The 5 Second VW belt change

What is it about old boxer engines that thrills me so?

(Thanks, Peter!)


  1. This is also a convenient and quick way to remove your fingertips, especially when you’re doing it barehanded(!!).

    1. This was my first thought too: looks like an efficient way to separate your fingers from the rest of your body.

      1.  Do not make the mistake of using your blasting rod instead of a screwdriver, however. That’s a good way to lose more than a few fingers.

        1. This exchange took place and I registered it as normal, understandable English before I realized what it was referencing. 

          Who uses a focus as outdated as a blasting rod anyway? 

    2. Barehanded is how you’re supposed to use sanders, grinders, and similar high-speed tools where your hands get anywhere near the business end. You might get some skin shaved off or worse, but it’s still a lot safer than getting a glove caught up in the works with your hand still in it.

  2. That violates everything I ever learned about maintaining a VW. 

    Most significantly, when the alternator isn’t spinning, neither is the cooling fan. Lose the belt while driving on the road, most of the time the engine will cook itself to death before the driver realizes something is wrong. 

    Secondly, the larger wheel is connected directly to the crankshaft and is spinning with the full force of the engine behind it. Even a 50 horsepower engine will shred anything soft and fleshy that gets caught up in it without breaking a sweat. 

    1. The engine isn’t going to overheat in 5 seconds at idle.  The danger of messing with a spinning pulley is very real though.  It would be so easy for the screwdriver to get pulled along by the belt a little too much and go flying around the pulley. 

      1. Not necessarily. 

        “What Happens in Bartertown, Stays in Bartertown.”

        Anyway — I know you’re kidding, but people often do procedures like this while moving very, very fast. Ideally, the procedure is SOP and part of the job — these peeps don’t have (noteworthy) accidents ’cause they’re well trained and know what they’re doing…fcuk-ups might kill people, or at least them or their careers. 

        The cautionary tales are spawned by, well, you know…

  3. A doctor friend of mine came home from an ER shift with a story about guy who came in with a Crescent wrench sticking out of his cheek. He had dropped it into a running engine, and it had been spit out handle first. The handle entered his cheek just below his eye and penetrated to behind the eye, cutting the optic nerve.

  4. Maybe it’s the fact that they are extremely well balanced, easy to maintain, and generally easier to keep going longer?

    1. Agreed.

      Aircooled bugs used a shim design in the alternator/generator pulley to proper tension the belt (expanding the pulley apart to reduce tension).  Aftermarket belt tensioners could be installed, but that’s not the case here.  I’m sure in a pinch this would work, but so do a lot of other questionable automotive procedures.

      1. Exactly.  You might be able to change a VW belt in 5 seconds without losing any fingers or having a screwdriver flung through your face, but just try tensioning it correctly in a non-stupid amount of time.

        Especially if the previous adjustment tightened a worn belt by removing some of the shims (fairly typical), and the car’s owner has no idea where the spare shims went.  

        Especially if it’s 2 am and you’re trying to get home from the beach.  Guess how I know this. :-)

        For a supposedly “simple to maintain” design, the VW’s stock belt-tensioning method is laughably bad, and stupidly difficult to maintain.  

        And of course it makes risking mayhem to save the two minutes that removing and replacing the belt safely would otherwise take kinda pointless. 

        On my old late-70s (pre-Nissan) Datsun, this trick might have made some sense, since I could easily adjust the belt tension with the engine running – if I were the sort of shade-tree mechanic who thought this was a cool trick.  (Though the odds of spitting the screwdriver out through the radiator would add an additional level of thrill that the VW admittedly lacks.)

        1. As a former mechanic (who has seen practically every take on tensioning belts) and a former classic beetle owner I have to disagree with your supposition that the stock belt-tensioning method is “laughably bad”. It’s simple, it works and it’s easy to maintain. It doesn’t require an idler pulley / tensioner arm assembly that costs 200 dollars. If you have 1/2 inch of play when squeezing the belt on both sides at the same time you are good to go. A rare earth magnet from the hardware store will let you keep shims safely in the engine compartment, or alternatively in the glove compartment. I think what people miss when dealing with these cars is the era they were designed in, during that time if you owned a car you knew how to adjust the valves, change the oil and belts, and maintain the battery. Today the automobile is designed and used as a black box mores the pity.

          1. Agree. Plus, if I’m remembering right, you just store extra shims you’re not using under the domed washer on the outboard end of the shaft, so they’re always right there when you need some. Brilliantly simple, like most systems on these engines.

      2. It gets worse when you start working on the wasserboxer: the waterpump belt is the alternator belt. When I saw the Battery light come on a few weeks ago I thought, hell the fan may be stopped but the water is still circulating. I can get to my mechanics shop. I now am replacing the motor and much of the cooling system. 

        Now my BMW R75/6? That engine is simplicity in itself.

        1. My next bike likely will be a BMW, if not the next, it’s a goal. I haven’t owned a motorcycle for years, the ones I had were Japanese — great f’ing bikes. 

