sloppy timing chain question

[deadflo]

Yesterday I mentioned on another thread that my mechanic had found some damage to my chain guide and problems with the chain(on the 71 Z). I went over to examine it and can confirm the chain was real loose on the side that should be tight. (the drivers side)

The top lip of the guide was gone too? (down into the front of the engine or oil pan???) Anyway the car has been running ok.

When I went home I pulled the valve cover off my 79 ZX to compare the chain tension. It was definitely tighter.

OK, so the question is: Is this something we could solve with the method shown in the Z therapy vid where Scott moves the chain to different sprocket holes?

Or should I just get a new timing set? Again it looks like the very top of the guide, about a half inch, is gone(somwhere). I really don't know how long the timing set has been on the car. The head is not original, and I beleive the car to have 210 K miles on it. By comparison the 79 ZX has 169 K on it and again that chain is much tighter.

[MikeW]

OK, so the question is: Is this something we could solve with the method shown in the Z therapy vid where Scott moves the chain to different sprocket holes?

Or should I just get a new timing set?

From your description it sounds like it could have been fixed by moving the sprocket to one of the other two holes but that it's probably too late for that now that you've got damage. You shouldn't keep using a chain that's been rubbing the guides enough to damage them and the chain itself.

[deadflo]

OK Mike, thanks for the input.I guess I can make the excuse I havent had the 71 Z all that long(2 years). What should I do to monitor the condition of the chains in the future?

[MikeW]

The timing chain simply stretches over the years. Just like with most new cars where you have to replace the timing belt every 60K-100K miles with a chain it needs to be checked and adjusted as needed. It may well be that your timing chain was already stretched when you bought the car and you simply had no idea that you had a potential problem looming. It's not something you really need to worry about at every oil change, for instance.

[Ed]

Not really sure about the damage you mention to your chain guide. Is it worn away? And you are talking about the tension side of the chain correct, not the slack side.

Here is a real good write up about timing chains:

http://www.classiczcars.com/forums/showthread.php?t=19579&page=3&highlight=timing+chain+notch

First you should check your chain and see if you can or if it needs to be adjusted.

FWIW there have been times where I turned my engine off after running it and when I inspect the chain there is a little slack on the tension side. Personally I think it happens when you park the car leaving it in gear. When the car rolls back a bit it rotates the crank assembly just a hair but the camshaft stays put. Thus resulting in a little chain slack.

[deadflo]

Ok, well im kind of wondering what you need to do to check it for stretching....

[deadflo]

Well like I said it is on the normally tight side and really different than my other Z. The guide is missing about half an inch from the top. Anyway thanks for the other link to the thread on dealing with removing ther timing set. I am still wondering if there is a good guide for how tight the chain should be if I check it every year or so?

Not really sure about the damage you mention to your chain guide. Is it worn away? And you are talking about the tension side of the chain correct, not the slack side.

Here is a real good write up about timing chains:

http://www.classiczcars.com/forums/showthread.php?t=19579&page=3&highlight=timing+chain+notch

First you should check your chain and see if you can or if it needs to be adjusted.

FWIW there have been times where I turned my engine off after running it and when I inspect the chain there is a little slack on the tension side. Personally I think it happens when you park the car leaving it in gear. When the car rolls back a bit it rotates the crank assembly just a hair but the camshaft stays put. Thus resulting in a little chain slack.