... > >I posit that: >1. The chain is *far* more reliable than the belt Not necessarilly true >2. Both can ruin an interference engine if they break Correct - and the cain causes more damage and is more expensive to repair >3. Repair hassle is probably about the same Nope - an order of magnitude worse with a chain > >The question is how long is the typical MTBF for a belt versus a chain? Belts - 60- 100 thousand Km in the past - some last a lot longer but don't take the chance on an interference engine. an hour or 2 to change it, and mabee 50 bucks for the belt vs 6 hours plus the cost of tensioners and sprockets and chain (often over $200) for the chain - which SHOULD last longer than 2 or 3 belts - but the average car will only have the belt changed 3 times in it's lifetime |
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#352
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What are some car-repair jobs you always wished you could do but have never done?
On Mon, 6 Nov 2017 04:49:16 +0000 (UTC), RS Wood >
wrote: >Xeno wrote: > >>>> I have Toyotas precisely because they have a chain. >>> Some do, some don't. (perhaps today they all do - not sure) >>> >> The ones I buy sure do! ;-) > >Two vehicles that are worthless to me: >1. FWD >2. Belt Absoltely no biggy, on either count. I like FWD. I like RWD. in NORMAL driving, there is basically no difference - and the flat floor of a FWD is nice - and with the weight of the engine over the drive wheels traction is snow is MUCH superior to the traction of a rear wheel drive car with no extra weight in the rear - - - I've had my say on belts |
#353
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What are some car-repair jobs you always wished you could do but have never done?
On Mon, 6 Nov 2017 04:49:21 +0000 (UTC), RS Wood >
wrote: >Frank wrote: > >> Chains are hardly ideal. Chains wear. The wear changes the pitch >> between the links and the links no longer quite fit on the sprockets. It >> turns into a self reinforcing cycle. More wear = worse fit, worse fit = >> accelerated wear. Eventually the poorly fitting chain will jump one or >> more teeth on the crank gear or start breaking the teeth on the cam gear. > >What are our choices? >1. Chain >2. Belt >3. Pushrod > >Anything else? Pushrod can be gear or chain > >> The other effect of chain wear is retarded cam timing. The more worn >> links between the crank and cam, the more the camshaft timing gets >> retarded. I changed timing sets on conventional OHV engines and that >> usually advanced the ignition timing from 5 to 10 degrees, suggesting >> that chain wear had retarded the timing by that amount. > >From a repair standpoint, how long do each typically last? >1. Chain ? >2. Belt ? >3. Pushrod ? Chevy pushrod engines often took out the plastic timing gears in under 100,000 km. Lots of timing chains on pushrod engines never made 100,00 miles. > >I don't hear anyone talking about pushrods, so, all I see here are that >chains last a *lot* longer in general than do belts, where if either one >broke on an interference engine, expensive things can happen. > >> But I still prefer belts. Even on a tight package like a Dodge Neon with >> the 4 speed auto, the replacement isn't too bad, once you know the >> routine. > >If the replacement isn't bad, then the belt isn't 'as' bad. > >In the general sense though, belts, I posit, are bad news multiplied. >I try not to take things from the marketing-bull**** standpoint. The belt is just a maintenance item like plugs > >My take is always from the *why* standpoint. >Why did the automakers go to belts over chains? Because in SO many ways they are better and they are not affected by lubrication issues. > >My supposition is that they did it to save them money. >No other reason. You are wrong > >The tradoffs are legendary where the owner is the one who loses in the end >calculation. > Not necessarily > >>> Just like FWD cars and tricked-out cars are, to me, nearly worthless. >> >> I love front wheel drive, especially in the snow. > >Lots of cars are FWD that never see snow. > >In the general sense though, FWD, I posit, is bad news multiplied. >I try not to take things from the marketing-bull**** standpoint. > >My take is always from the *why* standpoint. >Why did the automakers go to FWD over RWD? For many reasons which I have already given you. > >My supposition is that they did it to save them money. >No other reason. Nope, > >The tradoffs are legendary where the owner is the one who loses in the end >calculation (particularly since deep snow is still on the road for what, >maybe 10 days out of 365?) Not up here. and they make cars for world markets - > >Anyone who mentions snow with FWD is falling directly into marketing hell. >Just like anyone who mentions belts are "quieter" and "lighter" is doing. > >The sole reason for belts and FWD is to increase manufacturer's profits. >Everything else is marketing bull**** because the tradeoffs are legendary. You can believe what you like - but my FWD cars get around in snow al LOT better than my old RWD cars. Try driving a new mustang or camaro in snow. |
#354
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What are some car-repair jobs you always wished you could do but have never done?
