The 85 300D and 300SD came with the 2.88 gearing. 84 on down to 81-82, IIRC came with 3.07. I believe the non turbo 617 had different gearing than the 3.07.

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RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

99 W210 E300 Turbo Diesel, chipped, DPF/Converter Delete. Still needs EGR Delete, 232K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Gone and still missed...1982 w123 300D, 1991 w124 300D

I have an 85 300 SD with a 2.88 rear end. With an automatic 70-75 mph is 3000 rpm (note it moves around a bit depending on the torque converter's mood at the moment). I would love a manual transmission. I dream about a CVT though.

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green 85 300SD 200K miles "Das Schlepper Frog" With a OM603 TBO360 turbo ( To be intercooled someday )( Kalifornistani emissons )
white 79 300SD 200K'ish miles "Farfegnugen" (RIP - cracked crank)
desert storm primer 63 T-bird "The Undead" (long term hibernation)

http://ecomodder.com/forum/fe-graphs/sig692a.png

Guess the consensus is my old auto was slipping more than a bit. Glad I got rid of it! I probably would not have done this were it working well, more because of the time and energy expended than anything else. Spent about $800 (donor parts, driveshaft shortening, new clutch master cylinder, rubber pedal pads, clutch plate, speedo cable, flexdisks, used crossmember), so savings over rebuilding the auto made the hours worth it.

I generally like the responsivness of the stick. I couldn't go left out of my driveway with the engine cold, it's a steep hill after a blind corner, and I could only do about 15mph until I got to the top. Now I can pull right up.

I also think it is not for everyone. With a nicely working auto, the MB drives well and comfortably, and the TC dampens driveline shock. There is a tiny bit more gear noise with the stick, and there is less "mush", so whatever play there is in the diff, couplings, flexdisks (mine are both new) gearbox, etc,. you feel when you let up hard on the accelerator. I have driven lots of sticks, and actually converted two other cars (Grand Wagoneer and a Saab 900), so I don't mind adjusting my driving. Not sure the average driver (not folks here generally) wants that much of the "driving experience".

Rleo, is the difference between the 5-sp and the 4-sp noticeable? Obviously you have better top-end rpm. Any difference starting off? Between gears?

I like the gearing of this old 4-sp, 4th is definitely a highway gear, third keeps you moving between 20 and 45 or so. 2d gear you don't have to stay in long, though you can. I may never have to rebuild this tranny, sounds fine but I know nothing about it. I figured maybe I should pick up the first cheap twin that comes along and rebuild it in my spare time.

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Peter
1985 300TD 4-speed 212K
1992 400E 343K
2001 E320 72K

5th makes all the difference in the world; it's precisely what these cars need in the age of 70+ MPH speedlimits.

Gears 1 -> 4 are the same so there's no difference in functionality there. But, 5th is about a 25% overdrive. My tach only works intermittently but at 75 MPH she's turning about 2600-2800 RPM...right in the fat middle of the torque curve. My economy has increased substantially (I never saw much change over the auto when I went to the four-speed) and, with fuel now pushing $3/gallon, it's feasable that I could eventually amortize the cost of that tranny.

Additionally, the sound level in the cabin is really reduced, making long trips much nicer. It was never terribly loud, but the wagon is overall, noiser than the sedan. The fiver makes it nice.

With your manual, do you have any gear/driveline buzz at specific RPMs?

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Never a dull moment at Berry Hill Farm.

RLeo, you make a good case for re-cutting my driveshafts when and if I ever find a 5-speed.

No driveline buzz that I have heard so far. Don't jinx me, I am still listening hard, and I have had exactly a week with this new beast. The first time I took it on the highway, it seemed noisy; subsequent trips make me think I was just paranoid, worried about the thing falling out. It seems very quiet in all the gears except lugging it up a hill you can hear the gears complaining. I have spent a lot of time in 3d and 4th, less in 1 and 2.

I was expecting vibration based on the testimonies here, but if anything it seems quieter than before. I had the driveline professionally cut and balanced, and put in the alternate 240 trans crossmember which fit like a charm, using a new 300 rear mount (much thicker than the 240). New flexdisks, fresh ATF of course.

I also have the 240 flywheel and did nothing to balance. I could not see any matchmarks on anything but the disc attached to the torque converter, so we just put the thing in where the holes matched, meaning any one of twelve possibilities! It idles smoothly, a tad higher obviously, and not a whisper of anything suggesting major imbalance. The long term results will hopefully bear out what others have found about using the smaller flywheel.

By the way, my tech found me a nice wooden (zebrano) shift knob that is not only pleasanter than stock, it is also shorter by 1.5", shortening the throw and the height above the console. Any interest, I'll find out who and where. I think it was $75 or so. Pricey for frills, but it helps convince my family that my 22 year old car is not just a beater! I don't understand them....

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Peter
1985 300TD 4-speed 212K
1992 400E 343K
2001 E320 72K

You make a good point, vstech. I have not done the math with the larger tires. I'll factor that in when I get around to measuring.

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Peter
1985 300TD 4-speed 212K
1992 400E 343K
2001 E320 72K

Do you mind sharing with us the mercedes part# ang getrag part # of your tranny?

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'85 300D Cal 280,000 miles
'14 GLK 350 60000 miles

The number on the Mercedes box is a casting part number. It starts with 115...no other tranny number per se.

The Getrag has a stamped number on it but I cannot recall what it is. I'll be doing some work on the car next week and it will be on the stands. I'll get it then and post.

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Never a dull moment at Berry Hill Farm.

Its not 115 261 2501 is it? I read in the archives that this was a 4 speed.

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'85 300D Cal 280,000 miles
'14 GLK 350 60000 miles

Methinks N/A engined cars have 3.69:1 ratios.


And, I can state without a doubt, the speedo drive gearing differs between the manual and automatic transmissions. I don't know about all manual transmissions but, the speedo outputs on the old cast iron 4-speed I had and, the Getrag 5-speed that's in the car now are both the same.

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Never a dull moment at Berry Hill Farm.

a few things.

first the na 300ds have 346 gears, the 240 123 has 369 gears.

second, the output on the speedo is off the tail shaft of the tranny so if the torque converter is slipping it does not know anything about it so the speedo has no need of a different gearing.

you should always get better economy with a stick all other things being equal, less slip and it takes less power to twist a manual tranny than an automatic (these old ones anyway).

Glad you are enjoying your manual conversion. I am too.

Tom W

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

I changed my diff from the 3.69 originally used for the 240D to a 3.46 from a non-turbo 300D. My economy went from 23mpg to 25.4mpg.

And the fiver takes that one step farther. Cruising at 70-75 and regularly seeing 26+ MPG. Even 2.88s on these cars spin the engines too fast at today's highway speedwhen running an auto or 4-speed.

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Never a dull moment at Berry Hill Farm.

.........until you wish to climb a grade..........then you realize the 2.88 is too tall.

I love the 2.88 in the SD, but, it needs maximum power to hold 65 mph on a "decent" highway grade. I've got to find out the actual grade on a the worst offenders.........I'm curious as to the grade percentage and the capability of the SD.

Of course, you have the benefit of a 5-4 downshift if you encounter such conditions.

I briefly considered swapping in a complete subframe from the parts '85 300TD I have. I addition to a 2.88 rearend, it has low mile trailing arm bushings, rotors, pads and e-brake shoes (all R&Rd in late 2004). But, after driving the car with the 5-speed, the 3.07 gears are perfect.

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Never a dull moment at Berry Hill Farm.