I am rebuilding an 1912 engine and there is a good Fiber timing gear in it, CAN I use that Gear again or replace that for a All. or Bronze
thanks for your answer Toon

I think you are mistaken when you say there is a good fiber timing gear. You should replace it with any other type of timing gear while the engine is apart. The fiber gears fall apart unexpectedly.

Glad you asked the question first! Please remove the fibre gear and replace it with steel, bronze or aluminium. I am currently rebuilding my '26 Fordor engine which has a broken crankshaft which I am sure is directly related to the failed fibre timing gear. I know of many others that have suffered the same fate. I am only disappointed that I didnt change mine out earlier.
Warwick.

When my fiber gear failed, I replaced it with an aluminum gear!

The nylon ones are holding up well, and are quieter than the metal ones.

This is what you are aiming for with fiber gears:

I think it is important to note that there are two types of fiber timing gears: a woven fiber gear and a pressed mesh gear. The woven fiber gears are quite strong, quiet and very reliable. One thing I have found with some aluminum gears is that the timing marks are mismarked and you need to check your valve timing before you start the engine. Hope this helps. Russ Furstnow

Some years ago I spent an extra week on a trip, stuck in a Trinidad motel while I waited for new valves and other repairs to a Suburban. Why? Because the nylon timing gear failed. I would go with what Ford used originally. Wasn't that steel? After all, we're not dealing with Hitler's Mercedes here. It's a Model T. I'd rather have a little noise than engine failure out in the sticks.

Steve:

I believe the nylon gear is a recent item, out about 2 years.

Maybe the manufacturer or vendors can comment on when the gear made it's debut.

Bob, it may be new for the T but GM was putting them in Chebbies thirty years ago, hence my unfortunate experience.

Performance T Parts has them in their VF ad in the Jan/Feb 2005 issue. That's 4-1/2 years ago by my count, which is plenty of time to establish a track record for them. (I put 3,500 miles on one last year alone.) It's difficult for me to believe that if there had been faiures of this part, the irate car owners wouldn't have let us know about it here on the forum.

All my Ts are non genertor cars. They all have fibre gears. For my 10, the only oversize gear I could find was a fibre gear sold by Synders. I have run many thousands of miles on these cars without a hitch.
I would be leary about installing a fibre gear in a car with a generator, but don't have a problem using them in cars without one.

The car that fiber gear came from was a generator engine.

Thank you all for your input about the Fiber Timing gear .
He is hanging on the wall now !!!!
greetings Toon

I don't know when they (nylon) first came out, but I will tell you that as long as I can keep buying them - that's what's going in our engines. It's all we sell now too. Standard or "altered" timing is available through us.

I remember many many years ago on my '67 Corvette 427, having to change the cam gear on New Year's day in Northern IL with no garage - did it in the driveway with 15 minutes of work and then 15 minutes to warm up. It was below zero. The 'vette was my daily driver so had no choice - it had jumped time - YEP - nylon gear. That 'vette was without a doubt one of the most unreliable cars I ever owned but what's worse is that it always found a great spot to dump me in. Get 50 miles from nowhere and it was sure to have something go wrong with it. Rear wheel bearings were notorious and they required a complete tear down of just about everything. Even putting a battery in it took an act of Congress - BUT - it could NOT be beat for quail hunting - (2 legged type with pretty feathers). That was important then - doesn't seem as important now - not sure - can't remember.

When i traded for my old Chevy wagon it had 99,000 miles on it.The man told me to change out that plastic timeing gear.Well once the car got 286,000 miles on it I needed a water pump.I fiqured I was close enough to the timeing gear to go ahead and swap it out just for the heck of it.
I cut myself on the teeth on that timeing gear.The nylon was GONE and it had been running on the aluminum that was under the teeth.I had a picture somewhere.But I tell ye,it was wore slap out.Car run better once I swapped that stuff out.
A couple days before i started the parts swap I had drove the car on I40 at 75 mph for around 40 miles between towns and a couple 100 miles on secondary roads.it coulda went anytime.I was just plain lucky.
But that experiance taught me to use steel timeing gears.I used a nos 1 in the engine in my little T pickup.So what if it makes noise.
John I woulda never thought a Vet would be so unreliable for what they cost.The only thing is if you still had that car,you could probably get your asking price fairly easy nowadays.

I'm not sure the comparison of GM's early gears is an apples to apples comparison to the solid nylon gear being sold today. The GM gear was a designed failure (steel gear with plastic teeth). Nylon compnents are common in aerospace products due to weight savings.

In the GM example you don't have a meshed gear running together but rather a chain (subject to growth from stretch). I would also assume that the effort to overcome the valve train in a SB Chevy is considerable when compared to the T's 26 lb valve spring pressure. I would also venture to guess there is less effort required to turn the T generator that in the case of the SB Chevy valve train.

The nylon T gear doesn't scare me a bit.

I ran a nylon gear on the O2O trip the engine had little over 4000 miles on it when the crank broke but the gear was fine and with a generator. Quiet too!

I've found that some torn up fiber gears I've seen seem to have been caused by bent generator shafts and pitted and worn generator gears.

I don't own any generator equipped Model Ts. My new fiber timing gear stripped in about 400 miles. Replaced it with an aluminum gear and have run 1500 miles no problems.

I would add to Adam's comments and think the role of a generator upon failed fiber timing gears is overlooked.
I have seen several situations where upon installing the generator on an engine with a metal timing gear there is significant gear noise. We found in these cases there was no gear lash between the generator drive gear and cam gear. You can feel lash by touching the generator drive gear inside the oil cover. In one case we found the gasket between the generator side mount and engine block had been left out and only sealant was used, in the other case to obtain necessary gear lash we had to add an additional gasket to obtain some gear lash. Both these cases would have led to excessive metal gear wear.
If these situations existed with a fiber/nylon gear I can see where it could cause premature gear failure.
One may not intuitively think of it when installing a generator, but I suggest you ensure there is sufficient gear lash between the generator drive gear and cam gear.
Ron the Coilman

Ron- I would like to add to your comments that it is important to make sure the generator bracket is parallel to the cam. Cross bearing of the gear teeth can also reduce or eliminate backlash. When installing the generator bracket it is very important to make sure that the front surface is parallel to the front of the block.
Dan

I learn so much from reading this Forum and realise thing I did not thought about when I did various jobs.
As can be read above I swapped a crushed fiber gear with an original steel gear and my car is not noisy. But all seals where in place and also when I overhauled the engine last winter, they where replaced with new seals + sealant.
My engine have no noisy timing gear.

Actually, a modern fiber timing gear is quite a strong part. If you are nervous about potential failure, a coating of modified bitumen roofing tar over the outer edge of the gear will ensure many miles of trouble free operation.

I have heard this argument for years. The fiber timing gears introduced in the twenties were used in lots of cars costing far more than our Ts. This type of fiber gear was used for many years for dependable transportation.
I try to find the old NOS variety at swap meets ect. I have never had a failure in fifty years using these old ones although failure of almost any part may be lerking around the corner, it is part of the hobby.


I have talked with several who have had fiber gear failures but I beleive all gears were the new repo collector car type units.

Reid Welch studied them and came to the same conclusion, Warren. The old ones were made of different material. Maybe they were made from hemp?

That's a reference to the prior thread about hemp being used in the first Model T.

rdr

Re-using an old worn out crankshaft timing gear can also wipe out a fibre timing gear real quick. Royce, did you have a new crank gear installed before you wiped out your fibre gear?