2017 F150 Knocking possible cam gear issue- advice needed

[ccscout1]

Last week I noticed a slight tapping on my 2017 f150 XB both in neutral, idle and reverse. No lack of performance, I still get my top RPMS and speed. But now am afraid to run it until I can figure out the knocking. Background- This motor has 1,386 hours on it, I bought it with 1,059 last year. The last service was done 30 hours ago and I went with 20w40 oil. Timing belt was replaced at 1,000 hours. I listened with the cowling off and it sounded like it was right above the fuel pumps. I pulled the top cover off and see that my one cam gear has quite a bit of red dust on both the upper and lower portion and running it sounds like the knocking is coming right from that gear. Has anyone else had this? should I just replace the gear or what else should I be looking for? Looking for any advice- thank you. i also posted videos of it running on the yamaha owners facebook page, but have not gotten any replies in regards to these gears or the cam.

[TownsendsFJR1300]

Just looking at the dust on that cam gear, there's something failing / worn with it..

I'd suspect the splines on the cam eventually buggered up that gear- With the tension from the belt, pulling hard/keeping tight.


Note: My friends old Harley sportster, had the engine drive pully (aluminum, where the engine sprocket would be) fail, strip out inside again, from tension as there's no final drive CHAIN, but a belt..

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[fairdeal]

Very interesting.
The issue you have is, while not 'common',
nevertheless would be 'unsurprising' on the 2003-2010 F225 -
which uses a very similar cam gear.

But this is the first I have ever heard of it on an F150.

The problem is simply that the cam gear is 'wearing' -
if you replace it now before it "fails"
there will be no collateral damage, no additional expense.

This is the part for your engine:

https://www.boats.net/product/yamaha/63P-11537-00-00


Here is a similar gear on an F225 - creating the 'red dust':




Here is what happens if you ignore it:

[ccscout1]

Would this also explain the ticking noise that i am hearing? Is this simply a bolt and unbolt gear while also changing the timing belt? does this gear hold a bearing of any sort?

[fairdeal]

Would this also explain the ticking noise that i am hearing? Is this simply a bolt and unbolt gear while also changing the timing belt? does this gear hold a bearing of any sort?

Yes, the ticking noise is the gear itself,
inside that 'plastic' gear is a large steel 'washer',
the steel washer is eating away the plastic,
creating 'space' that then makes a knocking sound,
and grinding the plastic into the red dust.

To deal with it, buy the new gear;
rotate the flywheel so it and the gears are on their timing marks,
then release the timing belt tensioner,
remove the bolt that holds the bad gear, and replace it.
Then check the timing is correct, and re-tension.
That's it.

Since you just replaced the belt 300 hours ago,
personally, I wouldn't replace it again.

Any bearings are on the camshaft itself,
below the gear,
you don't need to bother or worry about them.

Its a really simple fix,
so long as you do it now before the gear comes apart:

wait until that happens,
the engine comes to a stop, and,
with an interference engine like the F150,
you have the potential for bent valve/damaged piston

[ccscout1]

Can you provide the torque specs for this gear? Once you loosen the belt, how to you hold the gear so it doesn't move while removing the bolt? Thank you

[TownsendsFJR1300]

Capture.JPG


^^^, from my 2006 F150 shop manual.