Parts you need to replace:
Oil Pan Gasket
Front Main Seal
Water Pump gasket
Oil Pickup tube gasket
Small and Large alloy rings for chain tensioner

Parts to inspect/replace
Front main seal ring
Oil Pump rotor set
Engine Mounts
S-belt
Belt Tensioner
Timing chain tensioner
Valve Clearance Check

Special Tools
Torx for the Water Pump
Pipe cutter/hacksaw
5900 sealent
Torque wrench
Breaker Bar
Ball joint removal tool
1.4 in ID pipe to fit new seal ring
Puller to remove seal ring.
Hand held mirror
12" bit of dowel to check for TDC
MB manual on CD
Haynes Manual

I’m not going to attempt a blow-by-blow of this job-the manuals are easy enough to follow in that respect. This should serve as sort of a hitch-hikers guide instead, showing you the high-points and giving you some general advice. This job took me a week to complete and was begun when I thought I dropped a washer down the chain box when doing a valve clearance check. First lesson learned-never have more than one thing in your hand at a time when working around an open engine, the second lesson being to plug up ALL holes that small parts can dive down when doing an engine tear down. Heres some more advice to keep in mind when doing a job of this size:

3. Have lots of small cans to put nuts/washers/bolts from different assemblys into. Label all of the cans. If the bolts are of different size, punch holes through a piece of cardboard and arrange the bolts in the pattern in which were on the car.

4. Order the parts you know you need to replace before you start this job along with any parts you think might be bad. This will keep the wait time down.

5. Keep things as neat and clean as possible. Cleanliness is next to…well, its next to successfully getting your car put back together.

One major headache is the oil pan. For reasons unknown to us mere mortals, the engineers at MB refused to make the 201 oilpan a two piece affair, instead opting for a single unit that extends from the front of the engine to the back. You have the option of jacking up the car, loosening the bolts and dropping the pan 2-3 inches. This allows you to remove the timing cover with the oil pickup tube yet attached, but you can also remove it entirely. Simply (I say with a smirk) disconnect the steering dampner and drag link, and hacksaw 2.5 inches off of the end of the dipstick tube (see pictures). This keeps the end of the dipstick covered, but still lets you take the oil pan out. On the other hand, you could also remove the dipstick tube, but this method usually results in destruction of the original dipstick tube, and installing a new one is difficult.

Another problem that I ran into was removing the main seal ring. This is a ring that goes directly over the end of the crank that seals against the main seal; it also prevents the TC cover from being removed. The MB manual implies it should slip off, but there are references on the shopforum that you need a puller. The problem is that the puller has to have very thin arms to go around the ring and not hit the timing case cover. I made my own puller from a 3/8” plate of steel and 3 thin all-thread bolts (see pictures). I used a propane torch and a sledge hammer to flatten the end of the bolts, and then bent the bolts with a vice; the small 90 degree “finger” is the part that goes behind the ring. The result isn’t elegant, but it is better than using the TC cover as a puller to get the ring out-I was very worried about cracking/fatiguing it. I used a 1.4 ID X 1.5 inch piece of pipe along with the crank bolt to press the seal back onto the crank.

As you start removing the powersteering pump/air conditioning bracket, you will notice one of the bolts is hidden behind 2 oil lines that lead to the oil cooler. You will need to remove two brackets from these lines; one is located under the intake manifold, the other is attached to the block. After you have removed both of these brackets, insert the wooden jig (see picture) between the two lines from underneath the car. This will hold the lines apart far enough for you to get a wrench on the bolt that was hidden by the lines. If you don’t do this, you will be trying to hold the lines apart with one hand while attacking the bolt with the other-not easy! Incidentally-ponder that ac/ps bracket for a moment! Everything else on these bloody cars is nice, light-weight, thin wall alloy, but that mother-lover is a piece of cast boiler-plate that looks like it belongs on the titanic! The engineer who put that together must have been a holdover from the w111-123 era.

For screwing and unscrewing the crank bolt, you will need to somehow immobilize the crank. The official MB tool costs around 100 bucks and holds the engine by three teeth on the flywheel (the oil pan must be on for this method to work). Members of the board have inserted a screw driver between the flywheel and the transmission housing with success, but I actually used the butt of a rubber-handled screwdriver instead-this only works with the oil pan removed. Make sure to tighten the bolt to the proper torque with a large torque wrench-it holds the oil pump sleeve in place.

Before you start the engine, crank it through by hand twice or three times to make sure everything is perfect with the timing. After the cams and upper chain guide are back on, it can be difficult to get a read on the two holes in the cam sprokets by which you set the timing. I used a hacksaw blade placed over the spark plug holes to make sure the marks were in order-this is much easier than sighting things from the front.

Screwing in the timing chain tensioner can be a dicey affair. I had a helper man the rachet while I pushed the thing into the hole-this method seemed to work fairly well. A possible bug-a-boo is buggering the ring because it isn't seated correctly. A spot of glue will hold the ring there nicely-see the pictures for a ring that has been "fully buggered".

If anybody would care to add to this list, be my guest-I know there are three or four of you guys who have (successfully) completed this job.

Pictures:

Attached Thumbnails