Not saying dirt and grime isn't a contributor to the problem, but this bolt is *IN THERE*. The torque spec is only 45nm which is not all that tight in the grand scheme of things, but this sucker laughed at a 24" cheater handle. I'm pretty sure this is the original water pump and original fan clutch, so if that's the case they've had 31+ years to become one with each other.

The lack of clearance is a serious hinderance too. I fail to understand why Mercedes couldn't have slipped a nut behind the clutch like - oh I don't know - EVERYONE ELSE. Putting an Allen (which I've learned to HATE since working on this car) in a high debris/heat/vibration area is just asking for trouble, especially when providing only about an inch of clearance to get to it. I'm on board with using XZN for replacement, I hate Allens with a passion.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)