          Anyway, I was at a get-together and mentioned this to a friend who is a old-school BMW bike enthusiast. He pretty much said what you said, plus a lot of other technical stuff that convinced me. Simplicity…fcukn’A…

    1. Nah.  Dangerous, sure, but not incredibly so.  Driving a VW bus on the freeway these days?  Incredibly dangerous.

  5. Cool trick.  Reminds me of how, when I was a kid, I learned to put my bike chain back on *while riding and not stopping* if the derailleur had accidentally removed it entirely from the sprocket.  (This was in the days before modern derailleurs could be programmed with a setting for each gear.)

    1. In Ontario at least there’s a book of set times that a particular procedure is supposed to take, and the shop just charges that multiplied by the shop rate, no matter how long it actually takes.  I guess it’s to keep dishonest mechanics from taking their time and charging three hours to change an oil filter, but in this case, it would be pretty much pure profit for the mechanic

      1.  Then of course, there’s the ascending scale from the base rate starting with ‘if you watch;’ ‘if you ask questions;’ ‘if you want to help;’ to ‘if you worked on it before you brought it here.’

        1. Between “If you ask questions” and “if you want to help” is “if you hang around in their waiting area drinking their coffee and looking impatient”

        2. Being a tinkerer myself, I am resentful of, but fully appreciative of the necessity for, those rules.

      2. The flat-rate-book is good, is necessary and protects the mechanic, and the the customer. Accomplishing the job in less time than the flat-rate-book is how an efficient and experienced mechanic makes more money than a less experienced or efficient one. Alternatively, the FRB protects the customer from being overcharged by the inexperienced or others.

  6. Rotating machinery scares me more than anything else that I’ve worked with, including a circa-1914 800-ton stamping press that could make car hoods in one pass.  Leave a chuck in a large drill press some time, and you’ll understand why.

    I had a physical flinch reaction to the video above.  That procedure should never ever be performed.

    1. Indeed.  When I bolted my horizontal-tank belt-driven (lacking a guard) air compressor to the floor in the shop, I bolted it belt-side toward the wall, and where the workbench would sit over the top of it.  It’s not impossible for foreign object intrusion into the belt, but it’s much more difficult with how it’s positioned.

      My ’95 Impala’s accessory serpentine belt can be changed in a couple of minutes with a simple 1/2″ socket on a breaker bar.  In fact, the car is still on its original belt (it only as about 12k miles on it and is garaged), and I keep a spare belt and the minimal tools to change it in the car.  I’m lucky, it’s a RWD sedan whose engine bay was designed for a belt-driven water pump and a belt-driven cooling fan, that later saw the engine revised (with the introduction of the LT1) to using a cam-driven water pump and an electric cooling fan, so there’s almost nothing in the way for changing the belt.  The routing is not that hard, but there’s enough to make it not a five second job, but it’s simple enough that just about anyone able-bodied in physically good enough shape to drive (ie, not someone paralyzed with a modified vehicle or the like) could change it.

  7.  That engine is missing a bunch of the original tin (the shrouds which guide the air to help cool the engine).  There’s supposed to be a piece that covers the lower half of the crankshaft pulley, including the big bolt that fastens the pulley to the crank.  If that was there, this trick would not work.

    There’s also a preheat hose missing, note the hole in the tin next to the right-side heater hose.  It was probably removed because they’re running a cheap aftermarket air cleaner that doesn’t accommodate the preheat hose.  At minimum, that hole in the tin should be plugged.

    Now, does anyone have a link to a 3-minute engine removal from an aircooled VW? That would be cool to see.

    1. Here you go:

      I seem to recall lots of spirited internet debates about whether the preheat hose was important or not. Some guys would toss it the instant they saw it, others insisted it was a critical component. 

      I think it’s pretty common for people to toss the tin around the timing pulley.. open the engine of any daily driver and I’d give a 50/50 shot at the tin being absent because it doesn’t really contribute to heat management. The pieces that seal the engine bay certainly are important though. 

  8. I like my Lycoming IO-360.   It’s like the Duplo version of this one.   Three hundred and sixty cubic inches in an air-cooled boxer four.   It sounds like two Harleys taped together.

  9. GAH!!!!  I miss my old VW so much.  So, so much.  It was crap, but man I just loved the sound it made when it was running.  There is just something about those old cars.  If I had one again, I might make a concerted effort to work on it.  

    1. My ex-wife’s sister had an old Karmann Ghia that she parked for a couple of years after the inevitable battery-under-the-seat fire.  Out of boredom I spent an afternoon dragging it out of the back yard (brake drums had frozen) and another afternoon getting the engine running again.  Fuel lines were shot (of course), so I fired it up with a glass jelly jar of gasoline on the roof gravity-feeding the carb.  It was amazing how satisfyingly simple that car was.

