Aluminum timing gear

metalho

metalho

Well-known member
Had to pull my timing cover to get an old two piece crankshaft pulley off. While posting pics I found out my timing gear was two piece also and should be changed out to a one piece. I looked for pics of the two piece timing gear I have now and couldnt find any info. I just cant see how this gear could come apart, but Im ordering parts from Mac's today and prob should get a one piece to be safe. My timing gear has no O-S markings on it so I guess its standard size. Should I get one size over, and should I get fiber or an aluminum gear.
 

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Hi Metalho
The two piece timing gear shown has history of hub breaking loose from fiber. Poor quality. The best is all fiber gear as this is protection if valve or cam locks up. Gear will break up instead of causing severe damage.
 
henry1930ford said:
Hi Metalho
The two piece timing gear shown has history of hub breaking loose from fiber. Poor quality. The best is all fiber gear as this is protection if valve or cam locks up. Gear will break up instead of causing severe damage.
Click to expand...
If the gear is standard size now, should I buy standard size again, or one size larger? Think its .003 O-S.
 
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BadCamGear.jpg


I agree with Vince that the cam gear looks OK in your picture, but they often get loose like in my picture, so now is the time to change it. I always use the "cloth" one as Vince mentioned, and have no problems with them.

Also pictured is the tool I made to remove the cam nut. I milled it out of a solid block of steel, then welded in a cut off 1/2" socket extension, and welded a large nut to the outside of that. This way I can use an impact wrench or breaker bar, or a large box wrench or socket. If it's really tight I can also use a combination of two together to loosen the nut.

I don't have a milling machine, so I used a milling bit in my drill press and remove a thin layer at a time until I got the proper depth. It took quite a long time, but was worth it. Of course you can buy a quality tool from the parts houses for about $20.:)
 
I think I have heard of the fiber gear and a laminated gear. What is a cloth gear?

Thanks for clarifying for me.
 
If you replace the timing gear, you should also replace the crank gear at the same time, and from the same source.
 
When I rebuilt my "primary" engine, I installed one of the composite aluminum-hub and fiber-rim timing gears. For some time I was convinced (despite repeated checking) that I had a rod knock until an older and more experienced club member took me aside and showed me the trick of reversing the timing pin, applying hand pressure while the engine idled and seeing if that took care of the knock. It did (indicating that the problem was a loose timing gear) and shortly thereafter this was verified when I took the timing gear off; the fiber outer portion was ever so loose on the aluminum hub.

Exit the composite aluminum/fiber gear, enter an all-fiber gear (albeit with the same crankshaft gear, which - as fordgarage states above - was in good condition) and everything has been fine since.

I'm not certain where the idea of an aluminum hubbed timing gear originated, but it seems to be another case of "better is the enemy of good enough," good enough being the original design.
 
Vince,

I was only advised to do that, and it seemed to be reasonable. Main reason I was given was that -- especially if you are using a bronze or aluminum timing gear -- was that the noise produced by the metal timing gears was not there when using a matched pair. I didn't think the cost of the crank gear was all that much considering, so that's what I did.

Risk in not doing so?, probably none.
 
Thank you guys for all your help. I included a cloth one piece timing gear and said cam nut socket in my Mac's order. Ill chime back in when I dont have a clue how to put it on LOL. No, Im reading up :) Thanks again.
 
I don't see what the problem is; the positioning lugs for the camshaft timing gear are offset so that pretty much takes care of one problem.

From there on out it's just a matter of getting the camshaft timing gear and the crankshaft gear lined up. Let's see; there are 50 teeth in the former and 25 teeth in the latter, so - presuming the significance of both the cam and crank gear index markings escape you - there are roughly 50 x 25 = 1250 possibilities (for the average mechanic; perhaps someone can think of additional combinations or permutations).

If you get really good and can install and uninstall a camshaft timing gear in 10 minutes (including checking out whether the engine then operates, which is a pretty fast turnaround time) it should only take 208 hours (+/-) to find the right alignment.

Heck, I've spent more time than that "easter-egging" some of my finer Model A repairs...
 
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My '28 "ate" an old Westinghouse-Micarta fibre gear last summer - the fiber gear actually came off the steel hub.

But, I do not believe this was the fault of the gear itself... when I got into the timing-case to repair things, I discovered that the cam plunger spring had several coils borken-off, and resulted in the plunger being flush at the top of its bore in the timing cover. This allowed the cam to "walk" back & forth, causing the cam gear tp slam-into the timing cover, the point of contact being the rim of the gear hitting the cover... this repeated impact causing sideways stress on the rim of the cam gear on one side only eventually loosened the fibre from the gear.

