I am now the proud owner of a 73 280C. It is in need of considerable work, but I enjoy that anyway. I have a number of questions but a couple of particular ones come to mind.

First off, I have been driving it for a few weeks now and the car seems to be in decent order. Four wheel disc brakes, power windows, independant suspension, these are all interesting features for an older car, thank you old German engineering! I have notice one very noticeable weak spot (as far as drivability is concerned). The transmission is a three speed automatic without an overdrive. The engine has to really wind up to meet freeway speeds. I believe that most cars weren't running at 75 or 80 mph on the freeway in the 70's, but now (at least in CA) I need to go that fast to keep from being run over. Does anyone know of a transmission that would be able to be put in that is a 4 speed auto with overdrive?

Secondly, the engine is showing signs of wear. When running at high rpms for any period of time (say 15 minutes on the freeway), the car begins to spit smoke. It is clearly oil that is burning. It takes a while for the oil to get burned out of the engine and even then has a bit of residual. Maybe the best alternative to both of the options is to upgrade to a newer powertrain? If the engine is weak and the tranny isn't what I want, something newer perhaps? I really hope someone has some insight on this as I do not know much about benzes. I should also point out that I am not under the false illusion that I will find anything to just bolt in, but the minimal amount of modifications required is of course ideal.

Thanks!

BTW, if someone wants to contact me directly to discuss this, my email is hotmail@peehs.com

-curtis

Actually, the transmission is a four speed but you probably haven't found granny gear yet. From a standing start, press the pedal to the floor to activate the kickdown switch under the pedal. You should run out of revs before you run out of intersection.

Top gear is 1:1 as were all automatics of that era. Most four speed manuals were also 1:1 in top gear. If you look at the speedo, it shows bars at the shift points. The three bars show when to shift into top gear. I wouldn't rev mine anywhere near that high but MB seems to think it won't blow up. I have had it kick down a gear at 60 miles an hour when floored though.

Also, the speed limit was in the 70's in the 70's and some states had no upper limit. Our 1969 Peugeot 504 would run 85 miles an hour all day long without seeming strained.

__________________
Usta haves '69 250/8, '76 280C, 1971 250C 114.023, 1976 450SEL 116.033
Current have, 1983 300SD 126.120

I appreciate the info, but I still don't have an answer to my questions. I also had a '63 Olds Holiday that would run very happily at 85 mph, but that doesn't make my 114 any happier.

Just out of curiousity, why the granny gear? What advantage does that have in a car that clearly isn' going to be hauling? Generally, at least in my experience, the granny is to get the car rolling under a heavy load...

-c

The best (and really, only) way to reduce highway RPMs is to get a taller rear gear. A lot of people with high-revving engines grab 4.5 rearends to lower their highway RPMs. I don't know if a 108/4.5 rear would work on a 114, but I know people with 111's do it (and ones with 108's with the 6-cyl as well).

__________________
Current:
2021 Charger Scat Pack Widebody "Sinabee"
2018 Durango R/T

Previous:
1972 280SE 4.5
2014 Jeep Grand Cherokee Limited "Hefe", 1992 Jeep Cherokee Laredo "Jeepy", 2006 Charger R/T "Hemi"
1999 Chrysler 300M - RIP @ 221k

I use the granny gear to frighten bystanders that aren't expecting an old Mercedes to spin the tires like that.

I assume its there for pulling heavy loads, but otherwise, I'm with you in that an overdrive would have been a better idea.

Michael

__________________
Usta haves '69 250/8, '76 280C, 1971 250C 114.023, 1976 450SEL 116.033
Current have, 1983 300SD 126.120

During the era of cheap gas, Mercedes geared their US-market cars to enhance acceleration from relatively small 6 cylinder engines, at the expense of economy and relaxed highway cruising.
These engines were designed for high revs, but deteriorated rubber engine and subframe mounts can amplify the 'overworked' sound these cars make at highway speeds.
New motor & tranny mounts much reduced the 'screaming to death' racket and vibration my '60 Fintail used to make on the freeway.
Several years ago, when my '72 W114 sedan's original 17 gallon gas tank sprung a leak, I upgraded it by swapping in a 21 gallon gastank from a salvage-yard '75 W114 280 sedan.
As for rear end swaps, the 280SE 4.5 swing axle rear won't go in a W114 coupe, but an open-axle differetial unit from a mid '70s - early '80s 450SE/SL or 300D might work.