      1. Wow, that sounds like lots of fun and very satisfying.  Back when I had the car, I really just didn’t have the patience to do such things (ah, impetuous youth) nor the confidence to do something so mechanical. Now I think I value that kind of work a bit more, since I spend most of my time reading books or microfilm or writing – basically, I spend tons of time in my head…  Once I’m through grad school and (hopefully! knock on wood! let’s not jinx it!) gainfully employed, maybe I’ll spend time on something like this.  It’s good to know how to work on cars and with newer vehicles you just don’t get the opportunity. And engines I think are far too complicated anyway for most of us to work on regularly…

        1. Working on old air-cooled VWs is so much fun.  They’re not complicated enough to be truly frustrating, though the frequent maintenance required to keep them on the road as daily drivers means it’s hard to keep one’s nails clean for the entire week before something needs fixing or changing.  (Oil changes every 1500 miles… in 1994 I drove so much I’d have had to change my oil every other Saturday.)  But as a hobby it’s cheap and easy fun.  They’re almost toylike in their simplicity.

          If you have a VW (or are just idly considering getting one), I urgently recommend picking up John Muir’s How To Keep Your Volkswagen Alive: A Manual Of Step-By-Step Procedures For The Compleat Idiot.  Muir was an aerospace engineer for Lockheed in the 50s, and a tie-dyed-in-the-wool hippie in the 60s, and his manual is written for VW owners with no mechanical repair experience whatsoever.  It’s full of gorgeous hand-drawn illustrations by Peter Aschwanden rather than photographs, and the language is expressive, informative, hilarious, groovy, and accessible.  For example, he tells you that you don’t need to run out and buy a complete set of all the tools you’ll ever need, since he reasonably assumes you “don’t have the bread.”  Instead, you start with a few basic hand tools, and add to your collection as you need more specialized ones.

          I haven’t owned a VW in 15 years, but I still have (and occasionally re-read) this book.  It’s practically a graphic novel, it’s so entertaining.

          1. Wow!  That book is in the 19th edition!  I might just pick that up because I love VWs. Also, I can be a complete idiot about mechanical things.

            I think servicing a car all the time and trying to write a disseration at the same time are probably not really compatible activies, but I’ll finish the dissertation sometime, I’m sure.  It can’t consume my whole life for the rest of my life, right?

          2. That’s right.  Personally, I find car repair and restoration to be as restful as doing a crossword puzzle is for some people.  As long as I don’t need the car running again to get to work tomorrow morning (and the parts store is closed and it’s raining and a previous owner stripped a stubborn bolt head for me, and all those other similar aggravations), then it’s a great hobby to be able to turn off the day-to-day person-interactive consciousness and just exercise the quiet problem-solving brain and the manual dexterity.  Wonderfully restorative after a long day of intellectual abstraction!

          3. Muir’s book is a delight, and very much a Boing Boing kind of read.  I don’t regret getting rid of my VW (it was Satan in raspberry), but I regularly regret getting rid of the book at the same time.

          4. Donald – I was a little kid in the early ’70s — my parents had an old bug and an old bus…and this book. They were students and worked, didn’t have a lot of bread. My dad is _not_ mechanically inclined, but this book saved my parents a lot of bread, time and frustration. 

            Plus…I really think I was motivated to learn to read, at least in part, to be able to read the book that my dad used to fix our cars, and also because I was curious about the process that caused my dad’s mouth to go full-on sailor…seriously, his dad, who, after 35 years, was still in the Navy, told him to tone it down. And maybe get a trim.

      2. The under the seat fire is usually caused by contact between battery post and seat springs, it’s simple to prevent; just put a piece of rubber over the top of the battery. 

        1. That’s what did it.  My littler sister-in-law was sitting there when she started smelling smoke.  Nobody else had sat on that tiny little “seat” in years.  The Ghias in particular never should have had back seats.

          1.  All the Karmann Ghias I owned had masonite on the underside of the back seat, no exposed metal.

            Still my favorite car, honestly.  Although I love my new plug-in Prius, it just isn’t as elegant as Herr Porsche’s mechanicals stuffed into a Ghia designed tin can.

    2.  I didn’t know much about the boxer engine til I got my subaru sti. And I do love it’s rumble.

  10.  In my first bug, I had an underseat fire but not from the seat springs. There is a hole in the body where the positive battery cable passes through on its way to the starter, and there is supposed to be a thick rubber grommet that the cable goes through. That grommet was missing in my ride. The metal of that hole isn’t knife sharp, but it’s not dull, either. The insulation on my battery cable eventually wore through, allowing lots and lots of current to flow from the cable right to ground. It was amazing how quickly the cab of the bug filled with smoke, spiced up with the loud sound of electrical arcing. I nearly stained by britches!

    Another source of fires is the lack of another grommet, the one that the metal fuel line passes through from the underside of the vehicle into the engine compartment, through the aforementioned tin. Missing grommet, metal fuel line eventually wears a hole, spewing fuel all over the place.  That one’s scarier, but luckily, I haven’t experienced it, only heard about often.

    BTW, does anyone remember RAMVA? on usenet. Probably just a spam ghost town these days.

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