Timing gear shreaded

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Cschaff63
Posts: 98
Joined: September 14th, 2017, 5:57 pm
Body Type: Dump
Model Year: 1928
Location: Pa

Timing gear shreaded

Post by Cschaff63 » January 5th, 2020, 6:54 am

Happy New year fellow AAers, Does anyone have any ideas why a fiber timing gear on a freshly rebuilt engine with less than 300 miles on it would shred the teeth off. Cruising along at 30-35 mph and makes a clunking noise and dies. Pulled the timing gear cover and gear teeth are shredded about one third of way around gear! Then, is it advisable to go to an aluminum gear at this point? Thanks in advance for any input.

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emf
Posts: 71
Joined: March 21st, 2016, 5:21 am
Body Type: Firetruck
Model Year: 1928
Location: Hudson, NY

Re: Timing gear shreaded

Post by emf » January 5th, 2020, 9:49 am

I'm going to start something here, but that may be a good thing... Fiber timing gears have been used for many many years without the 'shredding' issue. Maybe the gear that was put in your truck was a cheap one. I think the good ones with brass impregnated are good ones. I, for one, don't like the aluminum gears due to the excess noise. You can hear them from 50 feet away. Check with the rebuilder and see what he says. It could also be that your engine was out of time and it kicked back. Don't just blame the gear, maybe it was something else...

Frank

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BrianT
Posts: 248
Joined: October 25th, 2013, 8:27 am
Body Type: 82A
Model Year: 1929
Location: San Diego, California

Re: Timing gear shreaded

Post by BrianT » January 5th, 2020, 10:18 am

To shred a timing gear that quickly the most likely cause was lack of backlash between the fiber gear and the crank gear, it should be approximately 3 thousandths measured in 3 places, a common problem is that the crankshaft may have been ground of center, or the main bearings line bored out of alignment.
What ever you chose to replace it with be sure to measure the back lash and inspect the face of the camshaft for any burrs that would cause the gear to wobble, best to take back to the re builder.

Cschaff63
Posts: 98
Joined: September 14th, 2017, 5:57 pm
Body Type: Dump
Model Year: 1928
Location: Pa

Re: Timing gear shreaded

Post by Cschaff63 » January 5th, 2020, 10:38 am

emf wrote:
January 5th, 2020, 9:49 am
I'm going to start something here, but that may be a good thing... Fiber timing gears have been used for many many years without the 'shredding' issue. Maybe the gear that was put in your truck was a cheap one. I think the good ones with brass impregnated are good ones. I, for one, don't like the aluminum gears due to the excess noise. You can hear them from 50 feet away. Check with the rebuilder and see what he says. It could also be that your engine was out of time and it kicked back. Don't just blame the gear, maybe it was something else...

Frank
Thanks for the response, I agree with you. I had the time precisely set with a timing light also, has been running beautifully up to this point, for a little while I was having overheating issues but that is resolved! I do plan on asking engine builder tomorrow what to look for, AER was the engine builder. The motor is built as a touring motor with insert bearings and oversized valves with hardened seats.

David R.
Posts: 160
Joined: August 17th, 2019, 1:52 pm
Body Type: Chassis
Model Year: 1930
Location: WV

Re: Timing gear shreaded

Post by David R. » January 5th, 2020, 7:11 pm

I had a rebuilt 6 cylinder in a GM 1 ton in my fleet of bakery trucks years ago. After it stripped the third gear they sent me an aluminum one. Never stripped again but you could hear the truck coming up the alley to the plant three blocks away. Whirred like a space ship on a 1950 sci-fi movie!

Cschaff63
Posts: 98
Joined: September 14th, 2017, 5:57 pm
Body Type: Dump
Model Year: 1928
Location: Pa

Re: Timing gear shreaded

Post by Cschaff63 » January 6th, 2020, 8:11 pm

Spoke to my engine builder, he thinks it was just a bad gear, sending me a new one and all the gaskets. I hope this is the case, guess we’re gonna find out! But at least he’s standing behind his work!

David R.
Posts: 160
Joined: August 17th, 2019, 1:52 pm
Body Type: Chassis
Model Year: 1930
Location: WV

Re: Timing gear shreaded

Post by David R. » January 7th, 2020, 9:16 am

I hear a lot these days about modern replacement parts failures. Let’s hope this fixes you!

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