if i had a manual transmission and the gear box and all the parts necessary, could i change a 2004 sedan auto to a 6mt maunal?

 

This would be a huge project. Transmissions aside, I believe that the rear diff is a different ratio between the two, and you would need a new center console, as they are drastically different between AT and MT. It would probably be cheaper overall to sell your AT and buy an MT. Maybe you could find someone sick of their MT and trade :-)

2003.5 6MT Sedan. Caribbean Blue / Graphite

 

You also have issues regarding the center console, ECU, clutch pedals, and clutch related electronics. For instance, in manual tranny cars you have to depress the clutch to start the car. That relay and necessary electronics would have to be configured.

Also, from what I know about these tranny conversion swaps is that it's extremely difficult to get cruise control to work again.

With our cars as valued as highly as they are, you'd definitely be WAY better just selling and buying a 6MT. You'd probably only take a 3-4k hit (perhaps even a less substantial hit), but would save the time/trouble/money involved in the sway (which would be over 4k).

Not to mention, selling the car used to someone would be more difficult. I wouldn't buy a used vehicle that has had its tranny swapped.

04 6MT Sedan - Z Tube, Stillen CAB, 04 Z Suspension

 

I researched this in a 3.5 altima. It was cheaper for me tor trade in my auto tranny equipped base model altima and take the trade in hit for my G sedan than it was to make the auto to manual swap, even using used parts. There was a 6 k difference in price and I lost 2 k on my trade.

The 5 MT altima tranny alone was 4,000 (FWD has diff and all )

Better Life thru Chemistry
Black on Black 03.5 Sedan 6MT - Goodyear F1 GS-D3's 225/55/17, Custom Intake Tube, HyperGround Kit, Magnaflow resonator.

 

I'm thinking that the ECU may be the biggest technical hurdle. With the "adaptive transmission", I'll bet you would have major issues.

Hell, see if you can trade it in on a barely used or program model.

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Me failed English? That's unpossible!

 

no, you just replace the ECU with one from a MT car and remove the TCU. Problem solved..........$2000.00 later

Better Life thru Chemistry
Black on Black 03.5 Sedan 6MT - Goodyear F1 GS-D3's 225/55/17, Custom Intake Tube, HyperGround Kit, Magnaflow resonator.