Tools Required

General purpose thread repair kits. These kits are available commercially.

Caution: Wear safety glasses in order to avoid eye damage.

Important: Refer to the thread repair kit manufacturer's instructions regarding the size of the drill and tap to use.

Avoid any buildup of chips. Back out the tap every few turns and remove the chips.



1. Determine the size, the pitch, and the depth of the damaged thread. If necessary, adjust the stop collars on the cutting tool and tap to the required depth.
2. Drill out the damaged threads. Clean out any chips.
3. Lubricate the tap with light engine oil. Tap the hole. Clean the threads.



4. Thread the thread insert onto the mandrel of the installer. Engage the tang of the insert onto the end of the mandrel.

Important: The insert should be flush to one turn below the surface.

5. Lubricate the insert with light engine oil (except when installing in aluminum) and install the insert.
6. If the tang of the insert does not break off when backing out the installer, break the tang off with a drift.

Caution: Protect yourself by wearing safety glasses, earplugs, a respirator, gloves, and safety shoes while performing work on the vehicle.

The following assembly information is used to assemble the Heli-Coil® inserts into aluminum components. Steel components can also have Heli-Coil® inserts if there is enough material thickness.

Notice: The drilling depths are maximum and should not be increased. Spark plug thread repairs do not require drilling. The piloted reamer part #5515-14 removes the damaged thread and cuts a new thread simultaneously.

Drill out the damaged threads using the drill specified in the table to a sufficient depth specified in the table.

Select proper tap specified in table and tap the hole to a sufficient depth that will accommodate the insert required.

Clean counterbore, walls, and seat. Engage pilot threads and rotate tap until depth collar bottoms out. Remove tap and clear chips from hole.

After tap has been removed use compressed air to blow chips out of hole. Take care not to blow chips into engine.

M6

Remove mandrel from prewinder, and place insert onto threaded end of mandrel. Place mandrel in prewinder threaded end down and turn into prewinder two turns. Position squarely over hole and rotate mandrel clockwise until upper coil is 1/4 - 1/2 turn below top surface.

M8-M12

Select the proper size Heli-Coil® insert from table. Use the installation tool listed in table and turn the insert clockwise into the hole until the upper coil is 1/4 - 1/2 turn below top surface.

Notice: Always make sure the piston is at bottom dead center (BDC) to prevent piston damage.

Lube mandrel threads and thread taperset onto mandrel with larger end towards 11/16 hex body until one thread extends beyond the taperset. Install taperset into hole and torque to 68 N·m (50 lb ft). Hold 7/16 hex and loosen 11/16 body 1/2 turn. Remove installation tool.

To remove the tang used for installation, place the square end of a punch on the tang and strike the punch sharply.

Use compressed air to blow chips out of hole. Take care not to blow chips into engine.