Is there a differenc in transmissions between a regular 300D and a wagon. - PeachParts Mercedes-Benz Forum

Stretch · #1 01-04-2011, 04:00 AM

Quote:

Originally Posted by H-townbenzoboy

The 1981 300TD used the 722.303 transmission, which is the same transmission that the W126 chassis 300SD used for most of its production run. You can put a 722.315 transmission in there from a 82-84 300D Turbo, 300CD or 300TD Turbo, but you'll have to swap out the tailcones to accomodate the 1981 300TD's electronic speedometer. If you want to save yourself the labor involved in a tailcone swap, look for a 722.303 from either another 1981 300TD Turbo or a 81-84 300SD.

Sorry to be dim - but would this work the other way round - fit a 722.3 transmission to a car that previously had a 722.1 - but keep the mechanical speedometer?

rs899 · #2 01-04-2011, 08:25 AM

Army-

Yes, the transmission will bolt up just fine to the engine, but I don't know if the 722.1 and 722.3 box lengths are the same, nor if the driveshaft connection (tripod) is the same. You would have to come up with a Bowden cable lashup to replace the bellcrank arrangement you have now. Some variants of the 722.3 had a mechanical speedo. I don't know much about the availability of 722.3xx in Europe, but I assume there must have been some 300Ds there that had auto boxes ( but they may have had 722.1s?). The 722.3 is a better gearbox, IMO- the TC is less likely to fail.

Rick

Stretch · #3 01-04-2011, 08:28 AM

Quote:

Originally Posted by rs899

Army-

Yes, the transmission will bolt up just fine to the engine, but I don't know if the 722.1 and 722.3 box lengths are the same, nor if the driveshaft connection (tripod) is the same. You would have to come up with a Bowden cable lashup to replace the bellcrank arrangement you have now. Some variants of the 722.3 had a mechanical speedo. I don't know much about the availability of 722.3xx in Europe, but I assume there must have been some 300Ds there that had auto boxes ( but they may have had 722.1s?). The 722.3 is a better gearbox, IMO- the TC is less likely to fail.

Rick

Thanks Rick - yet again I need to apologize for another bit of (almost) thread jacking - Cheers

franklynb · #4 01-04-2011, 07:13 PM

Not quite correct.

722.3's from 1980 300SD models use a different adapter plate behind the flywheel, so the top two bolt positions do not match engines using 722.1 models. I'm not guessing as I have both sets of parts on the floor in my shop.

The lengths, however, are the same.

I was amazed by the shift in bolt position -- for no apparent reason. Must've been
wrench clearance.

Quote:

Originally Posted by rs899

Army

Yes, the transmission will bolt up just fine to the engine, but I don't know if the 722.1 and 722.3 box lengths are the same,...
Rick

rs899 · #5 01-04-2011, 07:45 PM

OK now I am really confused. My 1980 300SD has a 722.120 transmission. I thought that's what they all had,

ForcedInduction · #6 01-04-2011, 09:18 PM

W116 300SD models used the weak 722.1, thats why they had overload protection that prevented extra torque from turbo boost under 2000rpm.

RichC · #7 01-05-2011, 02:03 AM

Well I have a tranny from an 82 300d ready to go.

Wish me luck.

Stretch · #8 01-05-2011, 03:20 AM

Quote:

Originally Posted by ForcedInduction

W116 300SD models used the weak 722.1, thats why they had overload protection that prevented extra torque from turbo boost under 2000rpm.

And my non turbo OM617 1981 W123 300D (what a mouthful but I want to be clear!) has a 722.118 transmission.

Is anyone out there able to post the part numbers for the adapter plates?

RichC · #9 01-05-2011, 02:04 AM

Quote:

Originally Posted by franklynb

Not quite correct.

722.3's from 1980 300SD models use a different adapter plate behind the flywheel, so the top two bolt positions do not match engines using 722.1 models. I'm not guessing as I have both sets of parts on the floor in my shop.

The lengths, however, are the same.

I was amazed by the shift in bolt position -- for no apparent reason. Must've been
wrench clearance.

I have run into the same trouble.

Switched out the adapters and all was well, luckily.