There’s a ton of small details and confusion surrounding K-swaps and the K-series shifting system in general. Hopefully this article can help set you straight. K-series shifting system can be broken down into 3 sections:

  • Shift mechanism
  • Shifter cables (w/respective bracketry)
  • Shifter box assembly

The shift mechanism is mounted on the K transmission side and dictates what cables and shifter box you can use. The shifter cables are what bridge the shift mechanism to the shifter box assembly. The shifter box is the shifter box – the device that allows one to  “bUsS tHrU GeArZ”. Thankfully, companies like Hybrid Racing, Acuity, and K-Tuned offer awesome K-series shifting system  upgrades and particular solutions for certain K drivetrain scenarios.

Shift Mechanism.

There are 2 main types of shift mechanisms Honda uses on K-series manual transmissions. For the sake of simplifying details, I’ll title early model shift mechs as “Type-1” and the later model as “Type-2” with suffixes for 5spd and 6spd. 6spd shift mechs have an integrated reverse lockout solenoid while 5spd shift mechs do not. What’s a reverse lockout solenoid? It’s a safety feature Honda integrated into the 6spd transmissions because of the close shift gates these transmissions have. It’s as solenoid that prevents one from accidently shifting into reverse and blowing up their trans while moving forward at speed. Reverse gear is just to the right of 6th gear in the K shifting H-pattern. So you can guess why miss-shifting into reverse can be a possibility during some spirited driving when shifting from 5th down to 6th. Thanks…Honda? Type-1 shift mechs are found on the following vehicles:

  • 02-05 Civic Si (m/t 5spd) (+ JDM variants)
  • 02-06 RSX base (m/t 5spd) & Type-S (m/t 6spd) (+ JDM variants)
  • 02-06 CRV (m/t 5spd)
  • 03-08 Element (m/t 5spd)

Type-2 shift mechs are found on the following vehicles:

  • 06-11 Civic Si (+ JDM variants)
  • 03+ Accord (m/t 5spd)
  • 04-14 TSX (m/t 6spd) (+ JDM variant)

Shift mechs can be swapped around to virtually any of the K-series manual transmissions, but there are caveats when doing this. Type-1 + Type-2 shift mechs do not share the same body bolt patterns, so its not a bolt-on and go affair.

K-series Axle Measurements

Note: All axle measurements were taken end-to-end fully compressed (against a wall). photo soon.

  • 02-03 EP3 Civic Si (4×100): Driver: 24″ Passenger: under 22.5″ (exact measurement soon) Outboard spline: 32mm Shaft diameter: 25.3mm Note: runs a short passenger side axle for some dumb reason. The driver side axle is fine to use on legacy chassis k-swaps. Steer clear of the passenger side tho, only useful for donor parts excluding the shaft.
  • 04-05 EP3 Civic Si (5×114): Driver: 24″ Passenger: 22.5″ – 22-5/8″ Outboard spline: 32mm Shaft diameter: 25.3mm Note: (1) same 5 lug + axles found on Base RSX. (2) Best axle choice for legacy chassis k-swaps with native 32mm 4-lug or USDM ITR/JDM EK9 CTR 32mm 5-lug conversion.
  • 06-11 Civic Si: Driver: soon Passenger: 23-5/8″ – 23-3/4″ Outboard spline: 36mm Shaft diameter: 26.3mm Note: (1) Passenger side axle HIGHLY recommended for legacy chassis K-swaps with 36mm 5-lug conversion + RSX Type-S drive side axle. (2) For legacy chassis kswaps with Karcepts 36mm 4×100 hub users, it is suggested to swap inboard joints if using these axles.
  • 02-06 RSX Base (5×114): Driver: 24-1/16″ – 24-1/4″ Passenger: 22.5″ – 22-5/8″ Outboard spline: 32mm Shaft diameter: 25.3mm Note: (1) MT + AT axles are the same length. Half-shafts are NOT the same length (auto is shorter). (2) same 5 lug + axles found on 04-05 EP3 Civic Si. (3a) Best axle choice for legacy chassis k-swaps with native 32mm 4-lug or USDM ITR/JDM EK9 CTR 32mm 5-lug conversion. (3b) Best to swap inner joints to gain some additional length on the passenger side but isn’t mandatory.
  • 02-06 RSX Base + 04-05 Civic Si w/swapped inner joints: Driver: 24-1/16″ – 24-1/8″ Passenger: 22-7/8″ (nice gain!) Outboard spline: 32mm Shaft diameter: 25.3mm Note: Swapping of the inboard joints only works on factory OEM Honda/Acura axles. This will not work on any aftermarket axles. Again, swapping of the inner joints with these axles is suggested but not mandatory to help gain some additional passenger side axle length for peace of mind. When joint swapping, the tripod bearings are married to their joints and not the axle – so don’t swap the bearings!
  • 02-06 RSX Type-S: Driver: 23-5/8″ Passenger: 22-5/8″ Outboard spline: 36mm Shaft diameter: 26.3mm Note: According to Karcepts findings, swapping of the inboard joints with these axles is suggested for proper axle length when using Karcepts 36mm 4×100 hubs on legacy chassis kswaps.
  • 01-05 JDM RSX Type-R: Driver: 25-1/4″ Passenger: 23-3/8″ Outboard spline: 36mm Shaft diameter: 26.3mm Note: longest factory RSX axles
  • ProFab: Driver: 23-7/8″ Passenger: 23-1/8″
  • Hasport (EGKAX): Driver: 24-1/4 Passenger: 23-1/2″

