IBM Power System Series Manual page 279

Figure 228: Installing the heat sink on the silver-colored TIM
5. Secure the TIM and heat sink to the socket of the system processor module.
a) Ensure that the heat sink load arms are engaged as shown by (A) in Figure 229 on page 276.
b) Tighten the center load screw clockwise by using the supplied hex key as shown by (B) in Figure
229 on page 276 until a firm stop is reached. If the heat sink moves noticeably, the load arms are
not engaged. Unscrew the center load screw and repeat this step again.
System processor modules for the 9040-MR9 275