Repairing Wheel Bearing Housing
Information
Perform all tasks required during thread repairs manually.
Use cutting oil for thread repairs,
- Do not use a power drill,
- Do not use an impact bolter,
- Do not use tools to secure the assembly aid. Tighten fastening screw by hand.
Overview of tools > VAS 6627A - Brake calliper repair kit :
Overview of tools: Time-Sert basic set
- Assembly aid (not required for 992)
- Fastening screw, M12
- Fastening screw, M14
- Guide sleeve, M12 - internal diameter: 12.25 mm
- Guide sleeve, M12 - internal diameter: 10.00 mm
- Threading die holder
- Guide sleeve, M14 - internal diameter: 14.50 mm
- Guide sleeve, M14 - internal diameter: 12.20 mm
- Cutting oil (not supplied)
Overview of tools: > VAS 6627/8 - Thread repair set. M12 x 1.5
Tool case for Time-Sert supplement set
- Supplement set case
- Drill bit
- Seat miller
- Tap
- Screw-in tool
- Threaded bush, M12
Information
The wheel bearing housing can remain installed during thread repairs.
- The numbers shown in the illustration have the same end numbers as in the tool sets.
- For clarity, some of the repair steps are shown on the removed wheel bearing housing.
- > VAS 6627A/11 - Drilling template -1-
must be fitted on the intact thread using M12 fastening screw -2-
You will be working on the other side with the defective thread.
Fitting drilling template
- Drill out the defective thread.
- 2.1
Push drill bit -1-
with the M12 guide sleeve -2-
onto the threaded hole through the drilling template -3-
.
Drill bit with guide sleeve on drilling template
- Drill bit from > VAS 6627/8 - Thread repair set. M12 x 1.5
- Guide sleeve, M12, internal diameter: 12.25 mm from > VAS 6627A - Brake calliper repair kit
- > VAS6627A/11 - Drilling template
- 2.2
Drill out the thread as far as the stop using the threading die holder -3-
and drill bit -1-
.
Drilling out thread on brake calliper holder
- 2.3 Remove drilling template. Carefully blow the chips out of the bore hole. Wear protective goggles.
- 2.1
Push drill bit -1-
with the M12 guide sleeve -2-
onto the threaded hole through the drilling template -3-
.
- Countersink the bore hole,
- 3.1
Using the seat miller, countersink the bore hole until it is sufficiently deep to allow the stop of the seat miller -2-
to sit on the wheel bearing housing -A- (as far as the stop).
Countersinking bore hole
- 3.2
Bore hole countersunk -A-
.
Bore hole countersunk
- 3.3
Check the countersink depth at the bore hole.
Fit the M12 threaded bush -5- into the bore hole against the screw-in direction.
Checking countersink depth
- 3.4 The collar of the M12 threaded bush -5- must be sitting in the recess up to the first thread.
Checking countersink depth as far as the first thread
- 3.1
Using the seat miller, countersink the bore hole until it is sufficiently deep to allow the stop of the seat miller -2-
to sit on the wheel bearing housing -A- (as far as the stop).
- Cut thread for M12 threaded sleeve.
- 4.1
Cut installation sequence for the thread.
Tap in drilling template
- > VAS 6627A/11 - Drilling template
- Guide sleeve, M12, internal diameter: 10 mm from > VAS 6627A - Brake calliper repair kit
- Tap for M12 threaded bush from > VAS 6627/8 - Thread repair set. M12 x 1.5
- 4.2 Coat tap with cutting oil.
- 4.3 Insert the tap into the drilling template from below -arrow- . The guide sleeve is projecting slightly out of the assembly aid at the beginning. The guide sleeve will drop during the cutting process using the threading die holder.
- 4.4 > VAS 6627A/11 - Drilling template must be secured to the wheel carrier using a fastening screw.
- 4.5
Carefully cut the thread as far as the end of the bore hole (as far as the stop) using the tap -1-
and threading die holder -3-
.
Cutting thread using a tap
- Tap for M12 threaded bush from > VAS 6627/8 - Thread repair set. M12 x 1.5
- Guide sleeve, M12 , internal diameter: 10 mm from > VAS 6627A - Brake calliper repair kit
- Threading die holder from > VAS 6627A - Brake calliper repair kit
Information
Mill in/countersink the bore hole.
- The collar of the threaded bush must be at least 0.2 mm below the contact surface of the wheel bearing housing in the bore hole.
- The collar of the threaded bush must not be projecting out.
- 4.1
Cut installation sequence for the thread.
- Re-mill the bore hole.
- 5.1
Using the seat miller -2-
countersink the bore hole again until it is sufficiently deep to allow the stop of the seat miller to sit on the wheel bearing housing -A- (as far as the stop).
Countersinking bore hole again
- 5.2 Carefully cut the thread again as far as the end of the bore hole (as far as the stop) using the tap. This removes the remaining milling burrs. The tap must screw out without catching!
- 5.3
Check again to make sure that the collar of the threaded bush has disappeared in the recess. If it has not disappeared, repeat the milling process! -5-
.
Checking countersink depth as far as the first thread
- 5.1
Using the seat miller -2-
countersink the bore hole again until it is sufficiently deep to allow the stop of the seat miller to sit on the wheel bearing housing -A- (as far as the stop).
- Clean the thread
(using brake cleaner for example) and carefully blow the chips out of the bore hole. Wear protective goggles.
Information
Mill in/countersink the bore hole.
- The collar of the threaded bush must be at least 0.2 mm below the contact surface of the wheel bearing housing in the bore hole.
- The collar of the threaded bush must not be projecting out.
- Insert the M12 threaded bush.
- 7.1 Screw in the M12 threaded bush as far as possible by hand.
- 7.2
Only oil the screw-in tool! Screw in the screw-in tool as far as possible by hand. Continue screwing until the threaded bush is sitting slightly deeper in the bore hole on the wheel bearing housing.
Screwing in threaded bush
- 7.3 Then, screw the threaded bush in further using the threading die holder and the screw-in tool -4- .
- 7.4 Once the M12 threaded bush is screwed in so that it is sitting slightly deeper in the bore hole on the wheel bearing housing, you will feel the increased resistance. Continue screwing carefully until there is less resistance again.
- 7.5
The screw-in tool -4-
must screw out without catching.WARNING: Threaded bush sticking out of wheel bearing housing.
- Brake calliper can become loose.
→ The contact surface of the brake calliper must be flush with the contact surface of the wheel bearing housing
→ The brake calliper must not be supported on the threaded bush.
→ There must be NO gap between the brake calliper and wheel bearing housing.
- Brake calliper can become loose.
- Check that the threaded bush is seated correctly
- 8.1
The M12 threaded bush -5-
is inserted at the correct position when the collar of the threaded bush is below the contact surface of the brake calliper -A- Threaded bush must not be projecting out!
Threaded bush fitted at the correct position, at least 0.2 mm deeper in the bore hole
- 8.2 The M12 threaded bush is at the correct position if it is sitting slightly deeper in the bore hole -Arrows- .
- 8.1
The M12 threaded bush -5-
is inserted at the correct position when the collar of the threaded bush is below the contact surface of the brake calliper -A- Threaded bush must not be projecting out!
- Clean the thread with brake cleaner after you have completed the repair work. The thread must be free of grease and drill chips!