Chrysler 383 timing chain recommended replacement?

[NWPT70]

I have a 1970 Chrysler Newport with believed 55k oringinal miles. Is there a recomended mileage people are replacing these chains? Has anyone had a timing chain fail on these motors? The car I purchased came with a bunch of NOS parts and a timing chain and sproket were included. The previous owner rambled on about how I should probably change the chain since 1970 the chains or sprockets were plastic lined? Can someone shed some light or debunk this claim? I am mechanically inclined but have never replaced a timing chain on a 383 before.

 

[detmatt]

The cam sprocket does in fact have plastic covered teeth. I pulled the original out of the 440 in my '67 Imperial and it was in near perfect condition. If the chain is stretched out and your timing is erratic because of it then replace it. If it's not broke don't fix it.

 

[Big_John]

I have seen them fail. The plastic gets old and brittle and breaks away from the sprocket. The chain may jump a tooth or I have seen where the plastic shards clog up the oil pickup.

The good news is the engines aren't like the new zero clearance engines that you have to deal with now. If you have a chain skip a tooth on your 383, the chances of a valve hitting a piston are pretty much zero. It won't run though (or run really bad) ... and can drive you a little crazy figuring the problem out.

So... it's up to you. It's not a bad idea to do, but as Matt said, it may just be fine the way it is.

 

[NWPT70]

Thanks for the expertise guys!

 

[CanCritter]

if cars running fine leave it alone...next time you gotta get on down in there ie water pump ect would replace it then otherwise would leave it alone...would be concerned on how long the plastic would hold up ie brittle ect...if you've been running it at length you should be fine...figure if its gona fail because of sitting it would do it once its restarted and run for a bit early on

 

[cbarge]

If it is not broke,do not fix it.
The nylon teeth were designed to reduce noise-nothing else.
To set your mind at ease,you can check how much slop is in the chain without tearing the face of the motor off.
Using a timing light,check your timing,if the mark is staying put with very little movement,no need to go further.
If it is jumping around,shut her off,pop off the distributor cap.set the timing mark at TDC . Then rotate the crank by hand in the opposite direction WATCH THE ROTOR BUTTON and see how much it takes for the button to move. If you moved the crank by 1/8 turn or more ,you have a loose sloppy timing chain.
For replacement,my preference is a Cloyes double roller. Both my 383 and my 440 had them installed no problems.
Hope this helps.

Cheers

 

[65sporty]

If it was mine I would change it for peace of mind, one less thing to worry about. But I have changed timing chains on many engines so I am very comfortable with doing the job.

 

[RemCharger]

.....then you start thinking about the cam...... lol

 

[cbarge]

.....then you start thinking about the cam...... lol

Then the lifters,then the pushrods,then the heads....It can snowball in a hurry,LOL!!