The Ford Barn

Tom Wesenberg · 12-22-2014, 11:49 PM

You changed a head gasket and 1 valve, then the noise started. Did you replace anything else at that time? The new valve would have increased pressure on #3, so could that have started the piston slap?

I'd probably replace the timing gear and keep this as a spare. If the new gear doesn't solve the noise, then you have a good spare gear. If the new gear solves the noise, then you can sell this mint gear on ebay.

PC/SR · 12-23-2014, 12:52 AM

Well, it's a good mystery (to us, to you an PIA). Please keep us advised.
I am trying to tie it in with the change when inserting the plastic bolt (I have not heard of that before, a neat diagnostic device) and surmise that if there is a wobble, the plastic bolt might change the angle of contact with the crank gear. With .008 clearance anyway (didn't anyone check that when the engine was assembled?? But hey, it changes the cam timing) a wobble may be enough to put it over the edge and make noise. At this point I would try a new cam gear.
Another long shot, as I recall, there is about .125 clearance between the gear and the cover bolt outside metal. Quite a bit, but maybe......something may be hitting. Ya got me.

SAJ · 12-23-2014, 03:08 AM

TOM, I reseated all the valves, after truing everything with my valve resurfacer. Changed no. 3 exhaust valve with no 2 because 3 was a tiny bit thinner now and no. 3 runs hotter and leaner. Put in new head gasket (BEST brand graphite). Nothing else.
TBIRD, will look inside all with my scope and see what is what. Compressions are still 96 to 98 WOT hot, with 2 and 3 the 98's as they were immediately after the seizure 8000 miles ago. Knock developed 4000 miles later and I have run with it for another 4000 miles - I just checked all my records properly. It got worse after I replaced the spring and plunger with the bolt I think, removing some damping friction from the gear I guess.
PC/SR I will measure the wobble with a DTI tomorrow and the deflection when I push on the gear, which is quite a lot- I certainly saw .010 deflection when levering with a screw driver when the front cover was on.
The gear nut is so tight I cannot get it off with a 30 inch power bar and risk the clamp I used damaging the gear. I will have to remove the radiator and shock it off with a pneumatic rattle gun etc.
There is nothing I can see that can hit inside the cover. I guess it is a worn fibre gear, maybe set up loose in the first place. Schwalms have a great reputation though.
I will order 2 fibre gears , one oversize and see what happens. I think trying a metal gear might result in more noise, but I will get one as well.
Thanks again
SAJ in NZ

Tom Wesenberg · 12-23-2014, 03:41 AM

If you use an impact gun to unscrew the nut, aren't you afraid of damaging the fiber teeth?

SAJ · 12-23-2014, 04:11 AM

TOM. I will put a clamp on the gear and hope it will shock off. It may well damage the fibre gear but the steel gear should be ok.
Can you suggest how else to get it off? I have never used a jamming rag on fibre gears and suspect tightening them like this is why so many fail. I dont want to pull the camshaft out really and get it in a vice.
I guess this fibre gear is no good anyway if worn.
SAJ IN NZ

George Miller · 12-23-2014, 08:44 AM

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Quote:

Originally Posted by SAJ

TOM. I will put a clamp on the gear and hope it will shock off. It may well damage the fibre gear but the steel gear should be ok.
Can you suggest how else to get it off? I have never used a jamming rag on fibre gears and suspect tightening them like this is why so many fail. I dont want to pull the camshaft out really and get it in a vice.
I guess this fibre gear is no good anyway if worn.
SAJ IN NZ

Lets hope the play is in the gear, and not in the main bearing center line. If the mains are off .003 or .004 you will have to get a over size gear.

Tom Wesenberg · 12-23-2014, 11:09 AM

I've only changed a couple gears while the cam is still in the engine, but I have used a rag to jam the gears and not had a problem. With the cam out of the engine I will clamp it between a couple wood boards in a vice, then use the impact gun on the nut.

