Date registered: Feb 2010
Vehicle: 1972 280SEL daily driver. 904 Dark Blue with cognac interior. euro 4.5 engine
Location: Williamsburg, VA
Mentioned: 3 Post(s)
Quoted: 34 Post(s)
More Scary Timing Chain Guides
Recently replaced the 4.5 in my W108 with a "new" one. I decided to play with the old block and have torn it down to nothing but the casting. Some of the things I've found are a bit disturbing.
In the upper head, everyone says the old 4.5 guides are best because they are aluminum and won't break. Mine had one broken in two.
Tonight, I finished tearing down the block including removing the front cover. There are two bolted in guides inside the front cover. They bolt to the block. One of mine is all aluminum and the other is aluminum with a backing. The all aluminum one was cracked all the way through and separated into two pieces when I removed it. The aluminum one with the backing has a through crack in the backing and was beginning to come off.
Not sure of the history of this engine other than the car seems to have about 350,000 miles on it by best guess. It would appear there has been some chain slap as the left head had some wear in the chain area.
Just glad it is not in my car anymore.
Thought I would share.