RATCHET 8H8557 - Caterpillar

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Install Plate (1) With Bushing (7) and Bolt (8) .
Select two or three hole locations and install 188-3915 Bushings (7) and 8T-4186 Bolt (8) to fasten the drilling plate to the cylinder head. In some cases, the exhaust stud and a nut can be used in place of the M10 bolts.Note: Due to the large number of holes in the drilling plate, the holes are not marked for specific bolt locations and some adjacent studs must be removed to provide clearance for the plate. On 3126B cylinder heads, the small allen head plugs must be removed to allow the plate to sit flush on the cylinder head. If the plugs are removed, discard the O-rings and replace them with new O-rings.
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Make Sure Fastener is Centered in Hole.
Make sure the fastener being removed is centered in the hole of the drilling plate.
The exhaust manifold fasteners are taper lock studs. These studs normally do not have a large air space between the end of the stud and the bottom of the hole. It is important to check the depth of an adjacent hole to set the drill depth. Drilling too deep will cause cylinder head damage.
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Check Depth of Adjacent Hole and Mark Depth on Drill Bit.
Check the depth of the hole using an identical hole and mark 1U-8133 Drill Bit (6) to avoid drilling too deep.
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Install Drill Bushing (6) with Lock Screw (2) .
Install 188-3918 Bushing (6) in the drilling plate and secure it with a 188-3915 Bushing Screw (2) .
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Drill Pilot Hole with Drill Bit (4) .
Drill a pilot hole in the broken stud with 1U-8133 Drill Bit (4) .
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Check the depth of the hole of an adjacent hole and mark 1U-8163 Drill Bit (3) to avoid drilling too deep.
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Install Drill Bushing (5) with Lock Screw (2) .
Install 188-3923 Bushing (5) and bushing lock screw (2) .
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Drill Out Broken Fastener with Drill Bit (3) .
Install 188-3923 Bushing (5) and bushing lock screw (2) .
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Use a pick or other suitable device to remove any remaining metal chips.
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Using a tap, recondition the threads.
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Clean the threaded hole to remove all debris.