How to tell when timing chain needs replacement?

[drmayf]

Not new to fords, but new to the Vulcan 3.0L engine. I have replaced many from 260 to 351 v8 engines and also the big FE engines as well. All those had very little slack in the timing chain. But when I removed the timing or front cover from my Ranger, owned since new, this chain seems to have a lot of free play or slack. Engine only has 84000 miles on it. So the question is, is slack in the timing chain normal or does this puppy need to be replaced. I am that point in disassembly and installing one would be relatively easy. But if not needed...

So, what is the recommendation for me regards the chain "tension" and replacement? Is there some kind of slack measurement or ? Reply quickly as I have to order one.

Thank all ya'll
drmayf
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drmayf
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[cbxer55]

Don't know the answer as to how to tell if it needs replacing. My 98 3.0 has 153,000+ miles on it, no issues at this time. No indication at all that it needs a new timing chain. I would say that the cam position sensor is more apt to need replacing before the chain ever will. I've heard there's a noise that 's a giveaway when that needs to be replaced. With my bad hearing, and a hearing aid that has noise cancelling, I don't know that I'd hear anything that would tell me something needs replacing.

 

[RonD]

OEM 3.0l Vulcan timing chain runs $30-$40 on Ebay

If you are asking then it might benefit to get a new one, it will have less slack, BUT(big but)........

Timing chain issues on the 3.0l Vulcan are pretty much non-existant, so does it need one?
No test that I know of, probably is one just never read about how much slack movement is too much.

I would not replace it with 3rd party chain no matter what, new OEM or leave it alone

 

[drmayf]

Thanks for the replies. I have decided to leave it alone for now. Using the "if it ain't broke....." philosophy it will probably last longer than me.

drmayf

 

[pjtoledo]

ford manual has a procedure to check wear. it amounts to the how far the crank moves while the cam doesn't. limit is 6 degrees of crank rotation.

 

[Rearanger]

ford manual has a procedure to check wear. it amounts to the how far the crank moves while the cam doesn't. limit is 6 degrees of crank rotation.

How would you measure that? If the crank is turned to align cam/crank sprocket marks would the cam mark be lagging 6* when the crank mark is aligned?

 

[pjtoledo]

per Chiltons, same as my Ford book:

remove left-driver side valve cover
loosen #5 cylinder exhaust rocker arm, 4th one back, and move out of way
mount dial indicator on pushrod
turn crank clockwise until #1 is at TDC, harmonic balancer should be at 0
timing chain should now be tight on right side, 4-5-6
zero dial indicator
slowly turn crank CCW until dial indicator moves, smallest movement that can be detected.
check how far harmonic balancer timing mark moved, should not exceed 6 degrees.

6 degrees on the short radius of the crank gear isn't much, the timing dots will still be closely aligned.


I would think that devising a way to lock the cam and measure the crank movement would also work, if the front cover is off.

as the cam rotates thru opening-lobe vs closing-lobe actions it will snap back and forth causing the timing to jump around.

 

[det107]

I had a 100,000 mile "tune up". It consisted of replacing the water pump, idler pulley, new belts, new gaskets at a friend's garage. It was noticed then that the timing chain had slack. Of course sprockets & chain was replaced.
I use this truck for hauling heavy junk & there are times it idles for the longest time.
But the timing chain slack is still a mystery-

 

[adsm08]

There is no specified service interval or amount of play, like with the belt, in the book. The answer to the question is "When the front cover comes off".

 

[Rearanger]

It's been a long time since I owned a timing chain vehicle, but when I did it never needed replacing. New vehicles now have gone back to chain over belt - a welcome change, except for the repair shops.

I'd think for checking slack just pinching the chain between the sprockets and measuring the distance should be enough, but you'd need a spec.

Looking at pjtoledo's check procedure it's easier to just replace.