Crusing down the Interstate in a 1981 240D and all of a sudden there are VERY loud noises coming from under the hood. Temp gauge pegs out and alternator light comes on. Being a smart guy, I decided to pull over and take a look.

The plastic fan had all of its' blades broken off, the belts were hanging from the part of the engine that was not busted and the crank drive pully was laying in the fan cowl. Using all my mechanical powers I sized this up as not good.

Towed the car to the house and found the problem: The bolts holding the crank drive pully had sheared off. Everything turned OK, so I just started removing things until I got the parts to where I could get the remaining parts of the bolts out and then I just replaced the bolts with the strongest I could find. Of course I also replaced the fan. While I was in there I also replaced the front crank seal, but that was just because I was in there.

I am aware that on 114/115 cars the bolts holding the steering gear need to be replaced now and then, but are the crank pully bolts a normal wear item?

Anyway, I just thought I would post this so others could know about this problem. Replacing the bolts is an easy job (unless they are sheared off) and might be something to plan on. I don't remember the size of the bolts, but you could pull one out and take it to a bolt and fastner retailer and they could order them for you.