I have a 1984 Euro Version Non-Turbo 300D. I've been having problems with it shifting HARD, espacially from 1st to 2nd gear.

I think I have a manuel transmission adjustment cable thats attached to the throttle. I've turned this adjustment and sometimes it seems to help..but then it may be just my imagination, wanting it to work right.

Even though it is a Automatic Transmission, I try to let up on the accelerator at the shift points on the speedo and that seems to help also.

I was wondering if anyone else has had this problem with their Euro Version Non-Turbo 300D..? and what they did to correct the Hard shift from 1st to 2nd. Thanks for your help..and Happy Motoring !!

The shifts on these cars are normally quite a bit harder than a similar year American car. However, it sounds like yours is shifting harder than intended. The first things to check are vacuum signal to the transmission, if your car has that, or adjustment of the throttle linkage to the transmission.

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.

Mine does NOT have a vacuum transmission modulator, that I know of.

You should have a little vacuum modulator on the back of your transmission right hand side. I'm guessing you've got a 722.3 transmission - correct me if I'm wrong.

You should be able to follow a vacuum line from the top / back part of the engine down towards the transmission...

Have a look at this thread on BenzWorld for loads of information about adjusting transmissions

DIY W123 Transmission Diagnose and Adjustment 722.xx OM 616-7 - Benzworld.org - Mercedes-Benz Discussion Forum

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

84's typically have a vacuum line going from the white vacuum control valve on top of the back of the injection pump down to the transmission. Let us know if you have one or not. Usually harsh shifts are caused by vacuum that is too low. Have you noticed any other vacuum problems with the car such as slow shut down, vents not working in the climate control or door locks not working?

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

No...my tranny number is 722.405.02.161917

There are some threads on here which address the earlier non-vacuum controlled transmission but I don't know if they're applicable to your later non-vacuum transmission. I think it was in 81 that US 123's had no vacuum controls.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

No...mine does not have that..it has a brown Vhose running directly to the ignition switch...nothing to the transmission.

Also, the Purple Vacuum line I'm talking about is too long..it extends all the way over to the AC switch and HVAC.

What purple vacuum line that you're talking about??? I don't see any reference to it. Did the shifting problem occur after another problem with a vacuum line? If so itt strongly suggests your transmission is vacuum controlled.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Well perhaps this thread will help.

http://www.peachparts.com/shopforum/diesel-discussion/105297-vacuum-diagrams.html

You might find the diagram for you car in there somewhere - see if it is meant to be there or not.

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

This vacuum line comes from a 3 way connector attached to the shutoff valve going directly into the cabin.

Is the problem with this vacuum line correlated with your hard shfting?

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Is there a way to upload pics to this site...I could take a couple pics to show where it is and where its connected in the eng. compartment.
It's not a transmission vacuum line thats for sure..I was working around the glove compartment and AC/ Heater vents area.

Ohhh wow..now i'm getting my threads mixed together...the only line running to the transmission is the cable from the throttle. There may be another one thast has a small Green vacuum valve in the line.
Hope im making myself clear now....having a senior moment..LOL

Plug the vacuum system where the purple line enters it at the y connector and see if your shifting improves.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13