Interstate Mcbee is proud to offer replacement pins and rollers for Cummins © ISX / QSX engine applications. These replacement pin & roller kits offer an economical repair of the rocker arm assemblies for this popular engine series.
Over the many years of production, there have been numerous updates to the valve train components for Cummins ISX / QSX engines, several of which included new roller geometry. This has resulted in different sized valve rollers in service today.
The purpose of this post is to illustrate the difference in roller sizes so they can be easily identified. A proper measurement is taken at the axel pin hub, which is the widest part of the roller. Shown below are precise measurements for the different sized valve rollers. Measurement of the roller is easier when removed from the rocker arm.
| Part # | Description | Roller |
| M-3679487PR | Pin & Roller Kit – Valve Rocker | 14mm (M-3979336) For Twin Cam |
| M-4026780PR | Pin & Roller Kit – Valve Rocker | 15mm (M-4059322) For Twin Cam |
| M-4026779PR | Pin & Roller Kit – Valve Rocker | 15mm (M-4059322) For Twin Cam |
| M-4319030PR | Pin & Roller Kit – Valve Rocker | 17mm (M-4319026) For Twin Cam & Single Cam |
| M-4319029PR | Pin & Roller Kit – Valve Rocker | 17mm (M-4319026) For Twin Cam & Single Cam |
| M-4312003PR | Pin & Roller Kit – Injector | (M-4319027) For Twin Cam & Single Cam |