A crank sprocket (or a timing gear) is a fundamental part of the timing chain in automotive engines. Along with the cam sprocket, these automotive parts oversee guaranteeing an adequate timing between the crankshaft and the camshaft.

Learn more about the crank sprocket, the main differences between this auto part and the cam sprocket and how to choose the right components.



What does a crank sprocket do?


A crank sprocket is a part of the timing chain in engines in charge of maintaining the timing 

between the crankshaft and the camshaft. 

Combined with the cam sprocket, they represent two crucial gears that, when operating in synchronicity, are able to keep crank and sprocket shafts running. As a consequence, they are able to generate adequate combustion and thus make the engine run smoothly.


Camshaft vs. crankshaft: what’s the difference?


These two shafts are linked to the timing chain by the crank sprocket and the cam sprocket, so that their rotations are at the same pace.

However, they present some differences

  • The camshaft is located at the top of the engine, the crankshaft, at the bottom.
  • They perform different operations. On the one hand, the camshaft is in charge of opening and closing intake and exhaust valves. In order to do so, it employs cams, which are lobes that push against the valves as the motion of pistons propels them. On the other hand, the crankshaft uses the movement of pistons (to which it is coupled) to power the engine by rotating.
  • Regarding the respective sprockets, their sizes tend to vary. Typically, the crankshaft sprocket diameter will be twice bigger than the cam sprockets. This is because of the massive load on the crankshaft due to piston’s up and down movement.



Related: The different timing chain systems



How crank sprockets work


Crank sprockets are connected to crankshafts. The sprocket rotates using the movement of pistons (to which it is coupled) and, consequently, causes the shaft to rotate as well. It is able to transform linear energy into rotational energy, and consequently allows the crankshafts to power the timing chain that will later connect to the cam sprocket and camshaft. 



What causes crank sprockets to wear down?


Like a good many products in the timing, cam and crank sprockets will inevitably wear. Sprockets may lose teeth or present signs of wear because of continued use over time. This can cause timing chains to skip and, as a consequence, result in severe engine damage. 

It’s possible to notice potential crank sprocket issues: if knocking sounds are heard when the engine is running and accelerations are performed, it could be a sign of problems. A visual inspection might confirm or discard them.

Additionally, when picking the right crank sprockets, it’s important to ensure they are durable, sprockets that don’t present sharp teeth and whose keys fit perfectly.


Keep reading: The ins and outs of the timing chain: how to replace a timing chain kit


Dolz Timing Chain Kits, all components delivered in one package


The use of chain drives in today’s modern applications bears witness to the automotive industry’s continuous efforts for evolution and more precise technologies, less noise and longer transmission life being the most significant benefits of this advancement.

At Industrias Dolz, we are committed to provide high-quality automotive parts that ensure smooth-running efficient engines. As such, our timing chain kits include all components required for a professional repair, that is, all components delivered in one package: timing chain, crank sprocket, cam sprocket, tensioner, guides, oil seal, VVT…

DOLZ TIP: It is recommended to replace all timing elements in a single operation, ensuring an optimal coupling of the components and thus avoiding premature aging and possible future engine failure.

Made of high resistance steel and presenting a synergistic design with 100% tested robustness and reliability and quality OE equivalent, we guarantee the best solutions to match the automotive industry’s strive for innovation and quality.

Are you looking for the best solutions for the distribution of your vehicle?

Contact us to learn more about our full range of products!