Broken oil pump shaft

[Thom Pintello]

I'm sure a few of you have been here before. You can't figure out why the car won't start so you check your connections...nothing. You then go into the distributor to check your point gap, you grab the rotor to remove it and...the rotor turns in your hand! It's not supposed to be able to do that. So you remove the distributor and find that the shaft which drives the distributor is turning freely down inside its little recess. Oh joy. Just what I need, another project. Here's my question: What's the easiest way to remove the oil pump on a 1969 280 SEL and are there any tips anyone can offer? I'm thinking of welding the two pieces back together since this oil pump has gobs of pressure and the weld will probably be stronger than the original joint. Any thoughts on that too? Thanks in advance.
Thom

[Benzmac]

The only thing that is broken is the little brass gear that is located under the plug on the left front of the engine. (this is the side of the engine that is to your left as you are sitting in the car.

There is a replacement part and it can be replaced from the top in about 30 minutes.

I hope you get away this easily. I did on my '68. It ran fine after the repairs.

[Thom Pintello]

BenzMac! Can you give me some details on this? Where is the plug? Inside the recess or is it accessed from a different spot? If you want you can also reach me at pintello@jps.net
Many thanks.
Thom

[Thom Pintello]

Thanks for the advice BenzMac. It gave me the impetus to go back and play with the whole thing to see what the heck you were talking about. Here's where we stand: The oil pump drive shaft on this Benz must be made up of segments that interlock or something like that. When the distributor is removed one can rotate the oil pump drive shaft clockwise but not counterclockwise. What's up with that? There are particular spots around this 360 degrees of motion that work ie: If you put the distributor back in it will not engage the oil pump shaft fully and you will be able to turn the rotor by hand even while pushing down hard on the distributor. I can't see how this operates from my vantage point. However, there are some spots on that 360 degree circle that "catch" and the rotor won't turn either way when the distributor is re-inserted. I then start the car and fine tune the timing and it runs OK, but.... what the hell did I do? I don't quite understand it fully but the car runs very well, as well as it did before anyway. Does anybody know the particulars of this bit of Benz lore? Any info would be greatly appreciated. Cheers.
Thom