How to Temper a Torsion Spring

The torsion spring is a vital component for proper suspension, especially in 4-wheel drive vehicles. The spring is also commonly referred to as a torsion bar. It consists of a special steel spring which twists to regulate the front suspension. This ensures a smooth driving experience. With time, the tensile strength of the spring reduces which lowers efficiency as you drive. To correct this situation, the spring has to be tempered. It must be heated to high temperatures then cooled immediately so that the original tensile strength is regained. This is a job you can perform yourself at home and save on the costs a mechanic would charge you.

Tools and Materials Needed:

  • Jack
  • Jack stands
  • Tire iron
  • C-clamp
  • 1/2 inch ratchet and socket set
  • Torsion spring
  • Bench vise
  • 5 gallon bucket
  • Motor oil
  • Acetylene torch
  • Striker
  • Cast iron tongs
  • Safety goggles
  • Welding gloves
  • Rag

Step 1 – Prepare the Vehicle

Lift your vehicle with a jack. Use jack stands to support the 4 corners of the vehicle. Ensure that you have adequate room to work comfortably under the vehicle. Use a tire iron to remove the front wheels.

Step 2 – Remove the Torsion Spring

Check the middle of the vehicle for the torsion bar crossmember. The torsion bar keys are secured with a bolt inside the crossmember. Attach the C-clamp on top of the crossmember and secure it against the keys. Use the ratchet and socket set to unbolt the torsion bar keys from the crossmember. Loosen the C-clamp to reduce tension on the torsion bar. You can then unbolt the bar and remove it from the vehicle.

Step 3 – Preparing to Temper

Fill a 5 gallon bucket with motor oil. Put on safety goggles and welding gloves to ensure safety as you temper the spring. Place the bench vise on a stable surface. Make certain there is no wood nearby as it could catch fire. Fit one end of the spring in the vise.

Step 4 – Heat the Torsion Spring

Light the torch with the striker. Steadily apply heat to the spring. Be sure to torch all areas of the spring so that it heats up evenly. Maintain steady application of heat until the entire spring glows with a bright red color which indicates it has been heated extremely well.

Step 5 – Submerge the Torsion Spring in Oil

Firmly grip the torsion bar with a pair of cast iron tongs. Loosen the vise to allow you to remove the bar. Carefully lift the torsion and dip it into the oil until it is completely submerged. Exercise extreme care as you dip the bar so that oil doesn’t splash around. The heated oil can cause serious burns. Allow the bar to remain in the oil for about 15 minutes. Remove and wipe away excess oil with a clean rag.

Step 6 – Reinstall the Torsion Spring

Position yourself underneath the raised vehicle. Use the socket set to install the tempered torsion spring in the location from which you removed it earlier. Be sure to secure the spring firmly for proper vehicular operations.