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6 Speed Manual Transmission Swap Guide and Harness Info.

95K views 115 replies 48 participants last post by  6sp7gen 
#1 · (Edited)
There has been much confusion with swapping a 6 speed manual transmission into a 6th gen V6 Accord. I thought I would write this post to allow people to easily understand how the process works without unnecessary reposting of this topic over and over again. As well as filling my PM box with one sentence messages asking "How do a swap a 6 speed in my car?"

The Module
Overview
The swap module allows for the interfacing of the 6 speed manual transmission with the stock Accord 4 speed automatic transmission computer.

Without the module the following feature will not work.
-VTEC
-Full rev limit
-Speedo
-Reverse lock out
-Reverse light
-Passing inspection due to CEL

Parts list
The parts used for this swap are quite simple everything is available from Honda except the harness. Try to get as many parts off the donor car as possible. Here are some diagrams of the parts needed.

You can purchase parts and view detailed diagrams at Honda parts sites such as www.hondaautomotiveparts.com and www.acuraautomotiveparts.org. I find these are great sites for diagrams which allow you to see what is involved in a swap.

Mounts
The only mounts that are required to be change are the transmission mounts. The rear engine mounts can also be changed with a CL-S mount which is stronger but is not required. For the transmission mounts use the ones from the 03 CL-S 6 speed.

Axles and Intermediate shaft
The stock axles and intermediate shaft work just fine with the 6 speed transmissions. The CL-S axles are suppose to be stronger and thicker.

Pedals
You can use either the 03 CL-S or I4 Accord pedals.

Clutch hydraulics
You can use the clutch lines from the CL-S as well as the master cylinder. I have tried using a master cylinder from a mid 90's Civic as well and it works just fine and is a good bit cheaper.

Clutch Disc, Pressure Plate and Flywheel
You can use the clutch disc, pressure plate and flywheel from any 6 speed transmission. The Accord, TL and CL all use the same clutch but the CL uses a different flywheel which doesn't matter with this harness.

Shifter and Linkages
The I4 Accord shifter and linkages are not a direct fit and will have to be modified. The only linkages and shifter that are a direct fit are the from the 03 CL-S.

Starter
The automatic starter will not bolt up to the 6MT transmission you will be one from any 6MT car.
03 CL-S 6MT
03-07 Accord 6MT
6 Speed Transmissions

6 Speed transmissions from the following cars can be used. But the Accord and TL transmissions will have to be modified slightly by welding on a stud for the shift linkage. (more on this later)
03-07 Accord V6 MT (NO LSD)
03 CL-S MT (LSD)
04-08 TL MT (LSD)

Special Preparations
Before installing the harness the mechanical aspects and stock wiring should be checked for functionality. This can done be driving the car in limp mode, by removing the transmission range switch from the automatic transmission and connecting it to the engine harness. Then by manipulating the the switch to the N or P position using a screw driver. Test to see if the car will drive. This will eliminate difficult troubleshooting due to the possibility of problems with both the car and harness.


Common Questions
Q: What car will this harness work on.
A: 98-02 Accord V6

Q: Will the harness work with a TL or CL.
A: Not yet we are working on the Type-S ECU currently. The harness might work on the 99 TL and will soon be tested.

Q: Can I use a I4 or Prelude transmission.
A: No only the listed transmission will work.

Q: Can I use this harness with the J32A2 Type-S ecu.
A: No, we are currently working on a harness that works with a Type-S motor. We hope this can be applied to the Accord, TL and CL.

Q: How can I get a harness.
A: The design has been modified for a easy install and will be mass produced soon. The first ones should be ready in around April.

Success Stories
Please let me know of any corrections.

Richie V6
99 Accord J30A1 with TL 6 Speed
99 Accord ECU

Capnff
00 Accord J32A1 with Accord 6 Speed
00 Accord ECU

MikeyMike
99 Accord J30A1 with CL 6 Speed
99 Accord ECU

JDMGRNAV6
99 Accord J30A1 with Accord 6 Speed
99 Accord ECU

Cmann87
99 Accord J30A1 with Accord 6 Speed
99 Accord ECU

2nd Gen Harness
 
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1
#9 ·
Here's some more questions for you...

1. will there be any CELs with the new harness?
2. what happens to the people with the older connectors from the first batch of harnesses? will the new ones connect with the old?
3. me and kris are going to complete his swap this week, if we test your harness and it doesn't work for the TL-p, then what? Will you come down here and test on our cars since we've been waiting?
4. will the same colored wires (2 white/1red/1yellow/1green)be used for the new harness?
5. how "adjustable" will this type-s harness be?
6. what kind of warranty will you be offering with the harness? (we all know every product ever sold gets one.)
 
#13 ·
First off this harness is only for the j30a1 ecu. To get the type-s ecu to work requires a lot more work.
1. Already answered. No CEL
2. No it wont be directly compatible but it can be made to work.
3. Thats just a risk he's going to have to take. But I have researched it and I am confident it will work. The main reason the harness didnt work on your car is because you told me the auto trans from the 99 TL was the same as the type-s auto trans. When your auto trans is more like 6th gen accord's auto trans.
4. No new simpler connections.
5. There will be no type-s harness, it will be a ECU and engine harness combo. There is no simple harness for the type-s ecu.
6. Lifetime warranty to the original purchaser.
 
#11 ·
ONE MORE THING...

Axles and Intermediate shaft
The stock axles and intermediate shaft work just fine with the 6 speed transmissions. The CL-S axles are suppose to be stronger and thicker.
They're stronger.. sure that's true.. but they will mess up. I used the CL-S axles once before on the tl-p and they eventually went bad, thought it was the axle that was defective.. got another pair of CL-S axles for free, tried those, went bad... went back to my original factory axles, no problems, and then used another set of TL-P axles and they worked fine. I wouldn't advise using the axles from the CL-S.. everyone should just keep their own axles. just fyi from experience.

I could be wrong, but i just don't want everyone going through the hell i went through.
 
#20 ·
just so ya guys know.. im not a 99 im a 00 and yes it works perfect... rich, we need toget together on a new harness.. i want the full version this round with no cels..(nobody worry i asked for a version that didnt fix the cels..Richie's Autosix(my lil name for it haha) harness's are woth the wait) how much difference in price?? will ya take a trade in??
 
#23 ·
Well ****... Received a letter in the mail... I can't drive my car until it gets inspected for registration renewal. This SUCKS. It has to pass emissions with no CELs...

Still have any idea when a harness can be made? Hanging on a string here. Can't do the turbo project or even drive anywhere (work and school) for that matter unless I drive this car to NY for registration renewal.
 
#34 ·
HEY wat up Richie! you dont know me cuz im a lil' new to this forum but, i would like to know if that is EVERYTHING i need to know to do the CL-S Tranny Swap, for example, if i make a copy of wat you wrote above, gave it to a mechanic along with my car, and as soon as the mechanic was done, there would be ZERO problems with my car as in ECU, lights going off, car not starting or anything like that? would there be glitches in this prcess?
 
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