PAN GP-OIL 1936996 - Caterpillar

All Caterpillar ProductsReports indicate that there have been some problems with loose Caterpillar Taperlock studs that have been installed in the field.
The stud end of a Taperlock stud has a chamfer of 12° 30'. The stud is held in place when the end of the stud with the taper is installed into a hole that has threads made to a controlled depth. The threads in the hole also have the same 12° 30' taper as the stud.
The tap used to make threads in the hole for Taperlock studs must be a plug tap that has been ground to 12° 30' (plus 1°, minus 2°). A machinists' protractor can be used to measure the tap to determine if it can be used to make Taperlock threads. A visual check of a tap for Taperlock holes will show the tap to have three lead threads before the first full thread.
The threads in a hole for a Taperlock stud must be held to a controlled depth. The depth of the thread is 1.1 times the diameter of the tap. For example, if the tap is a 1/2"-13 tap, the depth of the thread will be 14.0 mm (.55") deep.
When the tap is used to make threads in a hole that goes all the way through the component, make sure the end of the tap does not go all the way through the component. If the first full thread goes all the way through the hole, there will not be any taper to hold the Taperlock stud in the correct position.
Taperlock studs must be tightened to a specific torque. The torque specifications for most Taperlock studs used by Caterpillar are shown in the chart.
During installation, 9S3263 Thread Locking Compound can be used to help prevent loss of torque on the stud. The 9S3263 Thread Locking Compound is also to be used to seal Taperlock studs in which the hole is open to a compartment which contains fluids.