How do I detect camchain wear?

[McCabe-Thiele (Ted)]

I am aware of the tank track test for primary drive chain wear  is there a simple  test for the 500 cam chain that tells you it need replacing?

[Bryanj]

Not realy when its in bits Ted, but compared to primary chain cost is nowt

[K2-K6]

Wrap the chain round the cam sprocket and pinch together at the meeting point, then try and lift the chain off the sprocket opposite this last point (the pinch point) to see how far you can move it, anything more that about 1mm and it's knackered really.

Obviously this uses the set pitch of the sprocket to match the chain pitch link by link, too much movement confirmation of each pin/bearing having wear such that accumulative variance allows that lift to be observed.

Much more simple than it's taken to describe, but as Bryan indicates, not really worth not changing if it's apart.

[McCabe-Thiele (Ted)]

Between my ears I knew I should replace it as a matter of routine it makes sense when the engine is in bits.

[K2-K6]

There's interesting comparison between the two chains Ted. The tank track one for primary "Hi-Vo" chain is because the chain links are restricted from bending backwards by their geometry, the opposite of why they are often called silent chain because that same geometry layout causes the drive faces to change shape as they go round the drive gear, making it difficult to judge when bending round the gear as they effectively take up wear slack to match the tooth form. The tank track test just illustrates the amount of slack in there when they are not wrapped around a gear drive tooth form.

The cam chain will of course bend in both directions easily and not give the same illustration to check pin wear. This type can be tested sideways to substitute for that characteristic.  Just hold chain runs together and point the chsin out sideways ( pins orientated in the vertical plane) from your hand, how much the chain links now bend downward indicates just how worn each pin/bearing has in it.

Useful from an interest point of view if you compare your new chain  with the old one to see just how much it had worn.

From a lifing point of view, the primary wears more quickly in most part because it was never developed to run in higher viscosity engine oil but 5 viscosity ATF as bearing site flushing is optional for the thinner oil (4WD transmission run these to big mileage in ATF) and probably a principal contributing component in any grey ferrous sludge in sump pan on them.

[Oddjob]

I've found Ted that whilst it's standard to replace the chain whilst the engines apart it's the tensioner which could be the real problem, I've got quite a few of them now and most show some sort of damage, most common is having the tensioner actually bent out of shape, very common to see the bottom section well out of line with the top and normally bent inwards. Also damage to the cups where the damper rubbers go, gets damaged by the primary chain if it's very worn. All these stop the tensioner working correctly.

TBH you don't tend to notice it until you have 2 or 3 side by side and you can see the difference in the shapes.