Is my timing chain loose on my V8 4.6L? | Page 2 | Ford Explorer Forums - Serious Explorations

  • Register Today It's free!

Is my timing chain loose on my V8 4.6L?

Does 4.6L use a hydraulically actuated tensioner like 4.0L? Where is it? If yes, wouldn't slack be present on coast side of chain when engine off? That was one of the first questions at the beginning. No tensioning is needed on "drive" side of chain, as it's pulling like hell against valve springs. "Coast" side reflects slack left in chain. Slack increases with time as all those pins in holes wear, effectively making chain longer, therefore looser. So, a hydraulic "tensioner" pushing the "looseness" in the chain against some form of backing, removes possibility of chain "whip", and rattling noise.

Chains get the job done. They wear out. They get longer when they wear out. Time was, to test a worn timing chain, you laid it out on it's side, held at one end, if it formed a curve, it was shot. What bullshit! I saw brand new chains lay over in a curve!

Anyhow, gears are better. OHC diesels use them. Trying in vain to find pics of Cat 500 HP truck eng., experimental then, in our dyno lab. Used a big gear train. Amazing engine, ca. 1967. imp

Yes, these are hydraulic tensioners but here is a built in spring loaded ratchet and as the chain stretches or the tensioner arm wears it ratchets outward and cannot retract. This is what holds the tension when there is no hydraulic pressure which is good enough until oil pressure develops for hydraulic pressure.

See the tensioner on the right side of this pic. You can see where the chain ground down the top of this tensioner after it the chain wore through the tensioner arm.