4.9 Plastic Timing Gears

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Sep 29, 2015 | 11:24 PM

carmexjoe

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4.9 Plastic Timing Gears

I apologize in advance if this has been covered elsewhere but I haven't been able to find any information on it. When did ford start putting plastic timing gears on the 4.9? I currently bomb around in a lovable yet crusty 81 F-100 and am wondering if I should pick up a set of steel gears as a preventative measure.

Sep 29, 2015 | 11:29 PM

85e150

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Probably in 1965.

Do you notice any plastic debris in the oil when you change it?

Any strange noises from the timing set area?

Sep 29, 2015 | 11:33 PM

carmexjoe

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No plastic debris and it makes the same squeaks, grunts and kerchugging sounds that its always made.

Sep 29, 2015 | 11:44 PM

85e150

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Just run it..... Serving suggestion.

Sep 30, 2015 | 07:25 AM

Franklin2

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From: Virginia

They do wear out once in awhile. I have never worked on a six, but I seem to remember one of the gears is phenolic, not plastic. The v8's had the plastic coated aluminum gears that likes to break off and get in the oil pump suction screen.

Phenolic is layers of some sort of fabric soaked in a resin and then compressed. It's pretty good stuff, but of course like anything it will wear over time.

Sep 30, 2015 | 09:48 AM

1986F150six

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From: Sheffield, AL

My 1986 4.9L has 187,350 miles with the original phenolic gear with no problems.

My son's 1984 with same power train has over 237,000 miles and is still original.