Engines with manual transmitting usually have much flywheel, typically 5 to 40 kg of cast iron, with the starter ring gear shrunk onto the exterior.
This is done by planetary gearbox 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 location shoulder until coolin in calm air . The interference suit between ring gear inside dia. and flywheel, usually which range from 0.20mm to 0.50mm, renders the starter ring firmly attached to the flywheel.

1. Heating must be done as uniform as possible and never with a gas burner, as this technique causes great temperature differences to the pieces.

2. the temperature should 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 down the ring.

4. A precise centering and flattening of the items in the flywheel can be an absolutely essential condition.

5. The original center distance must be maintained.

6. Cool power press system ought to be avoided due to a substantial stress triggered to the hardened region.

Engines with automated transmissions instead have a pressed steel plate with the starter ring gear usually welded onto the outside of the plate.