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[JamesV6CDX]

I changed the cambelt on one of my Omegas today.

When I removed the cambelt cover, and looked at the setup, I found this.

Can any eagle eyed OOF'ers spot what I'm talking about? (Clue, it's not a timing issue).

I wonder what the potential implications of this are.

It's corrected, now, and sporting a new kit, so good for the next 40k / 4 years

[Kevin Wood]

The orientation of the sprung idler looks a bit odd to me. Been tightened the wrong way to take the slack out?

[Shackeng]

There is something odd at 7'o'clock behind the red cam wheel.

[Migv6 le Frog Fan]

Its a while since I did one, and my memory is fickin shockin, but aren't the idler/tensioner the wrong way round. I.e. each one should be where the other one is ? 

[cam.in.head]

i take it you are referring to the earlier central top centre pulley style rather than the offset 2.6 3.2 type . or am i missing something other

[STEMO]

You left the locking tools in.

[Doctor Gollum]

Cracked rear cover next to alternator?

[Kevin Wood]

Hmm, and the shoulder on the bolt securing the bottom idler doesn't look like it's seated in the bore in the central part of the pulley.

[JamesV6CDX]

Hmm, and the shoulder on the bolt securing the bottom idler doesn't look like it's seated in the bore in the central part of the pulley.

Bingo - nail on the head

[JamesV6CDX]

So, looking closer up.

What has happened, is that one of the E14 headed bolts (for securing the tensioner backplate) has been used in the bottom idler.

The correct idler bolt (with the smaller E12 headed bolt) has been used on the backplate.

The thread, length, and pitch of these bolts are actually the same, but, due to the larger head on the E14 one, you can see below, it doesn't fit properly into the bore of the idler:



As a result, because it doesn't go into it's recess, the amount of thread protruding from the rear of the idler, is somewhat less:



Not sure what the implications of this could have been - if any

I wonder how effectively the head of the bold was securing the idler, on the basis that, not being in the bore, it doesn't actually have much area to purchase on (on the idler face)

It's an academic question, because I've corrected it all - I'm only asking 'cos I'm curious

[STEMO]

Hmm, and the shoulder on the bolt securing the bottom idler doesn't look like it's seated in the bore in the central part of the pulley.

That was well spotted, Kevin 

[Andy H]

I don't like the angle of the top tensioner - belt tension should try to turn the tensioner clockwise (which would cause the centre bolt to tighten if it ever did move). That tensioner looks as though it is ready to go the other way and loosen the centre bolt - it looks as though there is one tooth too many on the belt between cam 2 & cam 3.

If there is one tooth too many between cam 2 & cam 3 then it will be one tooth short on the run over the spring loaded tensioner - which might explain why the orientation of that idler looks odd.

[Kevin Wood]

I don't like the angle of the top tensioner - belt tension should try to turn the tensioner clockwise (which would cause the centre bolt to tighten if it ever did move). That tensioner looks as though it is ready to go the other way and loosen the centre bolt - it looks as though there is one tooth too many on the belt between cam 2 & cam 3.

If there is one tooth too many between cam 2 & cam 3 then it will be one tooth short on the run over the spring loaded tensioner - which might explain why the orientation of that idler looks odd.

Yep, that's also true.

[Kevin Wood]

So, looking closer up.

What has happened, is that one of the E14 headed bolts (for securing the tensioner backplate) has been used in the bottom idler.

The correct idler bolt (with the smaller E12 headed bolt) has been used on the backplate.

The thread, length, and pitch of these bolts are actually the same, but, due to the larger head on the E14 one, you can see below, it doesn't fit properly into the bore of the idler:



As a result, because it doesn't go into it's recess, the amount of thread protruding from the rear of the idler, is somewhat less:



Not sure what the implications of this could have been - if any

I wonder how effectively the head of the bold was securing the idler, on the basis that, not being in the bore, it doesn't actually have much area to purchase on (on the idler face)

It's an academic question, because I've corrected it all - I'm only asking 'cos I'm curious

With far less thread engaged but presumably the same torque applied (but, let's face it, on this job, probably just a couple of grunts) the bolt would have been much closer to failing. The smaller clamping area on the pulley would have done it no favours either. That could very well have ended in tears. Good job you got there first.

[JamesV6CDX]

I don't like the angle of the top tensioner - belt tension should try to turn the tensioner clockwise (which would cause the centre bolt to tighten if it ever did move). That tensioner looks as though it is ready to go the other way and loosen the centre bolt - it looks as though there is one tooth too many on the belt between cam 2 & cam 3.

If there is one tooth too many between cam 2 & cam 3 then it will be one tooth short on the run over the spring loaded tensioner - which might explain why the orientation of that idler looks odd.

That could potentially explain why, the timing marks all lined up, but the tensioner mark was below where it should be