I bought the vehicle two weeks ago and had it checked out at a shop. PO had transmission rebuilt 10 years ago. The shop said everything looked fine except that it needed new transmission cooling lines and drive belt. I had those replaced.

Up until last Thursday, transmission felt as if it was shifting smoothly. Ever since then, it has gotten progressively worse. It started with a hard shift from 1-2. It seems to not shift when it should and then finally after hitting 3k rpms it will. The 2-3, 3-4 shifts are accompanied by a clunk when it shifts.

From reading threads, it seems like it could be a vacuum issue but being new to the game, I'm not sure where to start. Any help would be appreciated and if anyone lives in the Little Rock area I would sure appreciate the expertise.

Start by opening the hood and looking around at all the vacuum hoses and connections near the brake master cylinder area (start here and follow them all). If you can get up under the car inspect the vacuum line to the modulator that is located on the drivers side of the transmission. Sounds to me you probably have a vacuum line disconnected.

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Jim

X2

A vac hose has probably come off while the work was being done. It sounds like the vac line to the mod is not connected.
If its appropriate you may be able to get who ever did the work for you to look at it.

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Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving

I had the same symptoms on my 92 300d and after looking under the hood there were 2 vacuum lines up by the air box disconnected. hooked them up and problem went away.

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I had similar symptoms once when I got my 92 300D back from the shop....it turned out a vacuum line had been inadvertently knocked loose. It's fun when it's something that simple!

Just out of curiosity, how many miles on the rebuilt transmission? How many miles on car when transmission was rebuilt? My 92 300D has 228,000 on original....my 91 has just 96,000 miles; hoping tranny will last on it as well.

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 154k miles
06 E320 CDI "Rutherford", Black on Tan, 172k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 142k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 61k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

Alright, well, I checked modulator and the lines coming off the master cylinder. I use the term "checked" rather loosely as I have no idea what to look for except something not connected. Didn't see anything.

But...I checked by the air box and what do you know, there was a connector missing a hose. Plugged it back in, took a test drive, and it was back to normal. And that is why I get to sleep in my house tonight and not in the backseat of my car. (For those of you with "bosses", you know what I mean).

As for how many miles, I'm not quite sure. He gave me paperwork he had with the car but I hadn't looked at it (not the smartest move, I know, and I never would do it again).

Thanks all! Next DIY, replacing washer fluid pump...

It's nice when a problem is rectified by reconnecting a hose!

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1993 W124 300D 2.5L Turbo, OM602.962
2000 Chevrolet Cavalier, 2.4L DOHC
2002 Ford Explorer, 4.0L SOHC
2005 Toyota Prius, 1.5L

http://www.fuelly.com/sig-us/40601.png

You're telling me. I brought it back to the shop that had done the original work and the mechanic was talking about having to rebuild it. Thankfully, I looked on the forum and the more I read, the more it seemed like a vacuum problem. Just had to find it.

Kinda scary that a mechanic would not check vacuum stuff out first.

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 154k miles
06 E320 CDI "Rutherford", Black on Tan, 172k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 142k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 61k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

He's trying to make this months boat payment.

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Jim

Well, after this experience, he isn't my mechanic anymore. If anyone knows a good mechanic near Little Rock, AR, let me know.

Mechanics who don't know Mercedes well, don't know how important vacuum is to the transmission. They are simply ignorant.

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Cheers!
Scott McPhee

1987 300D