On Mon, 6 Nov 2017 04:49:25 +0000 (UTC), RS Wood >
wrote: >Ed Pawlowski wrote: > >> The $50 figure is about 30 years old. If it was accurate at the time is >> would be double that today and there was still a lot of engineering and >> new tooling to pay for. That said, I have no ideal today. > >I remember $1000 but they didn't pass that on to the consumer in toto. > >What irks me the most isn't that they make FWD cars, just like it doesn't >irk me that they make convertibles or muscle cars or economy cars or luxury >cars. > >What irks me about FWD is that the hoi polloi do not UNDERSTAND what FWD >gets them. > >I posit it gets them almost nothing. > >Then the hoi polloi don't understand what they lose. > >I posit they lose handling. > >Maybe FWD is better now ... but I think I'll have to go to my deathbed >before owning a FWD car... simply because I don't want to fall for the >marketing trap that everyone else easily falls into. You are not drinking the coolade, but you are certainly falling for the bull****. |
#355
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What are some car-repair jobs you always wished you could do but have never done?
On Mon, 6 Nov 2017 04:54:55 +0000 (UTC), RS Wood >
wrote: >Xeno wrote: > >>> Hrm.+AKA- I thought that was done to lighten them -- bicyclists are >>> sometimes also called gram-shavers.+AKA- It provides better cooling too? >>> >> Removing mass reduces heat holding ability. The material removed does >> not provide a gain in surface exposure. The real gain is providing a >> path for the gasses coming off the pad surfaces to escape from between >> the pad and rotor. Reduces the hovercraft effect. > >I can spout marketing bull**** as well as anyone can. >I just choose not to. > >If you can find a scientific study that proves for street cars that a >drilled/slotted rotor makes *any* difference over a solid rotor in braking >performance, let me know. > >I'm all about logic. Not for normal legal street driving |
#356
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What are some car-repair jobs you always wished you could do but have never done?
On Mon, 6 Nov 2017 16:25:31 +1100, Xeno >
wrote: >On 6/11/2017 3:48 PM, RS Wood wrote: >> wrote: >> >>> Some of the best rotors out there are Chinese - but also some of the >>> worst. Consistency is the problem >> >> I can't argue but my point is that I've heard everything. >> The problem is that the advice has to be both logical and actionable. >> >> Saying "buy only Brembo or Meyle" is actionable, but not logical. >> Saying "don't buy Chinese crap" is logical but not actionable. >> >> For advice to be useful, it has to be both actionable and logical. >> I've never heard that in rotors other than buy solid and don't buy >> drilled/slotted rotors. >> >> Other than that, there's no way for a person to tell if one rotor is gonna >> be better than another. >> >> Hence pragmatically ... a rotor is a rotor is a rotor is a rotor. >> >>> In some instances (virtually never normal street use) grooved and >>> slotted rotors DO provide better braking. We are talking competition >>> use, where the rotors are glowing red hot half the time, and the pads >>> are off-gassing like crazy - where even 100% dry DOT4 brake fluid >>> boils in the calipers. Under those conditions, rotors can warp - and >>> even fracture (in Rallye use I've seen red hot rotors hit an icy >>> puddle and totally fracture) >> >> I'm never talking racing. >> They drive on bald tires for heaven's sake in racing! >> > >Yep, far better coefficient of friction - in dry conditions. > >> >>> Actually, on SOME cases you can. Look at the consistancy of the fins >>> in the rotors, and the even-ness of the thickness of the braking >>> surfaces on both sides of the fins. >> >> I'm not gonna disagree that we all can see the mark of good quality on some >> things when we have two to compare in our hand, but it's too late if you >> order on the net. >> >>>> How are you gonna know the metallurgy? >>> >>> You don't - that's the hard part - but when you are in the business >>> you get to know which suppliers stand up, and which don't. If you >>> know the suppliers well, they will tell you which ones they have >>> trouble with, and which ones they don't. >> >> Yup. I have nothing against good suppliers. I use Brembo and Meyle but if >> someone else gave me a rotor at a better price, I'd consider them too. >> >>> And some rotors DO WARP. Not many - but I've had at least a bushel >>> basket full of genuinely warped rotors in my 25 year carreer. Most >>> "warped" rotors are not warped - but some are. Some DRASTICALLY - to >>> the point the caliper moves visibly when the wheel is turned - and if >>> the sliders stick the pedal jumps and the steering wheel twitches. >> >> That's not the measure of warp. >> Warp is measured on a flat bench. >> Just like head warp is measured. > >Or with a dial indicator - on both sides - for comparison. >> >>> More often than not though, they are either pitted or have deposit >>> buildup, ot they have "hard spots" due to metalurgical inclusions >> >> The only person who says their rotors warped that I will ever trust is one >> who measured the warp just like you'd measure head warp. > >Use to check for warp every time. >> >> If they haven't measured it, it's not happening. >> And nobody measures it. >> So it didn't happen. > >Some do. I did. I also taught apprentices to measure for it. >> >> It "could" happen. But it doesn't (on street cars). >> The problem is the temperature never gets hot enough. > >It can under specific circumstances. See it most often on autos in very >hilly country. >> >> Now they can be "warped" from the factory; but that's different (and rare). >> >>> Wrong tool. The one I'm talking about has tabs that fit