240 4 speed swap into 84 CD questions
 

Hello, looking at all the 4 speed conversion threads got me wishing.Wow, to be 16 again and know what I know now!!!

I came across a 1979 240 4 speed parts car that's cheap and I want to swap it into my '84 CD. Since I will have the complete car, that should make it easier.

1. My questions are about the rear end ratios(how do I find info on them, which will suit me best, the one in the '84 CD now or should I plan to switch that also?

2. How do I determine if I have the correct flywheel on the 240 (I thought their was a "good" one and a "better" one,i.e. # 38)?

I have looked over most 4 speed swap threads and if there are some that are better(or helped you more) please link

thanks,
bryan

Definitely go with the diff in the 'CD. The 240D diff is a much higher ratio (3.69:1 in the 240D v. 3.07:1 in the 'CD) to compensate for the lower power of the OM616. If you go with the 240D differential, you will have very high RPM for the 617.952,which has loads more power than the 616.

As for the flywheel, the 240D only came with one flywheel (a 28-pounder, I believe). The 38-pounder you mention came in the 300D non-turbos in places where you could get a 300D non-turbo with a manual (translation: not North America!). Some people mistakenly call that the turbo flywheel, even though the OM617 turbo never came with a manual transmission anywhere in the world. They are very expensive here, starting around $350 and running up $600 :eek:. You should be fine with the 616 flywheel. Most of the conversions around here utilize the 616 flywheel because of the extreme rarity of the 617 flywheel, and a 617 turbo with a manual will never be "factory correct" anyway. You tell them apart by part numbers -- the 616 flywheel starts with 616, and the 617 flywheel starts with... you guessed it, 617!

Yeah, to be 16 again and know what we know now.

Your 84 300CD has the 3:07 Differential. To check, looking at the Diff from the rear. The lower left corner of the case has the numbers. scrape off the grease and grime, and the last three numbers are your ratio.

The 82 - 84 300D/CD/SD use this ratio.
The 85 300D/CD/SD use the 2:88
The 79 240D will have the 3:69.

If you decide to swap a Differential, then use the corresponding spedo. the Spedo is geared to the Diff. Not the Transmission.
I would just keep the 3:07 Differential.

The 240D will have the 28lb FW, they all do. This is the FW you will find most easily.
The 300D NA that were sold in Europe had a 4-spd or 5-spd transmission, and they use the heavier 38lb FW. A 300D was not sold in the North American market with a manual trans. The only way to locate one in start scounging through the PNP type Junk yards for 300D NA.

There are a few around that were brought over and sold as a Grey market car.
I found a 38lb FW after looking for 3yrs or more in the PNP`s. was in a 81 300D. this is the only one I have seen. they do show up on E-bay and here in the for sale forum. I paid $27, but had to pull it.

I would say to just install the 240 FW, get your swap up and running, and then later on if you find one, then do the swap.

Use a transmission X-mount from a 240D/280E for the 300D. the 240D manual X-mount won`t work.

This is mostly plug and play, except for shortening the front section of the Drive Line. use the 240D front section and have it shortened.

Charlie

Thanks for the replies.

When I get everything I'll do a proper thread.

Do it bt1211. I have been driving mine two years now since the change over, like it more every time I drive it. I think it is awesome, and not really very difficult to do. Buy the 240D and keep it until you know every is done right.