the surface burner knobs feel loose and wobbly, they don't have a firm click when you turn them.

Diagnosis

The wobbly sensation and loss of "click" in the GE JGBS66REKSS knobs are typically caused by the failure of the internal D-shaped plastic sleeve or the degradation of the valve stem's detent spring. The knobs on this specific model are not threaded; they rely on a friction-fit plastic insert that grips the metal splined valve stem. Over time, heat from the burners causes this plastic to warp or crack, creating a gap between the knob and the stem. When this happens, the knob rotates independently of the stem for several degrees before catching, resulting in a "loose" feel. Furthermore, the "click" is produced by a small spring-loaded detent ball located inside the gas valve assembly. If the knob's internal sleeve is worn, it cannot apply the necessary pressure against the stem to trigger that tactile click. You can confirm the root cause by removing the knob and attempting to turn the metal stem with a pair of pliers (carefully). If the stem itself clicks firmly into position, the problem is exclusively with the knob's internal plastic housing. If the stem rotates smoothly with no resistance, the internal valve spring has failed or become jammed with grease and debris.

How to Fix It

If the issue is caused by a worn knob insert, follow these steps to replace the hardware and restore the tactile response:

1. Clear the cooktop of all pots and pans. Gently pull the affected knob straight outward. Do not rock it side-to-side, as this can bend the valve stem.
2. Inspect the interior of the knob. Look for a white or grey plastic D-shaped insert. If this insert is loose, cracked, or missing, the knob is stripped and must be replaced.
3. Check the metal valve stem for any buildup of solidified cooking grease or spilled liquids. Use a cotton swab dipped in isopropyl alcohol to clean the splines of the stem thoroughly.
4. Acquire the exact replacement knob for the JGBS66REKSS model. Ensure the replacement is the OEM part, as generic versions often have slightly wider internal diameters that lead to immediate wobbling.
5. Align the D-shaped flat side of the knob insert with the flat side of the valve stem.
6. Push the knob firmly onto the stem until it sits flush against the control panel bezel. You should feel a distinct "snap" as the plastic grips the metal.
7. Test the rotation. Turn the knob through its full range of motion to ensure the "click" is restored and there is no lateral play.

If That Didn't Work

• Replace the Gas Valve Assembly: If the metal stem rotates without any clicking resistance even when the knob is removed, the internal detent spring has collapsed. This requires replacing the entire valve manifold for that specific burner. This is a complex repair involving the disconnection of the gas line and the removal of the cooktop surface.
• Shim the Knob: For a temporary fix if you cannot source a part immediately, wrap a single layer of PTFE (plumber's) tape or a tiny piece of thin plastic shim around the metal stem before pushing the knob back on. This tightens the tolerances and can restore some of the stability.
• Deep Clean the Valve Stem: Use a needle-nose tool to remove any carbonized food debris trapped in the grooves of the splined stem. If debris is lodged there, it prevents the knob from seating fully, which creates the illusion of a loose knob.
• Check the Bezel Clearance: Inspect the control panel bezel. If the bezel is slightly bent or warped, it may be pushing the knob outward, preventing it from seating deeply on the stem. Gently nudge the bezel back into alignment using a flat-head screwdriver.

Heads Up

• Avoid using heavy-duty degreasers or caustic chemicals directly on the knobs, as these can degrade the plastic inserts and accelerate the "wobble" effect.
• Never force a knob onto the stem if you feel resistance; you may bend the valve stem, which will lead to gas leaks or an inability to turn the burner off.
• When cleaning the cooktop, avoid spraying liquid cleaners directly into the knob stems, as moisture can seep into the valve assembly and cause the detent spring to rust.
• Periodically check that all knobs are seated firmly; a loose knob can lead to "ghost" settings where the burner is slightly on even though the knob appears to be in the off position.