MOTOR GP-HYD 10R3228 - Caterpillar

Introduction
This instruction provides the necessary information for adding a seventh bottom roller on a D6H standard track frame for improved ride when rear attachments are not used.If a machine has experienced link scalloping in excess of 3 mm (.12 in) and there is a vibration of the machine affecting the ride, a seventh roller can be added to each track roller frame and the existing rollers repositioned. After the rollers are positioned on the track roller frame the roller guards will have to be modified and relocated. This procedure does not include the modifications required if full length track roller guards are used.Both track roller frames will have to be removed, disassembled, cleaned and throughly inspected for any signs of cracking. Any cracks must be completely repaired to provide a mounting surface for the front roller.The front track roller frame is modified to provide clearance for the additional roller. The track guard on the front track roller frame needs to be modified as well as the wear strips.The modified front track roller frame should be inspected on a regular basis for cracks. If there is any sign of cracking, a repair should be scheduled.Do not perform any procedure, outlined in this publication, or order any parts until you read and understand the information contained within.Reference: Service Manual, Parts ManualModification
* Refer to the Service Manual for the procedure and remove the track roller frames. Disassemble, clean and throughly inspect for any signs of cracking. Repair any cracks completely.Rear Track Roller Frame
(B) Premachined surface. (C) Surface if entire rail to be remachined in Step 13.1. Using the dimensions in the illustration above, fabricate the right hand rail extension block. Use a structural steel with a 290 MPa (42050 psi) minimum yield strength or equivalent.2. Locate and drill hole (A) 16.75 mm (.659 in) in diameter and 47 mm (1.9 in) deep.3. Tap hole (A) with 3/4-10 2B threads, 34 mm (1.3 in) deep.4. Locate and drill hole (D) 16.75 mm (.659 in) in diameter and 26 mm (1.02 in) deep.5. Tap hole (D) with 3/4-10 2B threads, 13 mm (.51 in) deep.6. Using the dimensions in the illustration above and Steps 1 thru 5, fabricate the left hand rail extension block. Use a structural steel with a 290 MPa (42050 psi) minimum yield strength or equivalent. The left hand rail extension is mirror image with the 7° machining reversed. 7. Remove shaded section (E) from outside sheet. Save section (E) for possible reuse after extension block has been welded in place. 8. Remove shaded section (F) from the closure plate. 9. Weld the right and left hand extension blocks in place as shown above. * Use a 12 mm (.47 in) fillet welds (G), in areas shown, to weld block to the rail.Use a 6 mm (.24 in) fillet weld (H), in areas shown, to weld block to the inside plate.Use a 6 mm (.24 in) fillet weld (J) to weld block to the closure plate. 10. Close up outside