K series Gearbox Technical Help
Hi All !! This page is to help people with everything to do with Honda K-series manual gearboxes both for road and for motorsport applications. I have personally collected this information over the last 15 years which i hope will give great insight and options for people when repairing or upgrading their gearboxes. Some of the information might seem obvious but again please remember everybody needs to start somewhere and there will be different levels of enthusiasts that visit this page with different levels of knowledge .... Thank you Steven
The K-series engine / gearbox was released in 2001 in a huge range of vehicles ranging from your everyday commuter to track ready models. Some daily commuters also came with 4wd which can be utilised in other models from track use or drag racing.
There are 3 main K series style gearbox from 2001-2007
* This is the EP3/DC5 style gearbox and uses a manual speedo drive 
* This is the Accord CL7/CL9 Style gearbox and uses a electronic speedo drive
* This is the CRV 4wd gearbox and it uses a manual speedo drive
After 2007 the gearboxes are similar to the Accord 2003-2007 gearbox with an electronic style speedo drive but with different styles of control towers ( the part that moves on top of the gearbox when you move the gear stick and this movement then selects the gear inside the gearbox )
Here is a list of genuine Honda Final Drive Gears which i have found over the years , the smaller the number the longer the gear will be when driving -
4.1 - Best suited to turbo application or ultra economy driving
4.4 - Best suited to turbo / supercharged application or economy driving
4.7 - A great ratio for a good mix between economy + performance on a naturally aspirated car.
5.1 - A great ratio for a good mix between road and track use
5.3 - This ratio is more aimed towards track use or aggressive road driving .
Here is a list of the individual gears i have come across over the years , first and second are grouped together as they have to be used together due to the non floating half of the gears being built into the main shaft. All the other gears can be put in or out of a gearbox individually.
1st – 3.266
2nd – 1.769
1st – 3.53
2nd – 1.769
1st – 3.266
2nd – 2.130
1st – 3.923
2nd – 1.88
3rd – 1.21
3rd – 1.35
3rd – 1.51
4th – 0.91
4th – 0.921
4th – 0.972
4th – 1.27
5th – 0.714
5th – 0.73
5th – 0.78
5th – 0.825
5th – 0.972
6th – 0.659
6th – 0.738
6th – 0.78
As you can see there are a massive amount of gear options for you to mix and match depending on your use for the vehicle.
Here is a link to a great Honda gearbox calculator to see what difference in speed and revs a certain gear ratio above would make in your gearbox