Manual conversion - PeachParts Mercedes-Benz Forum

Nykam · #1 11-09-2009, 02:16 AM

OK so here we go, first post.

I have recently bought a '94 C280 automatic and I wouldn't mind doing a manual conversion.
I could only imagine how hard it might be to source a manual gearbox and have heard the MB manual gearboxes aren't so good either.
A mechanic I spoke to thought it would be a good idea to mate up a skyline gearbox with an adapter plate...

But just how much trouble am I causing myself hauling out the auto transmission? Considering the car comes with cruise control I have nightmares of a intricate MB wiring harness sprawling from Box to Dash....

Anyone out there attempted this before?
Any information regarding the Auto-Dash integration would be greatly appreciated.
Thanks

Turbo E320 · #2 11-09-2009, 09:29 AM

Manual swaps have been done on the C280 before and it's a pretty easy swap. The wiring can be modified so you can still use the automatic ECU somehow. I there's a how-to on club202.com. Personally I would go the aftermarket transmission route. I am planning to put a 90-96 300zx 5 speed in my E320.

Nykam · #3 11-09-2009, 06:52 PM

Hey thanks for the info.

People have also suggested using a gearbox from a Supra.
I also like your idea of a 300zx box.

I am currently trying to source a 3.2L engine to build into a Turbo, so shes gotta stand a lot of Torque and Horses.
Which boxes are tougher?

Turbo E320 · #4 11-09-2009, 10:45 PM

The supra(mk4 body) V160 and V161 6 speeds can stand over 1500hp. $1500-4000 used online, some get lucky and nap them from junkyards for under 1000.
The supra(mk3 body) R154 can stand around 500hp. $500-1000 used online.
The z32 5 speed and skyline trannies have the same internals and can stand 600-700hp. $300-600 used online.

Nykam · #5 11-10-2009, 12:19 AM

Quote:

Originally Posted by Turbo E320

Manual swaps have been done on the C280 before and it's a pretty easy swap. The wiring can be modified so you can still use the automatic ECU somehow. I there's a how-to on club202.com. Personally I would go the aftermarket transmission route. I am planning to put a 90-96 300zx 5 speed in my E320.

This gets me thinking

Since I most likely would go for an aftermarket engine management system. Would I need to worry about the wiring modifications?

I want to keep as much of the original Mercedes functionality intact as possible (ABS, Climate Control, Airbags, electric seats, etc)

MAG58 · #6 11-10-2009, 04:42 PM

Quote:

Originally Posted by Turbo E320

Manual swaps have been done on the C280 before and it's a pretty easy swap. The wiring can be modified so you can still use the automatic ECU somehow. I there's a how-to on club202.com. Personally I would go the aftermarket transmission route. I am planning to put a 90-96 300zx 5 speed in my E320.

What are you using for a clutch and adapter configuration? If you're cutting an adapter or two out, PM Me, I may very well be interested.

Turbo E320 · #7 11-10-2009, 10:57 PM

I'm gonna get a steel z32 flywheel and weld the E320 flywheel triggers to it. Not hard since they are 120 degrees apart. I saw a guy do it on a 16v flywheel he was putting in his e320 that he converted to manual.

I'm going to make an adapter as well.

MAG58 · #8 11-10-2009, 11:49 PM

Are the bolt patterns the same?

Pagz · #9 11-11-2009, 12:29 AM

Quote:

Originally Posted by Nykam

This gets me thinking

Since I most likely would go for an aftermarket engine management system. Would I need to worry about the wiring modifications?

I want to keep as much of the original Mercedes functionality intact as possible (ABS, Climate Control, Airbags, electric seats, etc)

You shouldn't have much trouble if you go with a stand alone ECU,though you may need to alter or remake some or all of the engine harness,which is easy.
You will need to keep the original engine ECU for its CAN link so you get RPM on the dash,which means you need to feed it an OE pickup or an OE pickup in parallel with your aftermarket ECU.as for the transmission ECU you MAY be able to completely unplug it.

If you have ASR you will loose that,if you have DBW you will loose idle control unless your aftermarket ecu will run DBW.

The rest of the cars functions will remain active.

whipplem104 · #10 11-11-2009, 09:58 AM

No need to worry about a tcu. A '94 c class does not have one. The only electronics that would need to be modified are the neutral safety and the reverse lamps. I think that the speed input is from the wheel sensors by then.
Easy to tell, just look at the back of the trans and see if there is a speed picup.
Getting rid of the ecu would not be that big of a deal either but I would leave it in for guages and mostly idle control and cruise. Run the standalone on fuel and ignition and the camshaft and intake.

Turbo E320, you have 60-2 teeth on your flywheel and the stick flywheel from the m111 will work for the 60-2 teeth cars. On the pre '97 cars you can use the m103 or in europe m104 flywheels with 3 magnets. A buddy just bought a single mass flywheel from germany for pretty reasonable for a 3.6l in a 190 conversion he is doing. Also custom flywheels are pretty reasonable if you have one to use as a pattern or the cad drawings.

Turbo E320 · #11 11-11-2009, 10:50 PM

I think you told me about that 60-2 trigger wheel on the flywheel before lol. I forgot. Why would Mercedes change it up the last year the made the motor, owning a 97 M104 makes things so complicated....all the time.

c280nz · #12 11-12-2009, 03:59 AM

i have the old style 1994 m104 with the 3 segments and one magnet flywheel,
would i be able to hook up either a standalone ecu, ore one of the piggyback aem ecus to this flywheel configerations, or is this signal to uncommon?

whipplem104 · #13 11-12-2009, 11:44 PM

I have not seen any aftermarket setups that run a 3segment pickup. But you can easily repl yours with teh 60-2 teeth or add a sensor wheel to the front hub. If you end up running 60-2 teeth I would just get the newer flywheel. They are easy to come by and the m111 will work also for the automatics. The stick shift m111 wheel will work for the m104 also. But I think that they may be dual mass.