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marcpod, Own collision repair advice
Category: Mercedes
Satisfied Customers: 2881
Experience:  i-car/Basf training, 300 repairs and 650,000 in Collision monthly 18 yrs exp/licensed adjuster
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97 s420: jumped..step guide on how to put on a new timing chain

Customer Question

Hello, I have a 97 s420 Mercedez and this morning she would not start. It sounds like the timing has jumped and I am looking for a step by step guide on how to put on a new timing chain. Do I need to pay more to get a reply, if so I am willing if its what I asked for
Submitted: 7 years ago.
Category: Mercedes
Expert:  marcpod replied 7 years ago.

Welcome to just answer. here is the procedure for you if you need anything just let me know.

Replacing and Riveting Timing Chain



  • Set piston of cylinder 1 to 45°before ignition TDC.
  • Fix right cylinder head inlet, exhaust camshafts with pins, special tool 111 589 01 15 00 (01), Fig. A.
  • Remove chain tensioner. See: Timing Chain Tensioner\Service and Repair.
  • Remove right guide rail (2) at top, install (Fig. A). See: Timing Chain Guide\Service and Repair
  • Lock timing chain to camshaft sprockets with wedges, special tool 110 589 03 59 00 (04) and (05), at right cylinder head (Fig. B).
  • Cover chain housing cover with clean shop towels to prevent debris from falling into engine.
  • Grind chain pin of timing chain (4) between inlet and exhaust camshaft sprockets open (Fig. C),
  • Pry plate (8) of timing chain (4) off with a screwdriver (Fig. D).
  • Push out ground-open double link.
  • Connect new timing chain (5) to old timing chain (4) with riveted link (6) and middle plate (7) (thickness 1.6 mm) and ground open outer plate (8).
  • Remove pins (01).
  • Remove wedge (5) at inlet camshaft Hold timing chain meshed at inlet and exhaust camshaft sprockets by hand when performing this step.
  • Slacken wedge (04) at exhaust camshaft sprocket slightly.
  • Rotate crankshaft in direction of rotation of engine with wrench socket (10); hold timing chain (4) or (5) meshed at inlet and exhaust camshaft sprockets when performing this step.

CAUTION: Ensure that timing chain (4) or (5) does not jump off when turned.

  • Pull in new timing chain (5).
  • Pull out end (4) of old timing chain which has become free from chain housing.
  • Rotate crankshaft until the ends of the new timing chain (5) can be connected with the riveted link.
  • Fix new timing chain to camshaft sprockets with wedges (04) and (05).
  • Connect ends of new timing chain (6) with link (6) and center plate (7).

  • Insert jaws for duplex roller chain with number 1 into fitting tool and screw on with screw (28) (Fig. E).
  • Insert moving thrust piece (arrow) for simplex roller chain with number 2 into fitting tool (Fig. F).
  • Insert outer plate (8) (thickness 1.2 mm) into moving thrust piece (Fig. G).
  • Fit webs (arrows) onto roller at riveted link.
  • Screw in spindle (06) until tight resistance is felt.

NOTE: When screwing in, ensure that the pins of the riveted link are inserted into the holes of the outer plate (8).

  • Remove insertion tool.

  • Turn over moving thrust piece (arrow) with number 2 (riveted section) (Fig. 1).
  • Position fitting tool exactly over center of pin (Fig. J).
  • Tighten spindle (06) to: 30 Nm (Fig. J).
  • Rivet pins of riveted link (6) individually (Fig. J).
  • Examine riveting (arrows), re-rivet if necessary (Fig. K).
  • Set basic position of camshafts, refer to Set Basic Camshaft Timing. See: Camshaft\Testing and Inspection
  • Install chain tensioner.
  • Check basic position of camshafts.


Customer: replied 7 years ago.
I really appreciate your time and effort into answering me but I already have that same information from alldatadiy. I am really looking for answers about exacts or more detail about actually the process and what new parts I have to change like any gears etc. I understand the process but I am not sure of some things I am looking at like all the points on the cam gears to match up and tools to keep them from moving while I am setting the timing. The haynes car books are so much more in detail than the computer scenario from alldatadiy but they don't make a book on this car from haynes. Are you able to give some detail on that as far as the tools that I may need, basically does autozone carry them and a little detail in the process beyond alldata. For some reason, I am intimidated with this car even though I have changed timing chains before, just looking for some one to so to speak hold my hand with advice on the issues I mentioned. Let me know if you are able to help me in that way or if I am looking for to much for the price.
Expert:  marcpod replied 7 years ago.

You know auto zone uses alldata too and they should also have books . But auto zone owns alldata know but they really may be your best bet. you can always try and talk to someone from the mercedes dealer in the parts department may be able to fax over the info to you. that actualy may be your best bet. If you need anything else just let me know.