Description
PAI 640015-019 is a 19-piece cylinder head bolt kit for Detroit Diesel Series 50 and Series 60 engines, supplying 19 grade-12.9 steel head bolts at M16 x 2.0 x 175 mm with 12-point heads. Each bolt replaces Detroit Diesel 23530768 (sold individually by the OE). Series 60 12.7L heads use 38 head bolts total — order quantity 2 of this kit per engine for a complete head re-bolting job.
Kit Includes
- Head bolt — PAI 640015 (Detroit 23530768), M16 x 2.0 x 175 mm, 12-point, grade 12.9 (qty 19)
Specifications
| Manufacturer | PAI Industries |
|---|---|
| Part Number | 640015-019 |
| Part Type | Cylinder Head Bolt Kit (19-piece) |
| Engine Compatibility | Detroit Diesel Series 50, Series 60 (11.1L, 12.7L, 14.0L) |
| Bolt Size | M16 x 2.0 x 175 mm |
| Bolt Head | 12-Point |
| Material / Grade | Steel, Grade 12.9 |
| Finish | Black Zinc Phosphate |
| Quantity Per Engine | 2 kits (38 bolts total) for full Series 60 head set |
| Warranty | 2-Year PAI Industries |
Cross References
This head bolt kit replaces or is equivalent to the following part numbers:
- Detroit Diesel: 23530768 (single bolt P/N — 19 per kit)
- PAI Industries (single bolt): 640015
Applications
This bolt kit fits the following Detroit Diesel engine families:
- Detroit Series 60 12.7L (1987–2007)
- Detroit Series 60 14.0L (2001–2007)
- Detroit Series 60 11.1L (1987–1995)
- Detroit Series 50 (8.5L, 1992–2003)
Representative trucks using these engines:
- Freightliner Classic, Classic XL, Century, Columbia, Coronado, FLD120
- Western Star 4900, 5900, 4800
- Sterling A9500, AT9500
- Mack RD, RB (Series 60 option)
- School and transit buses (Series 50 applications)
Always replace head bolts with new on a Detroit Series 50/60 head job — these are torque-to-yield (TTY) bolts and are single-use. Order 2 kits per engine. Verify your bolt configuration against Detroit OE 23530768 before installation.
