Laminated Timing Gear

[WHN]

Originally Posted by PH Billet

My understanding is that the fibre gear was a “fuse” for the motor put in as a weak point to prevent catastrophic damage to the engine if a turning shaft should seize?

This has been my understanding for years. It is the same as a sheer pin on a propeller. Or the key on your rear wheels. Something to give first before everything blows up.

This is why I have always used the fiber gear and not the aluminum one.

Enjoy.

[katy]

Originally Posted by PH Billet

My understanding is that the fibre gear was a “fuse” for the motor put in as a weak point to prevent catastrophic damage to the engine if a turning shaft should seize?

Sounds like an "old wive's tale" to me.

[john in illinois]

There are 2 kinds of fiber gears. Laminated and non laminated (I think called composit) The laminated gears are what you want. You can see the fabric threads in the laminated ones.

I personally use aluminum or bronze

John

[1955cj5]

Originally Posted by john in illinois

There are 2 kinds of fiber gears. Laminated and non laminated (I think called composit) The laminated gears are what you want. You can see the fabric threads in the laminated ones.

I personally use aluminum or bronze

John

From this it seems the macerated gears are to be avoided.


https://www.fordgarage.com/pages/camshaftgears.htm


This is what is recommended unless you prefer aluminum or bronze.


https://www.brattons.com/LAMINATED-S...ductinfo/8750/


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[john charlton]

The original fitment was the "Celeron" gear . This had an aluminium centre which was bonded and keyed to the fibre gear . This was a durable long lasting gear but would become very noisy when the centre became loose . The engine would still run but with a loud rattle/knock . The same gear was fitted to the AF small ( 3" ) bore engine . This engine produces 28 BHP @ 2600 RPM and are notorious for "eating" their timing wheel . This indicates that the higher revolutions during normal driving was a factor in timing gear failure . Normally every tooth worn out not a group of damaged teeth and the rest OK .

John in sunny morning Suffolk County England .

[john charlton]

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The timing gear failure in the AF engine sometimes caused bearing damage as the the oil pump pick up screen became blocked . I have had oil pump screens where they look like they are covered in brown felt from the fretted gear . If you have lost just a few complete teeth maybe no need to pull the pan but if all teeth worn out before failure then drop the pan and clean the screen .

John in same place same weather .

[updraught]

According to this Ford literature the timing gear is bakalized fabric instead of metal for quietness. And the engine is practically vibrationless.
https://i.ebayimg.com/images/g/FCAAA...49/s-l1600.jpg

[jack backer]

There is inherent chatter in a 4 cylinder 4 stroke with a gear driven cam shaft.Ford used a fiber gear to quiet the chatter. It is not a ‘fuse’ it’s a bandaid to provide for customer satisfaction based on noise.

Fiber shed from the gear can cling to the oil pickup screen resulting in the oil pump starving for oil.

[Kenjt]

I can at last report that I have my car back. Unfortunately, the mechanic delivered it a day before I went on a trip. One month later, with beautiful weather, I took the car out for a drive, after charging the battery overnight. It started right up and drove great! My only problem now is that I haven't driven an A for almost 25 years. I'll have to drive it around the neighborhood for a while before I take it out in traffic. One thing I must say is that I'm having trouble getting in and out of it (6' 2" and about 215 pounds) even with the top down. My last car was a 31 4 door phaeton, that I had no problem getting in and out of (top up or down). Could the doors on a roadster be smaller?

[Joe K]

Your Model A friend and mine Vince Falter has discussed the timing gear variants.

https://www.fordgarage.com/pages/camshaftgears.htm

Vince discusses the originals which were made in two variants (aluminum center and solid fiber) The solid fiber is the more successful.

He discusses aluminum and bronze replacements with high marks for each except for the noise.

He discusses a modern production gear which is made more like the original Ford "successful" gears and speaks highly of these too.

And a reference to a bonus Youtube video on how to change the gear.

Joe K

[nkaminar]

I think the doors get smaller the older you get. I am having problems getting in and out of my 30 Fordor whereas when I was 16, no prob, even with a coupe. I have a movie of my grandfather getting in the passenger side of my coupe when I was 16 and he was having problems.

Regarding the timing gear, there is a good article on them in the latest issue of The Restorer, the magazine of the Model A Ford Club of America. (Volume 67, Issue 2, July/August 2022, page 17) By John Trumbo.

Regarding the timing gear nut, there is a nut available that can be tightened and loosened with a normal socket wrench. See https://www.snydersantiqueauto.com/p...8740&cat=41685

[Kenjt]

My mechanic showed me the old timing gear and it was very clearly damaged. He did replace it with the fiber type. So far no issues.

[1crosscut]

Maybe change the way you are getting in.
Sit in the seat with both legs outside on the running board and then bring each leg in.

Roadsters are tight.

[updraught]

Tourer or 4 door pheaton doors and roadster doors should be the same, well for 30-31 anyway. 28-29 may be smaller. Our doors for 1930 are wood framed.

[Kenjt]

Could it simply be that the seat in a roadster is closer to the steering wheel than in a phaeton? I know the roadster seat is not really adjustable and have no recollection if the phaeton front seat is.

[Orlfire53]

I’ve been trying to replace my timing gear all day with no luck. Going to aluminum, got offset tabs lined up, timing marks line up but or some reason I cannot get the new gear all the way on the cam shaft. Does it take some “gentle persuasion “ to go on the tabs or should it just slide on? Don’t want to bust the gear by forcing it. Any suggestions would be greatly appreciated.

[WHN]

I’ve replaced a number over the years. They all just slid on without much force.

Never installed an aluminum one. Just fiber.

Good luck.

[katy]

Originally Posted by Orlfire53

I’ve been trying to replace my timing gear all day with no luck. Going to aluminum, got offset tabs lined up, timing marks line up but or some reason I cannot get the new gear all the way on the cam shaft. Does it take some “gentle persuasion “ to go on the tabs or should it just slide on? Don’t want to bust the gear by forcing it. Any suggestions would be greatly appreciated.

It should just slip on, you could try measuring the hub on the camshaft and the bore of the timing gear to verify fit. Also compare w/the old gear.
I put an aluminum one on my '31 a few years ago w/out any problems.

[Herb Concord Ca]

When I installed mine, the two pins in the camshaft didn't line up with the holes in the timing gear. Had to rotate the camshaft with a strap wrench to get them lined up.

[john in illinois]

Yes the gear only goes on one way. Do not try to force it or it will damage the offset holes.

John