I finally got to drive my 1985 300D out on the freeway today. I have some shifting questions:

• Should the engine be revving @ 2700 RPM when driving at 60 mph?
• I have upshifts (light on the pedal) at 1->2 @ 13 mph, 2->3 @ 18 mph, 3->4 @ 22 mph. All of these shifts occurred with the engine at 1800 RPM.

Does all of this sound correct? Should I be tightening the Bowden cable to delay these shifts?

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Mike Frederick
1986 300SDL, 240K+ miles
1985 300D KaliKar, 270K+ miles

Tighten the cable by lengthening (backing out) the threaded collar and nut - mine is white- and it will resolve most of the early shift concerns. Be careful not to break it!

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Thanks,
Mark in NC

"Spark plugs?...We don't need no stinking spark plugs!"
1985 300SD "Der Silberne Schlitten" 420,000 mi


Wish these were diesel:
2003 Ford Club Wagon 130,000 mi

RPM's sound close to me. I've been messing with my Bowden cable a bit lately. I'm just going by feel. It seems like a compromise between getting an aggressive enough down-shift going up long steep hills, while still not seeming too touchy around town. To raise the shift points you want to turn the adjuster clockwise to lengthen the adjuster, which will allow less play in the cable. Its really easy to adjust, and with an older vehicle that you're doing regular improvements to (like mine) it seems like something that should be adjusted for driveablilty as more power becomes available. Once I'm convinced that the engine is 100%, I'll get the different vacuum orifices and do a full transmission tune - there's a good description of how to do it somewhere around here, but I can't find it just now. Just my 2 cents, don't take it as gospel as I'm a bit of a noob to Mercedes, but I am a fairly competent wrench in general.

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'82 300SD - Somewhere over 220k - Becoming reliable...

Here's some shift points for you.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

OK, so I read this to state that my 1985 300D should shift at (using a light foot):

1 -> 2 @ 7.5 mph (12 km/h), measured is 13 mph
2 -> 3 @ 20 mph (33 km/h), measured is 18 mph
3 -> 4 @ 28 mph (45 km/h), measured is 22 mph

so my car is "in the ball park", although my first shift is too late and my last shift is too early. Thanks for the info.

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Mike Frederick
1986 300SDL, 240K+ miles
1985 300D KaliKar, 270K+ miles

Hmmm, the CD doesn't seem to have any transmission info, what book is that?

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'82 300SD - Somewhere over 220k - Becoming reliable...

Don't forget the info I posted is from a 1981 300D turbo diesel model 123.193
Your's is an 85 and the shift points may be different. What is your WOT shifts? The pic is from a Mercedes Technical data manual.

I've got shift problems where I'm in 4th by 22 mph no matter how light or hard I'm on the throttle....makes it kinda slow off the line. I tried adjusting the bowden cable without any change so far.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

At full throttle your car should be screeming at around 4000 rpm's in 3rd at around 60 mph. 22 mph is WAY too soon.

Watch the tach at full throttle, it should go from 700-3500 then from 2000-3500, then from 2200-4000 (all ranges are approximate and a guess from my recollection of driving my 300SD)

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Closing the store
Benzbonz.biz on your smart phone or tablet.

I've had good luck tuning the shifts via the bowden cable at a moderate acceleration. That is, somewhere between rabbit and turtle. More like you'd drive on a daily basis. This is a good drive it and tune it procedure. Turn the bowden cable adjusting nut a 1/4 or 1/2 turn the drive. Is it better or worse? Adjust accordingly until you find the right spot.

Having those specs is nice, but those are for a fresh trans, and maybe not a 30 year old trans with 250k miles on it. There might be a better place for those shift points that creates a better shift.

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I may very well be mistaken, but I believe that 123.193 signifies a wagon. Still, wagon's were turbo in 81 IIRC.

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1982 240 D, 308,000 - 321,127 miles (sold)
1982 300 TD,166,500 - 226,000 miles
1998 E 320, 120,000 - 144,000 miles
2005 C 230 K, 26,000 - 77,000 miles (sold)

I think you are right!. I couldn't find a turbo sedan in the 1981 Tech data manual and the turbo wagon is the closest one.

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

From a standstill, I have to really stomp on the pedal to get it to shift at higher rpms. If I drive normally, the only shift I have complaint with is 3rd to 4th, which happens at 20-22 MPH, way too early. Is that a mis adjusted bowden cable or vacuum orifice issues?

__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Just leave the car in 3rd around town.

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

YES

Based on the statement that you have LIGHT foot pressure these are appropriate shift points. Your WOT shifts should be around 4,000.

If you drive with a light touch, such that you shift before 2,000 you'll tend to maximize fuel economy.

I would if I could. No matter what gear I put the selector in, it always upshifts! IDK if it's because I have loose shifter bushings or something else.

I just found out (this is a bit embarrasing) that my Bowden cable lever is swung around 300 degree clockwise! I must have unknowingly done that during the last valve adjustment. I haven't test driven it yet after correcting the situation but I hope it will restore normal shifting. This is the second item on the valve cover that can be put out of position after a valve cover R&R. The other is the IP throttle stop lever which can be jammed shut resulting in a no start. I remember wasting an hour trying to figure out why the engine wouldn't start after a valve adjustment!

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85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked