On a healthy 240D, I think 85 is about maximum.
Sold my first 'noisy' automatic Miss Diesel last month. Even that tired example managed to top 80 one time, right after I first got it. Based on the three I've owned, I still think a solid body & drivetrain can make much more of a difference than a hood-pad.
Hope Miss Diesel's new owner isn't planning on much freeway commuting.

Happy Motoring, Mark

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DrDKW

Most just also feel a little uncomforatable with the engine reving so high and the simultanious noise factor. It will not hurt the block though.

It still is somewhat interesting that mercedes did not equip these standard transmisson 240ds all with five speeds. The car was not priced as an econo box at the time exactly either. I wonder if the thought people would lug the engines to death or it would have impacted the 300d sales too much?

By the early '80s, with increasing sales of the upmarket 300D, and most American new luxury-car buyer's preference for automatics, I'm amazed Mercedes continued to offer any cars in the US with a manual-shift. Indeed, the W123 240D was discontinued here after '83.
Also considering the 55 mph national speed limit, and the more up-to-date 190 series ready for introduction, Mercedes probably felt there just wasn't enough of a market here for a 5-speed 240D.

Happy Mptoring, Mark

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DrDKW

Put a 3:07 gear in it from an 82-84 300d turbo car. I had one in my 240 4 spd and it was much more pleasant to drive on the highway, fuel economy was excellent. Takeoff can be slow, so "drive it like you stole it" would apply.
Once you get used to the tall gear you will not want to go back.

Kingdoc1, I've heard from others that a gear change is the way to go. Is it hard to do? 3.07? What is in it now?
Thanks!

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2006 Jetta TDI DSG 320k miles
1997 Ford F150 325k miles 4.2L V6 "Work Truck"
2008 Tundra 225k miles 5.7L
1982 240D.....sold
1984 300D...Totaled OUCH!
1985 300D Turbo 222k miles "Dos" sold to 79Mercy
1986 300SDL 98K miles "The Beater"....sold
1987 190E 2.3 16v Euro spec 115K miles....sold

Umm. I had mine up to 80MPH today, not too loud. Not overly dramatic.

PE

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83 240D - 4 speed manual - Manilla Beige
189K miles, Tachometer mod, cool wooden shift knob from PeachParts, CocoMats, Original factory paint, manual windows, manual sunroof. Starting to add AudioWrap to this car too!

You have a 3:69 ratio and going to a 3:07 may work ok for you in Florida.

The install isn`t too hard to do. When you find the Diff., be sure to pull the spedo from the donor car, they are geared together. If you don`t change the spedo, and keep the 240`s, it will work, but wont be accurate.

Here is a DIY article on changing the Diff.
PeachPartsWiki: Replacing the Differential

Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

If you live in a rural area of florida the 3.07 may get you by. If in an urban area where you really need all the acceleration the 240d can give you. The 3.07 may impact this too much.

People that have used the 3.07 could mention this reduction in acceleration . Plus percentagewise how much. Remember those five speed transmissions are out there but you have to dig to find one.

Good luck finding a 5-speed to fit these cars. My impression is that even in Europe, they weren't a common option.
In a hilly, urban area, I sometimes wondered how well a 3.46 ratio from a NA 300D would've worked in my recently-sold, automatic 240D, which made such a racket at highway speed. Perhaps a 3.46 would've made that car more tolerable, without compromising performance too much.
OTOH, despite missing a hood-pad, my solid-body stickshift example, with it's factory replacement engine, is much more pleasent & relaxed at high speed. sounding more like a high-reving 4-cylinder gas engine, without that overpowering diesel roar.

Happy Motoring, Mark

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DrDKW

I've gotten mine up to 90 going down Monument Hill north of town

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1983 240D, 272K+ miles (odo broke)

I'm about 2 years (if memory serves-I didn't look it up) into my switch to a 3.07. Off the line acceleration improved (according to butt-dyno) with it as did 0-60 time (by about 3 sec IIRC). The 240D automatic starts in 1st gear. With the stock 3.69 on a full-throttle launch you are in 1st gear for about 7 femtoseconds. The 3.07 lets you hold 1st gear for much longer-making it actually usable-and you are still in 3rd at 60 which is something I couldn't bear to do with the stock 3.69. I live in rural Oklahoma and it's pretty flat but often windy and around 1300 MSL elevation. The only thing I remotely dislike about the swap is the faceplant the car does between 50 and 60. If you are going uphill or upwind and want to achieve a speed North of 60 you better leave it in 3rd til 60.
Do a search under my username and find my whole thread about this very topic. I have nothing bad to say and would not own another 240D auto without doing this mod.

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1983 M-B 240D-Gone too.
1976 M-B 300D-Departed.

"Good" is the worst enemy of "Great".

F.D. Ratio change on 1983 240D. First report.

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1983 M-B 240D-Gone too.
1976 M-B 300D-Departed.

"Good" is the worst enemy of "Great".

gents - I just got back from driving a 240D with 4 spd, and the notion of buddhist monk is downright accurate - you get accustomed to watching other cars speed up, it is quite loud at 70 mph but surprisingly quiet at 80, MB engineering right there, just like my E300D, a little sound at 70 - dead silent at 80 and above.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

Yes the automatic is more tollerant of the 3.07 change and really needs it. Not practical on the standard transmission 240ds though I would think.

These 240D's were built in the 55mph era. They are geared accordingly. It is also my understanding that there is no overdrive in a 5 speed or a 4 speed manual - you just get more ratios in a 5 speed with possible smoother acceleration/speed matching.

When my 240D was running, I got used to being in the slow lane but loved the way the engine hummed. It was as if the engine and the car were happy at 60 or 65mph. No need to push it.

If you want acceleration, get a 300 Turbo.

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Codifex
1981 240D ChinaBlue (Got her running with a donor engine.)
1983 300DTurbo w/sunroof.
1984 300TD manual sunroof. (Electrical Gremlins)