Thread Repair: Notes

Tools Required

J 42385-400 Thread Repair Kit. See Special Tools .
J 43965 Extension Kit. See Special Tools .

The thread repair process involves a solid, thin walled, self-locking, carbon steel, bushing type insert. During the insert installation process, the installation driver tool cold-rolls the bottom internal threads and expands the bottom external threads of the insert into the base material. This action mechanically locks the insert into place.

Fig 1: View Of J 42385-400 Tool Kit

Courtesy of GENERAL MOTORS CORP.

The tool kit J 42385-400 is designed for use with either a suitable tap wrench or drill motor. See Special Tools . Limited access and larger hole repair may process better using a tap wrench. An extension J 43965 may also be necessary to drive the thread repair tooling dependent on access to the hole being repaired. See Special Tools .

Fig 2: Drilling Hole Centerline

Courtesy of GENERAL MOTORS CORP.

It is critical that the drilling, counterboring and tapping of the hole to be repaired follows the same centerline as the original hole.

Fig 3: Identifying Proper Drilling Angle

Courtesy of GENERAL MOTORS CORP.

During the drilling and tapping of the hole being repaired ensure the tooling is consistently machining perpendicular to the surface of the base material.

Fig 4: View Of Tapping Guide

Courtesy of GENERAL MOTORS CORP.

If the threaded hole being repaired has a base surface perpendicular to the hole centerline, tapping guides are available to aid in tapping the hole.

Tap Size	Tap Guide	Tape Size	Tape Guide	Tap Size	Tape Guide
-	J 42385-	-	J 42385-	-	J 42385-
6 x 1.0	729	10 x 1.5	731	14 x 1.5	736
8 x 1.25	730	12 x 1.5	732	20 x 1.5	737