I just bought a 1981 300SD which is being shipped to me. The PO describes a transmission problem as follows;

1st to 2nd gear flare - if you let off the accelerator petal, it switches to second immediately. 2nd to 3rd to 4th - no problem.

I searched the forum and found info on K1 spring, B2 Piston and vacuum adjustments. The info I found relates to 2-3 and 3-4 flare regarding the K1 and B2 problems.

Do you think the 1 to 2 flare is also K1 or B2 related? Your advice would be greatly appreciated, since I hope to do the repairs myself.

Thanks

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1961 220SB Hydrak
1966 230S - Too Good for Parts
1981 300SD - now in Oakville

Could be B2 related, but not K1.... Or it could be as simple as some vacuum or modulator adjustments. You'll just have to get your hands on it and start tuning..

it could just be that you have some vacuum leaks, and maybe need to adjust the bowden cable on the throttle linkage...

but also, the B2 affects 1-2 gears, but i think if it were busted it would slip really badly, more than just flaring...im only going by my single experience, though...my B2 piston went out and made my transmission slip really bad when in 1st or 2nd gear...when i got up into 3rd and 4th i had no problems at all, it seemed....the B2 piston job would be a major pain to go through and not have to...id check the vac system and do some adjusting on the bowden cable before anything else

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1985 300SD 192,000miles...Astral silver/ Grey MbTex

1983 300D 194,000miles...White/Tan MbTex...my newest addiction

Thanks -

What actualy happens to the B2 piston when it has a problem - Does it actually break or does it jam up and fails to move? Can you tell by looking at it if it is gone? Can it be fixed or just replaced? The part is over $100.

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1961 220SB Hydrak
1966 230S - Too Good for Parts
1981 300SD - now in Oakville

when it fails, it breaks up into about 5 or 6 pieces....heres a pic of a broken one, and one of a new one....i got these pics from www.mbz.org ...if you go there and click on "articles", and then look for the B2 article listed under transmissions, theres a whole writeup about symptoms as well as instructions for repair

Attached Thumbnails

 

__________________
1985 300SD 192,000miles...Astral silver/ Grey MbTex

1983 300D 194,000miles...White/Tan MbTex...my newest addiction

http://www.peachparts.com/shopforum/attachment.php?attachmentid=23407


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1985 300SD 192,000miles...Astral silver/ Grey MbTex

1983 300D 194,000miles...White/Tan MbTex...my newest addiction