Hi Anwar,
Soot loading is irrelevant to subsurface fatigue failure of the
bearings. If you look at any pics of bearing's that have failed in that
mode there is generally little or no wear on the bearing surface it is
just that the bearing has fallen to pieces. A worn out bearing will show
scratches and or scuff's in the direction of rotation and look as though
someone has gently worked away at it with some fine sandpaper to wear it
away (see top left pic here that is normal wear
http://www.sacskyranch.com/eng219.htm, note the bearing to the right. It
is not just cruisers that have that failure mode, aero engines are
susceptible too especially since they use an extremely simple old style
additive package by law).
Extreme soot loading will cause lots of other problems long before it
causes bearing wear. The 1HZ is indirect injection and it's soot loading
(due to the naure of indirect injection) is typically 10-20+ times as
high as the facory turbo's yet subsurface fatigue failures of there
beb's are extremely rare.
The very fisrt one I saw was a NZ new one that was serviced by the
dealer every 5000km at the same dealer for every service from new and at
about 4 years old and 160,000km it ran a big end post bearing failure.
It was never used off road never towed anything just used as a large
family car. I don't know whow API are but it sounds like you should
speak to someone more knowledgable about cruisers like Maarten at
All-American in the Netherlands. If you are worried about your own car
either pull the sump pan and have a look or do an oil analysis every now
and then and look for a trend line of increasing levels of aluminium or tin.
Cheers,
Craig.
Anwar Shah wrote:
> Thanks John
>
> That about what ties in with what API told me when I took the truck
> for them to cast their eyes over it. They said they only saw one or
> two failures a year, mostly from vehicles that were neglected or
> abused (some local contractors persistently tow 7 tons with theirs).
> Aside from that it just seems that thorough maintenance, keeping the
> fuel system periodically flushed, and getting smoky exhausts treated
> early will avoid trouble. Smoky exhausts, beyond the normal turbo
> related enrichment, will cause deposits to blow-by, getting into the
> crankcase and the BeBs.
>
Snip.
> Anwar
>
> ------------------------------------------------------------------------
>