80 240D: Manual Transmission engine in Automatic car (and a quick AC question) - PeachParts Mercedes-Benz Forum

WM20650 · #1 06-08-2007, 11:04 AM

Hello,

In looking for a replacement engine for my '80 240D automatic, I've found one out of a manual transmission car. Can I expect any issues, such as balance, if I run this engine with my transmission? I don't really feel like doing a complete auto to manual conversion.

As for the AC, the replacement engine has an R4 compressor that isn't seized (which means it's automatically better than mine). To try this compressor, is there anything I can do to clean it out or ensure that I have the best chance that it will work, beyond flushing the rest of the system and replacing the drier and expansion valve? It will probably have to sit disconnected with the engine for a couple weeks before I hook it up again.

Thanks for any insight!

WM20650 · #2 06-08-2007, 05:33 PM

Bump,

Thanks for any help!

winmutt · #3 06-08-2007, 05:45 PM

Honestly you are going to do most of the tran work swapping the engine might as well do it all. 616 + 4spd == bullet proof

300SD81 · #4 06-08-2007, 06:07 PM

For the compressor, depending on where your going to let it sit (wet?) you might want to get a shipping plug to put on it. I'd give you mine but the warranty papers say that it must be shipped back with the plug in if I have to exchange it, and I'm not risking it after my first one blew up on me.. I'm sure someone on here has one sitting around that they'd give you free..

WM20650 · #5 06-09-2007, 12:29 AM

"Honestly you are going to do most of the tran work swapping the engine might as well do it all. 616 + 4spd == bullet proof"

I sort of expected that answer, but in case I decide to just install the engine with the auto trans, will i have a problem just removing the flywheel and pilot bearing and installing the flex plate, or is there some work to be done to get the balance right?

Mustang_man298 · #6 06-09-2007, 02:00 AM

So long as you stick with a flex plate for the same engine you can just swap it out and be fine, it's only when you try to cross between 617 and 616 parts that you need to rebalance things. (I stuck my 616's flex plate right onto my 617 in the 80 when I put it in and it's been ok so far, but I know it wasn't correctly done as they are balanced differently). I never got the origional flywheel with the 617 so I had nothing to match the balance to.

t walgamuth · #7 06-09-2007, 07:04 AM

i am sorry to disagree with my friend mustangman but the flywheels can be either neutrally balanced or balanced with the driveshafts on all these (as far as i know) engines that come in the 123 cars. i have worked with 240s 300s and 280s and in fact most seem to have neutrally balanced flywheels and or flex plates if automatic equipped, but my 280e was not. the fsm says to treat them as if they have a fw that is balanced with the crank (i assume this is because they know that some are that way).

as a practical matter you must at least mark the fw coming off the engine that you will be using and then check it for balance. if it is neutral then you will have to check the fw that you are planning to use. if it is also neutral you are home free. if they are different the new one you are using will have to be balanced with the one coming off the engine you will be using so that it matches the crank of the engine you are using.

there is no shortcut. if you just wing it and get it wrong it will shake your eyeteeth out!

apparently the proceedure at the factory was to balance the crank neutrally as normal op conditions but if the forging was off too much they would add the fw and balance them together.

good luck.

tom w