into the >>> notches on the piston face to "thread" it in as you squeese. Can >>> sometimes get away with the $17 "cube" but the kit you KNOW is going >>> to work starts at about $35 for one of questionable quality, and goes >>> up very quickly from there (and IT won't turn back Mazda rear calipers >>> - they use a different system >> >> I think we're talking about two different kinds of disc brake systems. >> I had the Nissan 300Z which had the rear disc also as the rear parking >> brake, but my bimmer has the rear disc and a separate rear parking brake. >> >> The piston arrangement is different as is the way to retract them. >> >> You don't *twist* pistons in disc brakes that I own that don't have the >> parking brake as part of the disc brake itself. >> >> At least I don't. >> >> >>>> Never once in my life have I found a single person who has *measured* the >>>> warp. >>> >>> I have. many times. >> How? >> >>>> You know why? >>>> They don't even know *how* to measure rotor warp. >>>> They don't have the tools to measure rotor warp >>> A somple dial indicator tells the tale >> >> Nope. >> How you gonna tell runut from warp with a dial gauge? > >Measure disc thickness at various points around the disc. If the >thickness doesn't vary, then any runout measured on the dial indicator >is warp. Verified by back and front runout comparisons. > >By the way, thickness variation checks are part of a standard disc >inspection process. > >> >>> - and sometimes one side is >>> straight, and the other side is not - parallelism warpage - where some >>> fins collapse and one side of the rotor "caves in" - 1 inch thick on >>> one "side" of the rotor, and .875 or something like that diametrically >>> across the rotor. - and sometimes virtually deead flat on both >>> surfaces - other times with about hald paralel and the other half >>> "sloped" >> >> Now you're straining credularity. >> >>>> (Hint: It requires a flat benchtop and feeler gauges and it's not hard - >>>> but they don't know that because they didn't measure a single thing.) >>> >>> That won't necessarilly tell you anything. The only way to KNOW is to >>> use a dial indicator properly. >> >> How you gonna tell runut from warp with a dial gauge? > >Compare measurements. >> >>> And that is where YOU are WRONG. >>> Many technicians measure brake rotors virtually every day of their >>> working lives. >> >> On the entire freaking Internet, find *one* picture (just one) of a >> technician actually properly measuring brake rotor *warp*. >> >> Just find a *single* picture please. Just one. >> On the entire freakin' Internet. >> >> Find one. >> >>> Dealerships were then REQUIRED to buy an "on-the-car lathe" to true >>> up rotors. >> >> That's not warp. >> Nothing on this planet is going to fix warp. >> There's not enough metal to remove. > >Depends on the warp severity. >> >>> A wize man learns from the mistakes of others - a fool never learns >>> because he "never makes mistakes" >> >> Which is why I wish I had done these half-dozen jobs: >> 1. Alignment >> 2. Transmission >> 3. Engine >> 4. Tires >> 5. paint > >Done all, taught 1 thru 4 at a technical college. >> >>> Yes - you are right to the extent that MOST "warped rotors" are not. >>> But you are absolutely WRONG when you say they never warp in >>> street/highway use and anyone who says they have had a warped rotor is >>> lying and hasn't measured the rotor to prove it. >> >> I never once said "never" but "almost never" which is different, and we're >> only talking street, and I have references that back up everything I say >> whereas you provided zero references for what you said. >> >> I'm not here to argue opinions. >> I only argue using logic. >> >> Just read the references I provided and then provide some references that >> back up your point of view. >> >> The "Warped" Brake Disc and Other Myths of the Braking System >> <http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths> >> >> The 'Warped Rotor' Myth >> <http://www.10w40.com/features/maintenance/the-warped-rotor-myth> >> >> Warped Brake Rotors - Vibrating Reality or Internet Myth? >> <https://blog.fcpeuro.com/warped-brake-rotors-vibrating-reality-or-internet-myth> >> >> Stop the +IBg-Warped+IBk- Rotors Myth and Service Brakes the Right Way >> <http://www.brakeandfrontend.com/warped-rotors-myth/> >> >> Raybestos Brake Tech School, Part One: Rotors Don't Warp >> <http://www.hendonpub.com/resources/article_archive/results/details?id87> >> Notice amateur Woody is arguing with 2 former professional mechanics and trade school instructors???? I'm done with him. A waste of time, effort and breath. PLONK!! |
#357
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What are some car-repair jobs you always wished you could do but have never done?
On Mon, 6 Nov 2017 17:23:01 +1100, Xeno >
wrote: >On 6/11/2017 3:49 PM, RS Wood wrote: >> Xeno wrote: >> >>>>> I have Toyotas precisely because they have a chain. >>>> Some do, some don't. (perhaps today they all do - not sure) >>>> >>> The ones I buy sure do! ;-) >> >> Two vehicles that are worthless to me: >> 1. FWD >> 2. Belt >> >The past half dozen cars I've had have been FWD. I don't have a problem >with them. My first FWD car was a Morris Mini back in 74 and I have had >heaps of them since. Had heaps of RWD cars too. Totals in the hundreds. 2 mechanics/trade school instrctors who drove Morris Minis ---- |
#358
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What are some car-repair jobs you always wished you could do but have never done?
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#360
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What are some car-repair jobs you always wished you could do buthave never done?
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