[STPilots5150]

The transmission in my 91 300D shifts too high (3000 rpm in first gear with 1/4 throttle) and too harsh. I noticed my vacuum lines were cracking, so I moved a couple of them around and it shifted smoother, but I could not figure out how to make the transmission shift earlier. After watching a video on Mercedes diesel transmission adjustments (watch 0:15-1:55) (

), I found out the red rubber tube (black in the video) attached to the throttle linkages controlled shift timing. The problem is mine does not have the same adjusting nut as shown in the video, and it is on the left side of the engine, not the right. Does anyone know how to adjust the bowden cable on a w124 with the om602 engine?

 

[Zeitgeist]

You adjust the cross-over throttle linkage (runs over the valve cover), rather than the cable on the OM602. That's an OM603 in the video.

 

[[email protected]]

Is it possible that after changing the simple linkage bushings on my working '79 300 SD (working better than ever, actually, after lots of work) that my transmission is not dead but out of sync and adjustable? On the lift I can shift into forward and reverse, but under load, no response from transmission as to actually moving the car into working gear. How do I determine if a transmission is adjustable or shot?

 

[LeftCoastGeek]

Is it possible that after changing the simple linkage bushings on my working '79 300 SD (working better than ever, actually, after lots of work) that my transmission is not dead but out of sync and adjustable? On the lift I can shift into forward and reverse, but under load, no response from transmission as to actually moving the car into working gear. How do I determine if a transmission is adjustable or shot?

a 79 300SD is a W126, not a W124, you might want to post this in the W126 forum.

but, the cable just determines the shift points from 1-2, 2-3, 3-4 when you're accelerating, it doesn't affect it shifting into forward or reverse. its possible your shift linkage is disconnected, or mangled, or its possible your transmission is blown, hard to say from here.

 

[[email protected]]

Thx for that, LC Geek. My shift linkage is fine; I put the bushings on which may have taken up a slight amount of play, 1/4", tops. After doing that and driving 50 miles I just had no transmission, apparently unrelated to the shift linkage I'd just tightened up. What made me wonder if it was my transmission ignorance is an item Kent Bergsma at Mercedesource was touting. Making me wonder if there is an adjustment that my local mechanic didn't know about. Thx, I'll repost the question on the 126 side of things.

 

[LeftCoastGeek]

hows the ATF level ?

 

[[email protected]]

Gee. Good question. Since I haven't really thought of this car for two years and only just imagined that it was a local mechanic's ignorance that might have been the issue rather than the transmission itself, If I revisit the car I'll certainly confirm that we checked the basics, such as ATF level. Thx, DD

 

[sbaert]

a 79 300SD is a W126, not a W124, you might want to post this in the W126 forum.

Nope. a 1979 300SD is a W116. 3 speed autobox, shares nothing in common with the W124s.

 

[sbaert]

Nope. a 1979 300SD is a W116 with the OM617 5 cylinder turbodiesel. 3 speed autobox, shares nothing in common with the W124s.

 

[[email protected]]

Glad to have that cleared up. I'm working on two Benz at once: (and only inactively trying to educate myself on the '79 300 SD transmission. The '88 560 SEL is on my active "bench" though with an added degree of difficulty since the car is on an island in Maine. DD