Engines with manual transmission usually have a heavy flywheel, typically 5 to 40 kg of cast iron, with the starter ring gear shrunk onto the exterior.
This is done by heating the ring to around 200 °C to expand the ring which is then rapidly positioned onto the flywheel, often held in firmly against a spot shoulder until coolin in calm air . The interference suit between ring equipment inside dia. and flywheel, usually ranging from 0.20mm to 0.50mm, renders the starter ring firmly mounted on the flywheel.

1. Heating must be completed as uniform as feasible and never with a gas burner, as this process causes great temperature variations to the pieces.

2. the temperature ought to be 200°C. A temperature greater than 350°C will affect the apparatus tooth hardness.

3. Do not utilize compressed air or coolant to cool off the ring.

4. A precise centering and flattening of the items in the planetary gearbox flywheel is an absolutely essential condition.

5. The original center distance should be maintained.

6. Chilly power press system should be avoided due to a substantial tension caused to the hardened area.

Engines with automatic transmissions instead have a pressed metal plate with the starter ring equipment usually welded onto the outside of the plate.