Date: Sun, 09 Apr 2000 11:20:31 -0400 From: dscvnopsamltranet.com (Robert Anderson) Subject: Re: Timing Chain
In article <8coce5$e1d$1nopsam1.deja.com>, coxinga <coxinganopsameja.com> wrote: --snip-- > After the timing chain came off. I finally realized what happened. > The oil pump, balance shaft chain sprocket, and the timing chain > sprocket, are all held on the crank shaft by a Woodriff key. It is a > crescent shaped key fitted on a slot on the crank shaft. What happened > was the timing chain sprocket, being on the inside, engages on only the > tip of the crescent. Overtime, the small area at the tip of the > crescent failed in fatigue. (Does SAAB engineers has the wisdom to > design the key so it failed just a little ove 100k mile? I wonder.) --snip-- Woodruff keys are locating devices. They are not intented to carry load of the sprocket. If the woodruff key failed, it indicates that the timing chain sprocket was loose. /Bob