84 300D Turbo
 

Is anyone familiar with the small timing chain idler sprocket located above the injector pump sprocket. It is my understanding that this is used to drive a hyd. pump on the S class. This sprocket as used on my car does not have a shaft spacer and moves back and fourth (side to side) with the timing chain + 1/8 -3/16 in. Is this normal?

Lenny

Mine doesn't have a spacer on it either on any of my cars. This idler gear is used on SLS suspension, but it doesn't have to be an "S" Class. Both of my 300 TDT's have the SLS pump on the front of the ehad to keep the rear shocks inflated when loading up the wagon. I don't think this is a big problem, but how loose is your chain? Is it under proper tension?

Having worn out guide rails and stretched out timing chains are going to be a bigger problem than a little play in the idler gear!;)

yes. axial play along that shaft is very normal. It seems excessive, but quite necessary considering whats going on at the IP and vacuum pump.