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Fordfan29 · 09-15-2019, 07:41 PM

About 10,000 miles ago I changed my bronze cam gear (worn just beyond spec's), replacing it with another bronze gear & a matched crank gear at the same time. After about 5000 miles it developed a knock at about 43 mph in high & a knock at about 53 in high & overdrive that has continued to get worse. Either side of those speeds the engine ran fine but recently began to knock occassionally at idle. I've opened up the engine & checked the distributor drive gear and adjusted the valves since they were needed. Nothing changed as far as the knock. Checking the timing gears I found the bronze gear worn beyond the 0.003-0.005" specified (0.010). I had installed the gears with an original cam thrust spring and I shimmed it to the 35 lbs. at the assembled height. My question is how to control the cam thrust because I think the bronze gear wear is from the cam moving forward & back.
I tested a new thrust spring with the same shims & found it to be 45-47 lbs. at the same installed height. Is this too much pressure on the cam? I have driven my car a bit over 80,000 miles and moved to metal gears for dependability years ago.
What life should I be expecting from bronze or aluminum gears?

I'm open to any suggestions.

09-15-2019, 07:41 PM	#1
Fordfan29 Member Join Date: Mar 2017 Posts: 41	Timing gear/cam noise? About 10,000 miles ago I changed my bronze cam gear (worn just beyond spec's), replacing it with another bronze gear & a matched crank gear at the same time. After about 5000 miles it developed a knock at about 43 mph in high & a knock at about 53 in high & overdrive that has continued to get worse. Either side of those speeds the engine ran fine but recently began to knock occassionally at idle. I've opened up the engine & checked the distributor drive gear and adjusted the valves since they were needed. Nothing changed as far as the knock. Checking the timing gears I found the bronze gear worn beyond the 0.003-0.005" specified (0.010). I had installed the gears with an original cam thrust spring and I shimmed it to the 35 lbs. at the assembled height. My question is how to control the cam thrust because I think the bronze gear wear is from the cam moving forward & back. I tested a new thrust spring with the same shims & found it to be 45-47 lbs. at the same installed height. Is this too much pressure on the cam? I have driven my car a bit over 80,000 miles and moved to metal gears for dependability years ago. What life should I be expecting from bronze or aluminum gears? I'm open to any suggestions.