ROD 0940513 - Caterpillar

(7) Measure the inside diameter of the saddle center support bores. The diameter should be 76.17 mmØ (2.999"Ø) minimum to 76.30 mmØ (3.004"Ø) maximum for the D8K, and 114.25 mmØ (4.498"Ø) minimum to 114.42 mmØ (4.505"Ø) maximum for the D9H. If the bores are worn excessively, build them up with weld and machine both bores to the following dimensions: D8K-76.20 .03 mmØ (3.000" .001"Ø); D9H-114 .05 mmØ (4.50" .002"Ø).Main Case
(8) Inspect all weld seams and structural members for cracks. It is recommended that a dry magnetic particle power and portable electro magnet be used to check for cracks where possible. A dye penetrant can also be used for checking inside the case.(9) It is recommended that the void between the steering clutch case and the rear wall of the main case be pressure checked for cracked well seams. Oil or water leaking from the ripper mounting bolt holes is an indication that there are cracks in the weld seam inside the bevel gear and/or steering clutch case.Procedure to Pressure Check the Main Case Void
(10) Plug all the holes that lead into the main case void. The small tube above each final drive filter will have to be tapped with a 3/8" 16 tap to plug the hole. (11) Attach an air line with a regulator and a pressure gauge to one of the holes that leads to the main case void. Apply 300 kPa to 400 kPa (40 to 60 psi) air pressure to the main case void. (12) Spray soapy water on all internal weld seams. If there are any cracks, they will be indicated by bubbles. (13) If any cracks are found, repair them using the same procedure as given for the frame.(14) After repair of any cracks, again pressure check with 300 kPa to 400 kPa (40 to 60 psi) air pressure and soapy water to make sure there are no further leaks.(15) If there are any cracks in the weld seams of the bevel gear or steering clutch compartment, oil will be present in the void. This oil must be removed. If not, it will continue to leak out the ripper mounting bolt holes and give the indication that the case is still cracked. (16) Remove the plug (as shown) from the main case assembly, and check for oil in the void. If oil is present, there is the possibility of cracks in the weld seams, and the void must be pressure checked. Apply air pressure as before. All bolt holes leading to the main case void must remain plugged, including the vent tube. If the pressure check does not reveal any cracks in the weld seams, then the vent tube must be checked for leakage (each vent tube). See the following procedure. (17) Cut a section of clear plastic tubing (A) approximately 13 mmØ (.50"Ø) and 400 mm (16") in length. Install tube (A) over the end of vent tube (B) as shown. Make a mark approximately 250