Thread Inserts, Repair

NOTE: Repairing of internal threads in cylinder block, intermediate section and cylinder head is done with the aid of thread inserts. Some threaded bores cannot be repaired in this way, as there is insufficient body in the threads. (The tables below also list bores which should not be repaired.)





Thread Inserts
- Thread inserts are made of cold-extruded wire to ISO thread section, of stainless, acid-resistant steel. Inserts are designed to be used in holes bored and threaded as per standard insert thread tables.
- Thread inserts have a fitting pin with break-off instructions. This fitting pin must be knocked off after installing.

Procedure:





1. Drill out the hole to be repaired:
- Select the drill diameter and drilling depth from the thread insert tables.
- Do not lower hole edges: We recommend a slight levelling only.





2. Thread the hole using the die for the thread insert:
- Use the right die for the material and circumstances in each case.
- Example, for a threaded hole size 10 mm use an 10 mm thread insert.
- Thread to the right depth (see table in step 6 or 7).
- Blow hole clean.
- Select thread insert of correct length (see table in step 6 or 7).





3. Put thread insert in fitting tool:
- Put thread insert with fitting pin downwards.





4. Install thread insert:
- Hold fitting tool straight over threaded hole. Wind thread insert in. When installed, thread insert should be about one turn below the top of the hole. If the hole is open-ended, the thread insert must not project out of the bottom of the hole.





5. Knock fitting pin off:
- Knock fitting pin off with pin breaker. Do not use fitting tool.
- Remove fitting pin and blow hole clean.
- Use a bolt to check that threads are clear and that the thread insert is installed correctly.
6. Repairs to cylinder head and camshaft casing:
- The table below shows which threaded holes in the cylinder head and camshaft casing can be repaired and which thread inserts to use.

NOTE: Holes marked B2 and V3 must not be repaired using thread inserts.

Cylinder Head And Camshaft Casing Thread Repairs (Part 1 Of 7):

Cylinder Head And Camshaft Casing (Rear View) Thread Repairs (Part 2 Of 7):

Cylinder Head And Camshaft Casing (Front View) Thread Repairs (Part 3 Of 7):

Cylinder Head And Camshaft Casing (LH View) Thread Repairs (Part 4 Of 7):

Cylinder Head And Camshaft Casing (RH View) Thread Repairs (Part 5 Of 7):

Cylinder Head And Camshaft Casing (Top View, Cylinder Head) Thread Repairs (Part 6 Of 7):

Cylinder Head And Camshaft Casing (Top View, Camshaft Casing) Thread Repairs (Part 7 Of 7):

- The table also gives details of drilling depth and diameter and the part numbers for each thread insert.
7. Repairing cylinder block and intermediate section:
- The table below shows which threaded holes on the cylinder block and intermediate section can be repaired and which thread inserts to use.

NOTE: Holes marked H4, H5, BV3, BV5, BV10 and BV21 must not be repaired using thread inserts.

Cylinder Block And Intermediate Section Thread Repair (Part 1 Of 9):

Cylinder Block And Intermediate Section (Underside, Intermediate Section) Thread Repair (Part 2 Of 9):

Cylinder Block And Intermediate Section (Underside, Cylinder Block) Thread Repair (Part 3 Of 9):

Cylinder Block And Intermediate Section (LH Side, Cylinder Block And Intermediate Section) Thread Repair (Part 4 Of 9)):

Cylinder Block And Intermediate Section Thread Repair (Part 5 Of 9):

Cylinder Block And Intermediate Section (RH Side, Cylinder Block And Intermediate Section) Thread Repair (Part 6 Of 9):

Cylinder Block And Intermediate Section (Top View, Cylinder Block) Thread Repair (Part 7 Of 9):

Cylinder Block And Intermediate Section Thread Repair (Part 8 Of 9):

Cylinder Block And Intermediate Section Thread Repair (Part 9 Of 9):

- The tables also show drilling depth and diameter and the part numbers for each thread insert.