Date registered: Jan 2019
Vehicle: 1994 W124 E280 Facelift
Location: South Africa
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Quoted: 1 Post(s)
W124 Manual Swap - BEAR WITH ME PLEASE
Hi all. I'm new on here so I will try my best to be as detailed as possible.
A year ago I bought a 1994 registered non-runner W124 E280(M104.942) that suffered the dreaded wiring harness death(ECU got fried when harness shorted according to previous owner) as a project car. Since I live in South Africa, sourcing a rebuilt one or having one rebuilt was just not a good financial decision so I replaced the ECU with an aftermarket stand alone one called Dicktator(local brand). The car eventually started and I replaced all the relays, coils and spark plugs just for safe measure. I initially wanted an E320 but they are becoming quite rare here so I took a chance on the non-runner E280 since they are pretty much the exact same car.
Now for why I'm really here. The car was running great before we stripped it and sent it off for paint and bodywork and now that the engine is out, I have been considering converting it to manual. I have spent hours and hours and HOURS on all the Mercedes forums researching this topic but there never seems to be any thread that is 100% helpful. I noticed that the most people say the dogleg manual transmission from the 190E and R129 300 SL is the best way to go but that's unfortunately not an option for me due to the country I live in. South Africa never received many of the 190Es with the dogleg, in fact, I think the few that we have are imports. And me importing one is not an option because of the ridiculous shipping costs that would be involved. Anyway, we do however have a lot of the manual W124 300E and 260E models around here and two people have told me that the transmission from those models would work if I want to do a manual swap on my E280 but I have come across a thread on here that pretty much said its an extremely complicated job to marry a M103 tranny to a M104 engine. The reason why I want to go manual is because I want to turbo the car at some point BUT not make ridiculous power. I just feel like the M104 has a lot more to offer and would just be an overall better car to drive with a manual transmission.
Another thread I came across said you could use the transmission from a C230K because it will apparently bolt right onto the M104 but that thread was also a dead end so I have reason to believe that it's not that easy. The guy that installed and wired up my stand alone ECU told me that a 6 speed BMW gearbox from an E36/E46 with an adapter plate is also an ideal route to go but no one on this planet makes such adapter plates so yet again, another dead end. One of the guys that owns a Mercedes scrapyard(junk yark/wrecker) told me that the 5 speed manual tranny from a W124 E220 of the same year as my E280 will be a direct fit since the engines look almost identical and I was hesitant to take his word for it because I'm of the thinking that the straight 6 will eat that 4 cylinder transmission up but since he works with only Mercedes cars, I thought I should do more research on what he said.
So my big questions is, Will the manual tranny from a 300E/260E work for what I plan on doing? Finding a donor car won't be an issue since there are a lot of manuals in my country.
Will the tranny from the E220 be sufficient and survive being used on a M104?
I know this topic has been discussed to death but I honestly can't seem to reach any conclusion via the forums. I know there are lots of videos of manual swapped W124s but the owners never want to share the specs of their builds or give any advice. ANY help/advice would be appreciated. I will attach some pics of my car just so you can see it.