So I've had a streak of bad luck trying to finish my dad's 300D 5-speed project. The first two engines we bought were too worn to be used, one needed a full rebuild and the other would have probably run better with a new chain but had some wear in the cylinders that was worrisome. We then decided to take the known good engine out of my brother's 300SD that only still had an engine in it to move it around until we got around to doing a restoration and OM606 swap. The only problem was that it needs a new RMS, the car sat for about 15 years before the guy who my brother got it from bought it so it's always had leaks. We're planning to redo all of the seals while we can (including the HG, ordered all of the gaskets we'd need from the MB dealer for the previous engine) but we feel a bit over our heads in doing this complicated seal job and the chain. I also happened across a reman head so I think I'll put that on there.


The bearing caps are off, the bearings look brand new still at 180K miles (this was really the best running 617 I've ever personally witnessed). I will check to see if the con rod bolts are in spec, hopefully they are so that can be reused.

I'm also planning to have the crank, 38# flywheel and counterweight sent off to a machine shop to have them balanced, does anyone know of a good shop near Atlanta that could do this?

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Current: 1975 450SEL, 83 300D, 88 Yugo GVX, 90 300D OM603 swap, 91 F150 4.6 4v swap, 93 190E Sportline LE 3.0L M104 swap, 93 190E Sportline LE Megasquirt, 03 Sprinter, 06 E500 4Matic wagon.

Look in my build thread for the process I used. The rear seal is a PITA but doable and mine is leak-free since the repair. There are numerous posts on doing the chain - it's not too hard as long as you're careful and don't drop the existing chain. BTW - I'm still running my old 200.000 mile chain with no issues at 5300 RPM but only a few miles/year. The chains are pretty tough. (Now that I said that out loud mine will promptly fail........)



Dan

If it is the best running 617 you have ever experienced why would you want to send it out to a machine shop to have it balanced?

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Jim

I am currently doing the same thing with my OM617 engine. Not sure of how much help I can provide as I am still in the process. I took the old timing chain completely off so I could remove the crank shaft to replace the rear crankshaft seal. I am not sure how difficult it will be to put the new chain on without the old one in place but I assume it isn't that bad. I have done it that way on dozens for old Honda CB motorcycles.


Engatwork: I think he needs it rebalanced because he is putting a flywheel for a 5 speed on it.


installing the new half seal wasn't too difficult, I read a bunch of different threads on this topic before attempting to replace it. That helped alot also just go really slowly, and as everyone will tell you roll the socket or pipe to press the seal in, do not rub it. Also make sure you use a little assembly lube on the new seal surface before installing the crank, just make sure you dont get any on the ends of the seal that will contact the other half as you will have to use gasket sealer on this part.


It also took me a long time to figure out the best type of gasket sealer to use for mating the upper oil pan to the engine block. After my research I found that you must use an anaerobic gasket maker, according to the Mercedes Source guy he likes to use Locktite 518 gasket maker so I went with that. Again I have not completed my rebuild yet (waiting for 2nd over connecting rod bearings in the mail) so hopefully some one who has done this can chime in.

Also not completely crucial especially if you wont be replacing crankshaft bearings or connecting rod bearings but you may want to purchase some pastigauges to check for oil clearance, you will need a green plastigauge for the crankshaft main bearings and a red plastiguage for the connecting rod bearings. I would suggest at the very least replace the connecting rod bearings as those seem to wear faster than the main bearings.


That is all the info I could think of to tell you at the moment. I did a lot of research on rebuilding this engine before stating and during. the FSM is great to follow along to but reading forum threads helps a lot too. Good luck, take your time and make sure you have the proper tools for everything.

Also forgot to mention, if you do end up replacing either the main or connecting rod bearings make sure you know what size you need. The two OM617 engine I took apart had the crankshaft turned so it was not using standard bearing sizes. 0.25 is 1st over , 0.50 is second over and so on

What tools do you need to tear down the engine? I have three sitting in my garage, all of them need to be rebuilt, I only intend to rebuild one.

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Nosce Te Ipsum "Know thyself"

You should have a good set of metric wrenches and sockets. up to 24MM at the very least. you will need a 27MM socket for the front crankshaft bolt. You will either need to make or purchase a universal pulled to remove the harmonic balancer. A good torque wrench will be needed for reassembly. The bolts that hold the head on will require a triple square hex socket, not sure of the size but I can check later today. for the cam chain you will need a special tool to crimp the master link, but many people have used two hammers to peen the master link successfully (one hammer on the back of the master link for support and the other to peen open end. A set of metric allen key sockets is very helpful. A large breaker bar and air impact is helpful when removing some bolts. As I mentioned in my other reply I am not finished with my rebuild so hopefully someone else who has done this before can chime in. I know you need a special tool to lock the crank so you can apply the proper torque to the front bolt that holds the harmonic balancer on. A 14mm 12 point socket is required for removing/assembling the connecting rod end caps and a 12mm 12 point socket is required for removing/assembling the flywheel.

A good micrometer and calipers will be needed for measuring wear on certain parts.

Also I don't think anyone should attempt to rebuild an engine without the FSM, mine came with my car but I believe they are available free on this forum.


Im sure I am forgetting something, if I think of anything else Ill let you know