Zener424 · 09-21-2016, 06:19 AM

For further followup on this thread, refer to post #14 in this thread:
http://www.fordbarn.com/forum/showthread.php?t=204993

12-22-2014, 11:49 PM	#21
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Timing gear knock You changed a head gasket and 1 valve, then the noise started. Did you replace anything else at that time? The new valve would have increased pressure on #3, so could that have started the piston slap? I'd probably replace the timing gear and keep this as a spare. If the new gear doesn't solve the noise, then you have a good spare gear. If the new gear solves the noise, then you can sell this mint gear on ebay.

12-23-2014, 12:52 AM	#22
PC/SR Senior Member Join Date: May 2010 Location: Santa Rosa, CA Posts: 1,278	Re: Timing gear knock Well, it's a good mystery (to us, to you an PIA). Please keep us advised. I am trying to tie it in with the change when inserting the plastic bolt (I have not heard of that before, a neat diagnostic device) and surmise that if there is a wobble, the plastic bolt might change the angle of contact with the crank gear. With .008 clearance anyway (didn't anyone check that when the engine was assembled?? But hey, it changes the cam timing) a wobble may be enough to put it over the edge and make noise. At this point I would try a new cam gear. Another long shot, as I recall, there is about .125 clearance between the gear and the cover bolt outside metal. Quite a bit, but maybe......something may be hitting. Ya got me. Last edited by PC/SR; 12-23-2014 at 01:02 AM.

12-23-2014, 03:08 AM	#23
SAJ Senior Member Join Date: Jul 2010 Location: Auckland, New Zealand Posts: 514	Re: Timing gear knock TOM, I reseated all the valves, after truing everything with my valve resurfacer. Changed no. 3 exhaust valve with no 2 because 3 was a tiny bit thinner now and no. 3 runs hotter and leaner. Put in new head gasket (BEST brand graphite). Nothing else. TBIRD, will look inside all with my scope and see what is what. Compressions are still 96 to 98 WOT hot, with 2 and 3 the 98's as they were immediately after the seizure 8000 miles ago. Knock developed 4000 miles later and I have run with it for another 4000 miles - I just checked all my records properly. It got worse after I replaced the spring and plunger with the bolt I think, removing some damping friction from the gear I guess. PC/SR I will measure the wobble with a DTI tomorrow and the deflection when I push on the gear, which is quite a lot- I certainly saw .010 deflection when levering with a screw driver when the front cover was on. The gear nut is so tight I cannot get it off with a 30 inch power bar and risk the clamp I used damaging the gear. I will have to remove the radiator and shock it off with a pneumatic rattle gun etc. There is nothing I can see that can hit inside the cover. I guess it is a worn fibre gear, maybe set up loose in the first place. Schwalms have a great reputation though. I will order 2 fibre gears , one oversize and see what happens. I think trying a metal gear might result in more noise, but I will get one as well. Thanks again SAJ in NZ Last edited by SAJ; 12-23-2014 at 03:21 AM. Reason: changed ago to later

12-23-2014, 03:41 AM	#24
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Timing gear knock If you use an impact gun to unscrew the nut, aren't you afraid of damaging the fiber teeth?

12-23-2014, 04:11 AM	#25
SAJ Senior Member Join Date: Jul 2010 Location: Auckland, New Zealand Posts: 514	Re: Timing gear knock TOM. I will put a clamp on the gear and hope it will shock off. It may well damage the fibre gear but the steel gear should be ok. Can you suggest how else to get it off? I have never used a jamming rag on fibre gears and suspect tightening them like this is why so many fail. I dont want to pull the camshaft out really and get it in a vice. I guess this fibre gear is no good anyway if worn. SAJ IN NZ Last edited by SAJ; 12-23-2014 at 04:34 AM. Reason: spelling

12-23-2014, 11:09 AM	#27
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Timing gear knock I've only changed a couple gears while the cam is still in the engine, but I have used a rag to jam the gears and not had a problem. With the cam out of the engine I will clamp it between a couple wood boards in a vice, then use the impact gun on the nut.

09-21-2016, 06:19 AM	#28
Zener424 Member Join Date: Nov 2010 Location: Staten Island, NY Posts: 77	Re: Timing gear knock For further followup on this thread, refer to post #14 in this thread: http://www.fordbarn.com/forum/showthread.php?t=204993

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