Hey there, I'm currently in the process of swapping out the engine in my '81 300D. Piston No. 5 was hanging out of the end of the block when I bought it so it was time for it to go. I bought a new engine from an '80 300SD, but it came without a flywheel or harmonic balancer. This is the problem.

So here is my question: Without the old flywheel available to me, will the one I currently have be alright to just bolt on? If not what can I do to restore some sort of balance to the drivetrain? I'm stumped and on a time limit with this engine install. Any advice will be greatly appreciated. Thanks.

Most of the engines used neutrally balanced flywheels. So if you're feeling lucky, you could just get a random flywheel, have it checked for neutral balance (even that part you could skip) and slap it together and see what happens. If it tries to shake itself apart when you start it, then you probably didn't get lucky.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.

Most engines have neutrally balanced flywheels but some do not. In this case you have 12 possible positions so if its not neutral your odds are not so good, but if you don't mind investing some labor you can start with it one place (mark it) and if its not good start moving it around til you get it right. I suspect you can start up the engine without the tranny on it so you save that labor.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

The engine will run fine without the transmission, you just need to bolt the starter to the adapter plate. Personally, I've never heard of a balanced flywheel that wasn't indexed to the crankshaft so that it could only be installed in one position.

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'83 300D, 126K miles.

You heard it here.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.