Shredded the timing gear...but how?

[H. L. Chauvin]

Not everyone would take the time to share such a sad experience of a Model A part failure.

Thanks for sharing such a hands on learning experience.

FWIW, it is not just Model A "fiber" timing gears -- I was left stranded after about 3,000 miles with a broken fiber timing gear on a new General Motors car in the mid 1970's -- old mechanics can relate hundreds of experiences with changing many fiber timing gears years ago -- Bratton's in his above ad, (through years of experience), even suggest carrying a spare "fiber" timing gear.

Also, if one researches a few years back, one can find that there were many Model A Forum heretics professing that metal timing gears were always far too noisy until one new gallant Forum member condemned this heresy & introduced his actual experiences with Mr. Dan McEachern's quiet metal timing gears.

Looks like many prefer to save the $12.00 on buying a new fiber gear so they can buy a few "double" Whoppers at their next meals ...... then after their fiber gear breaks, they wind up eating Vienna Sausage & crackers for (2) months to pay for a new $60.00 metal gear.

Just hope the picture you shared helps one in choosing their next "long lasting" Model A timing gear.

[tbirdtbird]

"that is a choice those who use him must accept"

could not an owner spec out what gear he wanted?

[a-bone newby]

my a did the same thing but it was from a pitted crank gear so I replaced both with a aluminum cam gear don't understand a fiber gear looks cheesy to me

[rocket1]

hey why can't they get these motors right,thats like the third one on the barn recently,poor parts, poor workmanship? what is the solution?

[Bob Bidonde]

I would think that the rebuilder would want to retrieve that broken timing gear he has especially made for his business, and find out why it failed. It looks to me as if the gear material may be the cause.

Also, the laminated timing gear sold by Bratton's is far superior to those composite fiber types that preceded the laminated gear. Failures of the laminated gear are uncommon, so why an especially made non-metallic gear?

[Tom Wesenberg]

Sponsored Links (Register now to hide all advertisements)

I agree with Bob. I use a good fiber gear in a stock engine and have no problems. That gear material looks like the wood boards that are made from compressed sawdust.

I also agree with Mike that the gear sure looks dry. I wonder if the oiling system was modified in any way?

[hardtimes]

Originally Posted by fivefix

That's a great question. They only milled .010 so I sure wouldn't think they would hit. Heard AER is now milling all Snyder's 6.0 heads before assembly. Here are pictures of 1 & 2 and 3 & 4 when I pulled the head last week.

Could you say ...what is the shiny marked head on valve #1 cyl ? Did it hit something/bent ?
Also, did you wipe all the lube from the gear and areas , shown in the two destroyed cam gear areas ? It looks REALLY dry if not wiped !

Personally, for the extra FEW dollars that an aluminum gear cost, over any fiber gear, AND all the heart aches and labor/cost of repairs, I can not understand why anyone these days would not install the aluminum cam gear. Especially rebuilders, who put their reputation and business to test with each product sold !!

Wow, I feel for you, as the cost of an A/B rebuilt long block is not cheap outlay for the average Model A owner ! When considering pulling an engine back out, disassembly and shipping/transportation costs plus owner stress/dissatisfaction, etc....all add up to a VERY expensive fiber gear.

Appreciate your sharing with us and we will look forward to what you find out about this situation.

[mshmodela]

Sorry to read of your timing gear failure.. My ignorance that non metal timing gears even existed. Best wishes and thanks for sharing.

[ora masters]

Why would you pull motor to change a timeing gear

[Tom Wesenberg]

Originally Posted by ora masters

Why would you pull motor to change a timeing gear

I was debating what I would do if it was my engine. Since it's winter and the car is done for the season, if I had a heated garage, I'd probably pull the engine. Otherwise, you can just pull the pan in place and the timing cover and gear, and hope everything else is OK.

[hardtimes]

Originally Posted by ora masters

Why would you pull motor to change a timeing gear

Hey ora,
Well, in addition to what Tom says, I'd pull engine due to concern about where all that cam gear debris possibly went in engine ! In other words, what is maybe plugged up , i.e.-oil pump, oil passages, etc.

[Purdy Swoft]

It would be much easier to work on with the engine out and on an engine stand. Usually when the oil pan has to be removed and replaced I'll just go ahead and remove the engine. I don't much like laying under one with oil dripping an trying to do a good job that won't leak when I replace the oil pan .

[H. L. Chauvin]

One or two broken fiber timing gear teeth is one thing; but the shredding one sees in the photo appears to be a different matter.

Possible scenario .............. not even considering Murphy's Law:

1. Timing gear first started to shed fiber.
2. Fiber fell in oil pan.
3. Oil pump screen kept out large broken teeth particles, & pumped shredded small particles.
4. Small fibers possibly got into the valve chamber & slid towards the drain holes.
5. Drain holes to mains may have been partially plugged.
6. Oil holes on tops of connecting rods may have picked up small fibers.
7. Add a little sludge to the small timing gear fibers to create plaque & minor artery blockage & the Babbitt may forced to start a reduced-oil & low-cholesterol diet where a cardiologist's Statin drugs may not work in a Model A.

Just maybe a few things one may want to verify "inside" to be on the safe side.

[Great Lakes Greg]

Wow, all this gloom and doom makes me want to pull my engine instead of just pulling the pan. I guess it's going to be a lot of rolling around on the cold floor either way.
It just seems like a lot of work with the headlights, bar, and radiator coming off. You retired guys probably have nothing better to do, but I still have to work for a living.

[George Miller]

I see you are using over size intake valves. Are you also using stronger valve springs to stop valve float. If so that would along with the touring cam put more load on the timing gear.

[pat in Santa Cruz]

my buddy used one of those in a AER engine that did the same thing. Rich gave him the option of the cheap fiber, laminated or metal. Don thought since the engine was for his AA, and would have only a few miles in its life, he would go with the cheaper gear. Then he had a problem with his car, and substituted the AA engine in so he could go on a long tour. The gear failed with less than 500 miles. It looked chewed up exactly like the one pictured in the first post (except for the color, which is camera related)

I have been hearing bad things about the cheap fiber gears for many, many years. Its the classic "get what you pay for" situation. I have had good luck with laminated gears, but what I run in my touring car is a set of McEachern's matched metal gears. Its a quiet and worry free set; well worth the expense..

[tbirdtbird]

Pat, this stripped out fiber gear issue re-surfaces on a regular basis. The suggestion of using metal gears is typically ignored. Why do you suppose that is?

[Mike V. Florida]

Originally Posted by tbirdtbird

Pat, this stripped out fiber gear issue re-surfaces on a regular basis. The suggestion of using metal gears is typically ignored. Why do you suppose that is?

I think it's due to the rational that the teeth will strip when there is a problem. Although I have to admit I have never read here about a catastrophic failure due to the teeth of a metal gear not stripping with a problem in the drive train. Has anyone heard of or has pics of what happens when the valves stop and the gears do not along with causes?

[tbirdtbird]

It is hard to imagine the valve gear in a running engine seizing.

If a car sits for years and the valves seize, then no part of the engine will rotate (metal or fiber). It will be obvious that something is wrong but no damage will occur.

After the Model A years there were many engines with timing chains and metal gears. The same concept would apply I would think.

[Y-Blockhead]

Originally Posted by tbirdtbird

After the Model A years there were many engines with timing chains and metal gears. The same concept would apply I would think.

I've seen plenty of bent push rods in OHV engines with stuck valves, especially with todays gas gumming up the works.