On 4/18/2001 "Brian Hollands" <bholland@hayes.ds.adp.com> wrote:
>2, Consider removing the lower tensioner guide, as it is not all that
>necessary
>
>I spoke to Mike Kerr about this and he recommended against this mod on the
>U20 as the guide helps lessen the load on the nose of the Jackshaft. FWIW
>I removed the lower guide from my engine last time I had it apart. The
>lower timing chain had lost the front and rear links on and had only the
>middle link (center of the double row chain) holding it all together when
>I pulled it apart this time! Could have been a faulty chain but that
>guide is going back into my engine this time.
>
Brian,
I remember seeing a post from Mike Kerr about this. Something about the
possibility of a sheared jackshaft because of the load. The way I see it,
there's still a load on the jackshaft nose even with the lower guide. And
if there's slop in the chain, I think chances are better of it breaking off
the lower guide than of snapping off the jackshaft nose. Then again, if
there is that much slop in the chain maybe you're better off with a broken
guide, if you're lucky enough that the broken piece falls cleanly into the
oil pan without getting caught up in the chain. On my 2000, the broken
guide caused some damage - as it got chewed up, metal fragments ate up the
crank and rod bearings and threw a rod.
So how many accounts of busted jackshafts have we heard of versus broken
lower guides? In any case, I recommend checking your timing gears and
chains every so often, and swapping them out every 60,000 miles for sure.
Fred - So.SF
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