Happy Motoring, Mark

__________________
DrDKW

I have a 1973 280 sedan and it took a while to get used to how it revved on the highway. I didn't drive it over 50 for a while...I thought it was going to blow up!! Actually, I've driven it lately at about 70-75 and once it gets over 60, it's pretty smooth. I agree with whoever...replacing the rubber in various places would make it pretty smooth. My rear end is a 3.92:1...if you look at the lower left rear of the rear...you'll see the differential ratio. The best way to work it is to replace with a lower rear -end. By the way, my MB mechanic told me I could run the M110 engine all day long at 6000 rpms...I wouldn't do it of course but he said it's a tough engine to kill. Plus the gas mileage would be horrendous. I think you ought to make me an offer on my sedan. The engine only has 84k on it and doesn't smoke at all.

Keep us updated on your project.

Tom in AZ

There are a range of lower ratios available. You can get as low as 3.08 vs your current 3.69 with a rear end from a 1985 300D 123 car. Also some in the 3.23 range. You can then switch the transmission valve body to one that goes to 1st at a start if you want some pep off the line.

Look for a post by Channel1 on the rear end swap.

I would suggest looking for a M110.984 988 or 990 engine and preferably the whole car, to get the injection plumbing and wiring. The 988 and 990 are euro motors with 195 HP vs your 120 or so. Believe you will also need the tramsmission.

If you can find a car with a manual trans, you will really see a perf. improvement.

I am taking a compromise route and adding the injection from a 1979 280SE to my 1973's engine.

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

Hmm

I have a 71 250CE back in england, the last time I drove it was in the late 90's but can remember how well it drove under high speed, I took the car up to 115mph once on the M4 and it fealt more solid then my 90 BMW 318i. I hate to say it but you may be experiencing a weak gearbox or engine problems. If your convinced that this is not the problem, you can always try a manual conversion. I know that these cars came with (or at least the Euro version) a 5 speed manual option.

I really miss that car, I need to figure out a way of bringing it to the US and re-restore it.

__________________
With best regards

Al

Okay, so I spoke too soon. I went on a drive with some friends to the foothills and one of the cylinder rings is now kaput. Time to look at both the engine and tranny. Anyone out there looked at possibly putting in a 124 drive train?

Good grief,

There is a guy on the list who is looking at swapping his W123 280CE Euro drive train for a US V8. Maybe you can work out a deal with him.

__________________
With best regards

Al

For some reason, when I posted last, I was not able to see all of the additional comments on the 114 motor. I don't think I am interested in changing to the 124 now given the input that I have recieved.

I have a couple of new questions now. (I am an inquisitive little bugger aren't I?!) CTaylor738 commented about at 3.08 gear set from a 300D and then switching the transmission valve body to be able to use first more effectively. Do you have more information on that? (not so much the rear end swap but the valve body change)

Also, like I mentioned in my previous post, it is engine time. I would really prefer to build it myself (have done other motors in the past and rather enjoy it), but am willing to buy the motor if I can get a decent price (found $4000 online, no thanks...) Does anyone know of a good place to buy the rebuild parts? My buddy is actually a MB mechanic and will buy me the parts I want at cost, but I don't want to abuse him...

Thanks again for all of your help. I have finally named the 114 with a bit of help from my daughter (all of our cars have been named). I am now trying to get "Gretchen" working again.

-c

www.***************

__________________
With best regards

Al

You might want to have a look at a 280 sedan that is on eBay, reported as having belonged to Johnny Cash. A pretty black one but it doesn't say what condition the engine is in:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=12&item=7316810233&rd=1
'76 was the last year for that chassis. I would not want to rebuild the DOHC 280 engine. its not easy to work on and parts are expen$ive, finding a running engine to swap in may be a better alternative. The reason these engines sound like they are revved up while driving is that they are a noisier engine than the single cam engines. Two cams and timing chain noises add up.

__________________
'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!

I have a 1973 listed in the CARS section for sale. The engine and trans are in great shape...less than 85k miles on both. $2000 for the car and although it's a sedan, there are probably plenty of other parts you could use. If you want to have your MB mechanic friend talk to my MB mechanic about it, let me know. It's listed in the Cars section of this forum. I've had a few things done to it not listed on there.

Let me know if interested,

Tom in AZ