WTB: 240D manual trans parts for conversion.
 

I have all the parts now except the 240D front drive shaft. I'm thinking I'd like to covert my 1979 300D to a 4 speed manual trans. There's a transmission I can buy locally but I'd need the flywheel / clutch, pedal assembly, clutch master cylinder and line, shifter assembly with linkage, front driveshaft section and a 240D automatic trans cross-member.


I'm in southeast Iowa 52556.


Tim

W123 pedal assy. w/new clutch master cyl. $100.

Don't forget to source the pilot bearing, clutch release arm, throwout bearing, pressure plate, NSS bypass/reverse light harness, clutch alignment tool.

My opinion is get all new everything. You would hate to pull it apart because the pilot or throwout bearing you used are trash or the clutch looks OK but is toast. If you replace one of the hydraulic cylinders, the other will often fail in short order (problems in hydraulic systems make their way down the line of leak spots).

There are two clutch master cylinder pushrod lengths. Lots of issues with these - you'll have to try both and see which one works for your application.

There are also two throwout bearings - early and late. Cutoff date for switchover is hazy, but somewhere around 81 is generally agreed upon. If the transmission you pick up is a one-piece aluminum box, you'll need the later stuff. If it is a two piece (bellhousing unbolts) then you likely need the early stuff.

Make sure that you SCRIBE a mark onto the crank and the auto trans flexplate (no paint pens that can wear off when your swap takes longer than planned) before you remove the flexplate. You will need to take this to a competent machine shop and ask them to match balance the new manual transmission flywheel to the old auto flexplate (two piece affair - don't forget the triangle ring). These engines were balanced as an assembly, and sometimes manufacturing imbalances needed to be made up in the flywheel. 4/5 times you'll get a neutrally balanced setup and have no vibrations, but if you're in the unlucky 1/5, your only recourse is to pull the crank and balance it as an assembly.

PM me if you need other advice on this swap. I had just about every issue in the book during my swap, so I am way too familiar with the intricacies.

Thanks for the advice on the flywheel balancing. The box I can get locally is the cast iron one most likely from a W115. I did find a shifter that is available from a seller in Chicago. I would still need to find a driveshaft front section and flywheel to more or less have all the bits to start with. I'll call the local machine shop and see if they can balance the flywheel, I'll also have to find someone to cut/balance the driveshaft.

Maybe what I really need to find is a therapist, my 79 300D with 87k mile on the clock is a near mint original and the auto trans works perfectly. Why can't I leave stuff alone?

I will have parts available since I upgraded from a 4 speed to a 5 speed. I’m in Chicago as well.

I found all the parts except the driveshaft front section so I still need this parts.

Tim

What rear end ratio do you have with the 5 speed? How do you like it?