pmcd404

1997 E300. my serpentine belt tensioner bearing pin, which secures the whole tensioner assembly on a diesel, unscrews itself over time. I am able to screw it back in using vise grips but I'd like something more permanent. The shop manual tells me to remove and reseal the facing before reinstall. I'm assuming they mean Loctite or similar. Problem is, I can't tell what kind or size of tool is called for to screw/unscrew the bearing pin. It looks like large socket of some kind. Any ideas?

Plutoe

If you are talking about the bearing pin, as you know it is recessed and can only be tightened properly with the correct metric sized allen key(100Nm torque).

Additionally make sure that the spacer is installed between the lever and crankcase before torquing. Never repeat never use a loctite on that bolt!!

pmcd404

thanks a lot for the good advice - and your comment about loctite. What does the manual mean when it says 'clean and seal the surface of the assembly' before re-installing? Perhaps gasket compound? Thanks again!

Plutoe

The bearing pin surface should be oiled and the spacer repeat spacer cleaned before install.

The spacer is there to make sure the lever does not come in contact with the crank case------my guess is that who ever removed the lever before never replaced the spacer, ie problem!!---no loctite, gasket compound, maf spray or BS spray--nothing.

kingbaka

17 mm allen is the size.