The last pic is the chain tensioner on the oil pump change. You do not want it to break at speed:(. This pic is where you have to go to find it:).

Take my advice, replace the water pump while you are doing this work. It's a PITA to get to all the bolts while the head is on and the intake manifold is in the way of the top rear bolt. The two lower bolts are down low and hidden by such things as the tensioner and the PS pump.

IMHO, replace all the guides while you're at it. Cheap insurance and it's apart anyway.

It will cost more in the short term but is cheaper in the long run.

The parts are on order, and all im trying to do now is get that special tool to hold the crank still for when i take off the pulley,, im hoping no little pieces of plastic fell down into the timing chain area,, will i be able to see all the once i have the front cover off or will i need to use a light??

A little trick to get the crank bolt loose..

I have never done this on the Benz, so i have no idea if it's possible to do. But on other cars i have often used a neat little trick to get the crank bolt loose.

Use a wrench with a handle long enough to rest on the floor. Or use a piece of pipe to extend the lenght of the handle so that it does rest on the floor.
-Turn the engine over for short second and voila! The bolt is loose. ;)

Freestyler

Do a search on this site and you will find the tool part number. I forgot to look at it when I got home last night. If I can remember I will look at it and post the p/n.

I second the opinion on replacing the water pump while you are in there. Makes the job awhole lot easier with the head off.

By doing the guide rail i assume that the radiator must be removed from the looks of it,,, Arent the transmission lines hooked intot the radiator, and if so what precautions should i take?

Just disconnect them and make sure you cover them to prevent dirt/debris from getting in there.

The radiator does not have to come off!
 

Everything else behind the radiator has to come off, including hoses but, not the radiator hoses.:cool: