On Tue, 19 Apr 2005 06:14:00 -0700, jim beam <nospam@example.net> wrote:

>George Macdonald wrote:
>> On Mon, 18 Apr 2005 05:56:59 -0700, jim beam <nospam@example.net> wrote:
>>
>>
>>>George Macdonald wrote:
>>>
>>>>On Sun, 17 Apr 2005 07:45:58 -0400, Imminent Vengeance <me@privacy.net>
>>>>wrote:
>>>>
>>>>
>>>>
>>>>>George Macdonald wrote:
>>>>>
>>>>>
>>>>>
>>>>>>Depends where you live but that suspension system is prone to broken front
>>>>>>springs in the frost belt - the spring breaks just where it enters the
>>>>>>perch on the shock. Because of where the break is, you probably won't even
>>>>>>notice any difference in ride/handling but you might hear a "doink" when
>>>>>>you get out of the car on the side with the break; you'd definitely hear
>>>>>>the "doink... doink" when you jack the front up. The break *can* put some
>>>>>>side force on the shock which will wear it out quicker.
>>>>>>
>>>>>
>>>>>The only time I broke a spring on my '93 Accord, it was at the other end of
>>>>>the coil, at the top where it enters the strut mount. But I think this was
>>>>>the result of that corner of the car jumping a huge curb while swerving to
>>>>>avoid a bad driver.
>>>>
>>>>
>>>>The break often happens on a violent bump but the root cause is usually
>>>>weakening of the metal due to corrosion where water/salt gets through a
>>>>hole in the epoxy coating of the spring. The upper spring seat has a
>>>>rubber doughnut in it so there's no wear of the epoxy there. I've heard of
>>>>the upper end going but AFAIK the lower is more common because of epoxy
>>>>wearing away where it contacts the metal of the perch. If you live in a
>>>>"corrosion area" it's worth checking springs for nicks in the epoxy...
>>>>which *can* be caused by some of the (cruder) tools used to compress the
>>>>spring, e.g. when swapping shocks.
>>>>
>>>
>>>i've seen brand new springs with such nicks. bad [neglectful] handling
>>>handling at the factory. as you say, corrosion pitting starts & that
>>>causes a stress riser that initiates fatigue. it's the fatigue cracking
>>>that kills the spring.
>>
>>
>> Funny thing is I've always thought that spring metal can easily be made
>> fairly corrosion resistant.
>
>sure, there's all kinds of non-ferrous springs, but they're fiercely
>expensive. i know honda springs don't seem "cheap", but believe me,
>they are compared to the alternatives. also bear in mind that steel is
>relatively high modulus compared to other materials and silicon/carbon
>steel typically used in auto springs has a very high yield point
>compared to most fatigue resistant stainless steels. lastly, spring
>wire has to be comparatively soft for the forming phase, then heat
>treatable to become hard and resistant to yielding. stainless steels
>exist that have these kinds of hardening reactions, but they're a big
>step up in cost.

I wasn't talking about stainless or non-ferrous - there are alloys of of
"steel" which corrode much more slowly than others. This is a problem
which, while not unique to Honda, is a rather glaring one... not to mention
that the epoxy coating seems like a bad idea, given the evidence.

>> If Honda thinks they can skip that because of
>> the epoxy coating, somebody there is dreaming. The Lyle tool I used to
>> replace my springs really did a number on the brand new spring coating -
>> tried to patch with epoxy glue and hoping it'll hold for a bit.
>>
>just rust resistant paint works fine. trouble is, once you have some
>corrosion, you have pitting & therefore potential fatigue crack
>initiation. strictly speaking, springs in that condition should be
>replaced, but i can't say i'm a strict adherant to that rule. depends
>on mileage & condition.

Did you miss something here? This was a brand new spring which was marred
by the tool - no question of corrosion having started.

>interesting you mention the lisle tool. i was extremely unimpressed
>with the principle of that device, for the reasons you're describing
>happened. i therefore built my own - does not touch the spring at all!
> i'll email a photo to tegger.

I chose it because it *looks* safer than some others, since the loops
cannot break loose from the spring coils under load. I found on use that
the screws "machine" a "thread" into the collars, thus reducing their
effective thickness - IOW safety may not be what it appears.

--
Rgds, George Macdonald