Model A & B

Ford Garage

Camshaft Timing Gears

There have been a variety of engine camshaft gear designs and materials used over the years for the Model A and B. Shown below are a series of pics showing some of the variations.

The camshaft gear has 50 helical cut teeth, and rotates at half the engine speed. The crankshaft gear has 25 helical cut teeth and rotates at engine speed.

The original Ford engine camshaft gear was a phenolic construction made up of laminations of fabric. These are often found with Ford script and the logos or identification of manufacturing companies such as Formica, Celoron, Micarta, and others. The main feature of these gears is quiet running when used with a good crankshaft gear.

These genuine Ford gears were produced both with and without the aluminum hub center shown above.

The fabric and phenolic gears having the aluminum hub centers often fail at the interface of the gear to the hub, loosening up and producing a knocking noise when running. In the extreme case, the fabric gear can separate from the metal hub.

Pictured above is a replacement crankshaft gear. The original crankshaft gears were similarly made and worked well if not corroded. When corroded, any crankshaft gear will have the tendency to prematurely wear out the camshaft gear.

Thus in later years it also became popular to use machined cast and billet aluminum camshaft timing gears because they were deemed more robust than the fabric gears. The metal camshaft gears are also credited with being noisier than original fabric gears.

Shown above is an Alcoa aluminum camshaft gear. Below is a no-brand aluminum gear from the 1970s.

Shown above is an original Ford machined die-cast aluminum camshaft gear which was used in the German G28T engines. This style of gear was also produced in Canada at some point.

For the ultimate gear-head, Bill Stipe produces this steel hub and billet aluminum camshaft gear, shown above, which is adjustable in order to vary the cam and valve timing relative to crankshaft and piston position. The two-piece gear has a built-in vernier to dial in the exact angle changes desired.
Stipe Machine & Specialty Motor Cams web site.

There have also been a couple of sources of machined bronze gears in recent years.
Shown above is a billet bronze gear made by Ron Kelley.

In addition, Dan McEachern makes both machined cast bronze and cast aluminum camshaft timing gears, as well as steel crankshaft gears.

For top quality matched metal gears, contact:
Dan McEachern
920 Pearl St
Alameda, California 94501
(510) 532-8228 work
(510) 769-7524 cell

Shown above and below is an example of a vintage steel camshaft gear which came out of a Riley racing engine.

Shown below is an example of another iron/steel camshaft gear. This NOS one was for Gleaner Baldwin combine engines for driving the side-mounted engine governor.

It is similar in appearance to a Model T gear, but with helical teeth and in Model A dimensions.

The restoration market has also been fraught with poor quality, inexpensive macerated fiber gears for many years. The macerated fiber style gears do not have any fabric construction, only short fibers.

Though available in all the restoration parts catalogs, they are the worst choice for a gear due to their lack of strength and their propensity to separate into fiber fluff and plug the oil pump and main bearing oil feed tubes.

The internet message boards and club magazines include numerous reports and photos of self destructive failures of macerated gears.

The final pic above shows the best replacement fabric reinforced phenolic timing gear currently available. This is a good quality gear. It is made from resinated laminations of textile fabric, similar to the originals.

Bratton's is the source for this quality USA made fabric gear. This is not the macerated fiber gear sold by many other suppliers.

Check out this great YouTube video from Ray White showing how to replace the gear!

More related information on Ford Garage:

  1. For more Model A & B related information, use the Site Search box at the top or bottom of this page.
  2. Model A & B Camshaft to Crankshaft Gear Alignment
  3. Model A & B Camshaft to Crankshaft Positioning
  4. Model A & B Camshaft Gear Front Timing Cover Differences
  5. Model A & B Original 5-Z-1832 Cam Gear Wrench
  6. Model A & B Camshaft Thrust Plungers
  7. Model A & B Original Ford Camshaft Details
  8. Model A & B Bill Stipe Machine Shop
  9. Bill Stipe's Specialty Motor Cams Web Site

January 2008