CV Boots - Why O Why do they make these things out of rubber?

Discussion in 'General Motoring' started by Be, May 7, 2005.

  1. Be

    Be Guest

    I have searched the web for the phrase "silicon cv boot" and the only site I
    found showed a radio-controlled race car model that someone had hand-made.
    It featured silicon cv boots.

    Now why, on this very critical item, won't the parts manufacturers use
    silicon rubber instead of the crappy standard rubber that ages and tears so
    easily? I can purchase a silicon oven mitt from Bed Bath & Beyond - and it
    is obvious that if this material can tolerate extreme temperatures and not
    fail, it would be the perfect material to use for CV boots. It is supple
    and strong.

    You would think also that this would be at least an obvious niche that high
    performance parts suppliers would fill, if not the standard parts guys. I
    can buy all kinds of braided metal hoses, etc. to decorate the engine, but
    not a silicon CV boot?

    I know the answer... It's like asking why don't the drug companies finally
    release a cure for herpes - because they couldn't continue selling the
    ultra-expensive topical treatments. But making a silicon CV boot wouldn't
    require FDA approval, and some smart parts company could make a mint
    providing this part - if they could create demand from the ignorant

    [Of course, I have entirely skipped the discussion of why there's so few
    rear-wheel drive cars available, which would eliminate the need for CV boots
    and joints altogether. ]

    Can someone clarify this a bit for me?

    Be, May 7, 2005
  2. Be

    halo2 guy Guest

    Maybe silicone is strong but it is not indestructable. Who is to say that
    it will last longer than a regular cv boot?

    I have a 1996 Accord with 129k on it and have the original unripped cv
    boots. 9 years is quite satisfactory for a cv boot. It isn't like they
    have to be replaced frequently.

    Maybe urethane would be better. After all they make bushings out of it.

    Also if the drug companies could make a drug to cure herpes they would.
    There is more money to be made off of curing herpes than treating it. I
    work in a pharmacy and we hardly dispense any antiviral products except for
    the occasional shingles outbreak.

    I am surprised however that there isn't a parts company out there promoting
    colored silicone boots or other material to all the ricky racers that think
    colored items actually make a fucking difference.
    halo2 guy, May 7, 2005
  3. Be

    TeGGeR® Guest

    They do use a different material now. The boots I've currently got on my
    '91 Integra's original CV joints are some sort of plasticky material. They
    are OEM for the new Civics, which happen to have the same size CV joints.

    This plasticky material is supposed to last much longer than the old-style
    ones. I notice the new boots have a very different profile than the old
    ones. The new ones have a radius at the bottom of each pleat, and have
    sharper points on the pleats as well.

    CV joint boots are subject to weather, steering stresses, road impact,
    salt, and budgetary constraints. Only the last could be applicable to oven

    Since you are not a chemist who understands polymer technology, you have
    absoultely NO way of knowing whether what you're calling "silicon" is even
    remotely suitable for CV joint boots.

    You never looked at the boots and one broke on you, didn't it?
    TeGGeR®, May 7, 2005
  4. Be

    Be Guest

    You are correct - that's why I posted the statement here. I am perfectly
    fine with being enlightened and shown the error in my thinking or
    assumptions. That's how learning takes place. I am quite capable of coming
    to terms with the possibility that the material that is currently used is
    actually the best possible choice.

    But when I hear that some folks have to have the CV boots replaced every
    couple years, I wonder...

    Be, May 8, 2005
  5. Be

    Brian Stell Guest

    I'm not sure it can really be considered a critical item. Brakes are
    critical. If they fail it can easily be life threatening. Probably
    could consider fuel and ignition critical (could be dangerous to be
    stranded somewhere; ie: on the railroad tracks or in an intersection).
    Wheel attachment and steering are critical (hate to lose any of them).

    But cv boots? I'd guess even when they fail the car will continue
    to run for a long time. Of course this will accelerate the failure
    of the cv joints but my experience is that cv joints complain
    (noise, vibration, etc) long before they fail.

    For non-critical parts the manufacture has to balance reliability
    against initial cost.
    Probably because they don't show when the hood is up. No flash
    It's probably a cost issue. I don't generally hear of people needing
    to replace the cv boots all that often (at least among people who
    buy new cars. And I doubt that manufactures care much about people
    who buy used cars ;)

    Just out of curiosity: what kind of car (I assume you own it) has the
    cv boot issue?
    Brian Stell, May 8, 2005
  6. Be

    Jim Yanik Guest

    They probably drive over every piece of debris on the highways.
    Jim Yanik, May 8, 2005
  7. Be

    Be Guest

    My daughter's 1995 Civic; however, I have had other cars that needed this
    repair. I had a 1992 Lexus ES 300 that went through a CV boot by1999 (but I
    had only owned it since 1998 and it was one of those so-called "certified
    pre-owned" models; I also had this repair on a 1997 Altima in early 2004.

    I have a 2001 Odyssey (with just 35K on it) that doesn't have this problem
    (yet). I'd like to know what I can possibly do to make these suckers stay
    in top shape and not crack/tear/dry out. Would some kind of silicon spray
    help at all?

    And when you think about it, why in the world would something like an
    Odyssey even HAVE front wheel drive to begin with? A big, heavy car would
    do fine with rear wheel drive.

    Be, May 8, 2005
  8. Be

    TeGGeR® Guest

    It's a problem, but not one that conspiracy theories explain.

    CV joint boot failure on a Honda and most other Japanese 2WD cars takes a
    couple of years from the first sign of cracking to when it splits wide
    open. This gives a savvy owner lots of time to occasionally inspect the
    boots at each oil change, and deal with it before the CV joint gets exposed
    to the weather.

    CV joint boots have a tough life, subjecting their polymers to unique
    stresses unseen even by the tires. Every time the wheel rotates, the
    bellows flex. It's a bit like bending a paper clip back and forth until it
    breaks. Cold weather, steering, and drive axle angles all conspire to
    destroy the boot through simple, repeated flexion.

    Some vehicles, such as AWD Subarus, appear to have shorter CV boot
    lifespans than Hondas, probably due to their relatively extreme drive axle
    angles relative to the wheel's axis.

    Considering the major strides automakers and their suppliers have made in
    the longevity of most components -- from engines to shock absorbers to
    tires to transmissions to body steel -- over the decades, I suspect the CV
    joint boot problem is primarily one of being unable to find a cost-
    effective substance that has the characteristics the CV joints need, but
    that still resists cracking for the life of the car.

    Remember when shocks and tires had to be replaced every 20,000 miles?
    Remember when engines and transmissions rarely made it past 100,000 miles
    without a rebuild? Remember when body steel would perforate in five years?
    TeGGeR®, May 9, 2005
  9. Be

    TeGGeR® Guest

    No. Nothing you can do.

    Check them every oil change. Replace about a year after the first sign of
    TeGGeR®, May 10, 2005
  10. Be

    Be Guest

    In that case: attention all car makers - please make rear wheel drive common

    Be, May 10, 2005
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