That said, with a one-piece gear, there's nothing to separate.

I replaced the the fibre gear with an aluminum one-piece from Bratton's. Left the original Ford crank gear in place.

As far as I've been able to determine, the aluminum gear is not noisy... but that's in a tired engine that's got 88,000 miles on it... and has lots of other noises going-on.

One noise that went away, was a persistent "rod knock" that turned-out to be from the cam slamming back and forth.

Just offering my recent experience.

Good luck with yours !

SC Frank
 
Special Coupe Frank said:
My '28 "ate" an old Westinghouse-Micarta fibre gear last summer - the fiber gear actually came off the steel hub.

But, I do not believe this was the fault of the gear itself... when I got into the timing-case to repair things, I discovered that the cam plunger spring had several coils borken-off, and resulted in the plunger being flush at the top of its bore in the timing cover. This allowed the cam to "walk" back & forth, causing the cam gear tp slam-into the timing cover, the point of contact being the rim of the gear hitting the cover... this repeated impact causing sideways stress on the rim of the cam gear on one side only eventually loosened the fibre from the gear.

That said, with a one-piece gear, there's nothing to separate.

I didnt even have a

I replaced the the fibre gear with an aluminum one-piece from Bratton's. Left the original Ford crank gear in place.

As far as I've been able to determine, the aluminum gear is not noisy... but that's in a tired engine that's got 88,000 miles on it... and has lots of other noises going-on.

One noise that went away, was a persistent "rod knock" that turned-out to be from the cam slamming back and forth.

Just offering my recent experience.

Good luck with yours !

SC Frank
Click to expand...

I didnt even have a cam plunger when I took the timing cover off. Might be in the oil pan from when the two piece cam gear was instaled 25 years ago. Ill find out when I drop the pan for the new rope seal and pan gasket.
 
I have read in more than one place that it was not unusual for less-than-knowledgeable mechanics to leave the plunger and spring assembly out. Perhaps they were so frustrated by the process of getting the cam gear nut undone and retightened that they just buttoned it up as-is, that is, without the plunger and spring.

Regardless, there is a Tiny Tip out there (I'll have to track it down and provide the citation) whereby some enterprising Model A mechanic removed the cam plunger and spring, drilled out the bottom of the plunger boss in the front timing gear cover, and threaded it for whatever size bolt - equipped with a jam nut - would fit. Any end play in the camshaft was taken out by threading the bolt - which had its end faced to provide a flat bearing surface to bear against the end of the camshaft - in an appropriate amount and tightening the jam nut.

One should never underestimate the ingenuity of the average mechanic nor the lengths to which some will go in order to work around an otherwise serviceable - or repairable - component...
 
Follow-up on the possible correlation of failed fibre gears to bad / missing cam thrust plungers.

I am in the process if disassembling a spare engine, May 1929, to see what it needs before it goes back in a car.

I had it flipped upside-down this evening, to pull the pan and check the bottom-end.

This exposed the bottom-side of the timing gears... I decided to grab the rim of the cam gear and see if I could work the cam back and forth, along the camshaft axis, and sure enough, I could. When I would pull the cam gear forward, it would just sit there; when I would push it back towards the rear of the engine, I looked in the timing case with a light, and did not see any plunger bearing against the cam-shaft.

Each time the cam "bottomed" in either direction, there was a hollow "knock", sounding much like a bad rod bearing.

The last time I moved the cam by the cam gear, I noticed the cam gear wobbling... a closer look showed the fibre was wobbling on the hub... heading to the same end as the Micarta gear in my coupe.

I have a suspicion that a failed or missing thrust plunger is one of the major causes of failure of original / old fibre gear separation from the hub.

Will follow-up when I open the timing case.

SC Frank
 
Tip: The oil pan has a removable "windage tray" or often called dipper tray which allows the connecting rod lower ends to get oil from the grooves in the tray.

To remove the tray, after you drain as much oil from the pan as possible, take the tray and holding it upside down,drop it onto a level lawn and the impact will knock the tray out of the pan. Do not attempt to pry it out as it can be easily bent. Now you can clean all the gunk from the bottom of the pan. I found an engine that had 2 inches of mud like sludge but still ran somehow.

Good luck, Mike
 
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