Cylinder head bolt hole thread is damaged Cylinder head bolt hole thread is damaged yasseremam (Mechanical) (OP) 17 Jul 16 05:33 I work on a dredger having a cat 3608 engine, the cylinder head bolt hole thread in the cylinder block is damaged, what is the best solution? RE: Cylinder head bolt hole thread is damaged GregLocock (Automotive) 17 Jul 16 06:41 Call Caterpillar? Cheers Greg Locock New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm? RE: Cylinder head bolt hole thread is damaged Tmoose (Mechanical) 17 Jul 16 13:10 Got pictures and a sketch? How did it get damaged? Heavy rust? "Drilling out" a broken bolt? If the damage affects more than 1 or 2 threads they may need to be restored. I prefer Helicoils most times. You may need an extra long, or stack 2 regulars to get enough thread engagement. RE: Cylinder head bolt hole thread is damaged catserveng (Electrical) 17 Jul 16 17:04 There are approved repair methods for repairing cylinder head stud holes in the block. Either contact your CAT dealer or In-Place Machining (they do a lot of CAT's repair work) to get it done properly. Because these heads are hydraulic tensioned you don't want to do an improper repair, or you may launch a stud during tensioning, and it can be pretty ugly. MikeL. RE: Cylinder head bolt hole thread is damaged catserveng (Electrical) 17 Jul 16 18:27 Is the dredge the "Liberty Island" by any chance? Only dredge I knew of with 3608's. RE: Cylinder head bolt hole thread is damaged catserveng (Electrical) 17 Jul 16 19:10 CAT has the 128-5113 thread repair insert, the procedure is detailed in Manual SEBF8151 Salvage and Reuse Guide for 3600 Series Engines You can only use this insert to repair one hole per cylinder. If more than one stud hole is damaged then you will need to contact someone like In Place Machining, http://www.inplace.com/ Do NOT use a helicoil, you will not be satisfied with the result. Hope that helps, MikeL. RE: Cylinder head bolt hole thread is damaged Panther140 (Civil/Environmental) 18 Jul 16 14:55 Some of these 'threads' (no pun intended), seem more suited for a mechanic's forum than an engineering forum. "Formal education is a weapon, whose effect depends on who holds it in his hands and at whom it is aimed." ~ Joseph Stalin RE: Cylinder head bolt hole thread is damaged Tmoose (Mechanical) 18 Jul 16 15:29 That 128-5113 is a pretty big thread. 10 inches long, drill and tap a 2 inch hole to salvage a 1-5/8 inch thread. http://files.engineering.com/getfile.aspx?folder=12d7c0cc-fe5d-46d8-8f08-ce [Post Deleted] RE: Cylinder head bolt hole thread is damaged yasseremam (Mechanical) (OP) 25 Jul 16 11:44 Dear Mikel, I have an old manual telling that the repair insert is 4c6409. Is the 128-5113 areplacement? Thank you RE: Cylinder head bolt hole thread is damaged catserveng (Electrical) 25 Jul 16 13:55 Yes, the 123-5113 is the current part number from what info I have. MikeL.