What I have done in the past to obtain information from the Dealer. Go in to the dealer parts counter. Inquire about purchasing engine parts in the timing chain system with your VIN in hand. They should have a diagram with all of the parts that go with your system on the car. A print out with the diagram is usually available from them for free. be sure to ask for the parts list with the part numbers on it. Tell the counter that you need to have that list and diagram in order for your mechanic to find the correct parts to buy from them. You should walk out the door with a diagram and corresponding part list of your timing system. Bring this and upload here and or cross check the parts listed here in the parts catalog with the 500sec/sel. You may have to search for later years. eg 1985. If no match is found then google each part number separately. One thing I recommend buying at least, is the chain tensioner and rails from the Dealer. Make sure you get the IWIS chain not from dealer, as you will save on that right here . IWIS is the original maker for MB.

__________________

Chris
84 280sl
82 300d euro