Timing chain/valve adjustment replacement on 280C

[Tomas7]

I am going to replace my timing chain and perform a valve adjustment. What's the best place for purchasing a timing chain and what else do I need while I'm in there? Are there any write ups on these procedures?

[kraakevik]

Replacing the timing chain on M110 engines requires finesse and luck. Chains are widely available for around fifty dollars with link. I'd suggest reading all the manuals on the procedure to decide whether you're up to the task.

A length of broomstick can be used to keep tension on the chain while you or your assistant feed the new chain in and the old one out. I tie thread to the E-clips on the master link and razor it off when secure--otherwise it's quite difficult to snap them on without losing one.

I have around a million miles on these engines and have had only one chain break. Unless there's an excellent reason to replace the chain I wouldn't tempt fate.

Best of luck


Tim Kraakevik
kraakevik@voyager.net
Four M110's

[Tomas7]

How about the tensioners, do they wear thereby affecting the slack and performance of the motor.

[kraakevik]

The chain tensioner ratchets one way against the chain rail to eliminate slack, which causes sudden death in these engines. The tensioners seem to last forever.


Tim Kraakevik
kraakevik@voyager.net
Four M110's

[mbbuff]

Why are you changing the chain? Do you suspect/know there is a problem? If so, what are your symptoms? If you're going to get in there though, change the tensioners. They aren't that expensive. Chances are it's never been done unless there's a zillion miles on it.

[mercmad6.3]

The chain needs to be checked every 80-100,000 miles. remove the cam cover and turn the engine until the cam marks line up with the marks on the cam bearing towers.
Then ,check on the damper where it lines up on the timing mark. If the timing mark indicates 5 degrees or more ,the chain must be replaced.
On a M110 it isn't breakage ,although I have bought a couple of nice cars cheap because they had broken chains, it's the fact that the engine will be way down on power because the cam timing is late and the ignition timing will be in the wrong place.
Replacing a M110 chain is a bit different to the other single cam engines and it pays to remove the rocker arms to make the job easier.

The tensioner is pressure fed and replacing it with the chain is the normal way of doing it.

[Tomas7]

Thank you very much.

[kraakevik]

There are also offset Woodruff keys available to relocate the cam sprockets to correct the cam timing without replacing the chain--but you still need to remove the compressor, tension the chain to verify the timing and then reinstall the tensioner so that it takes up the slack.



Tim Kraakevik
kraakevik@voyager.net
Four M110's