OEM Axle ingredients

  1. Using a pair of the following factory K-series axles:  02-06 RSX Base, 04-05 EP3 Civic Si, 02-06 Type-S, or 01-05  JDM RSX Type-R. Depending if your vehicle was originally 4-lug or 5-lug converted, will help dictate which model axles you need to use. Specifically what your wheel hub accepts – either 32mm or 36mm outer joint size. Note that inboard joint swapping ONLY WORKS ON FACTORY OEM AXLES. Aftermarket axles are incapable of joint swapping due to manufacturing irregularities and inconsistencies (especially China made parts store axles). Aftermarket companies such as Karcepts, offer replacement wheel hubs that accept 36mm axles but retain a 4×100 lug pattern – the axle info here applies to these hubs. What about Accord or TSX axles? They’re overall too long (both half-shaft and axles) to use for legacy chassis k-swaps.
  2. Swapping the inboard joints is key! Doing this forces the use of the whole driver side axle onto the passenger side of the vehicle and the passenger side axle onto the driver side of the vehicle. The point of this is to gain maximum and proper axle length on the passenger side of the vehicle getting it as close to 23″ inch length as possible.  Swapping is not mandatory but is HIGHLY SUGGESTED. Especially with Karcepts hubs (or similar copycat hubs) and for vehicles that are too low with a tucking tire.

Application Scenarios

  • 4×100 with 32mm axles If your vehicle is 4-lug like most civic/integra’s are (excl. Type-R), you will want to use a pair of factory RSX Base model axles. Base model axles, by default, have the the 32mm splined outer joints. Base axles will plug-n-play into any legacy chassis with 4×100 front wheel hubs. Simply swap the inner joints, install axles, and you’re done. EP3 axles can be used but with caution, see below in the Alternative axle section. Note: I’ve found that swapping inner joints is not even really necessary for Base axle use. It’s more of a peace of mind thing. I’ll leave the joint swapping choice up to you.
  • 5 Lug 32mm axles If you have converted to US Integra Type-R or JDM CTR EK9 5 lug (aka 32mm 5 lug) on your legacy chassis, RSX Base model axles are usable as well. The US Type-R 5-lug front wheel hubs cater to the outer axle spline joints that utilize a 32mm axle nut-outboard joint. Simply swap the inner axle joints, install axles, and you’re done. UPDATE: If you find that your passenger side axle does not seem to have enough length or you’re experiencing passenger side axle issues, you should quickly upgrade to an 06-11 Civic Si passenger side axle and swapping your 32mm outboard joint onto the Si axle.
  • 5 Lug 36mm axles If your vehicle has been converted to JDM ITR 5-lug w/36mm splined outboard joint, the RSX Type-S or RSX Type-R axles are the ones for you. 98+ JDM ITR 5-lug front wheel hubs use a larger outer splined joint by default using a 36mm axle nut.  RSX Type-S & Type-R axles share the same larger outer spline joint & 36mm nut. So, Type-S/R axles will basically plug ‘n play into these hubs. Swapping of the inner joints is NOT REQUIRED as the axle lengths are perfect for this application (especially with RSX Type-R axles) UPDATE: I’ve found out (through others and a close friend) that using 36mm RSX-S axles unmodified w/36mm 5 lugged swapped EG/EK/DC2’s doesn’t always work for some. Especially with EK’s using EKK2 Hasport K-swap mount kit and even DC2’s with an EGK1 swap mount kit. This happened with a close friend of mine. The result is the Type-S passenger side axle falls short by an inch or so. The fix for this is switching over to an unmodified 06-11 Civic Si / K20Z3 passenger side axle and retaining the Type-S driver side axle. Turns out the Z3 passenger side axle is the perfect length for 36mm 5-lug users. You don’t want to use a Z3 driver side axle as it is too long and will likely bind. So retain your Type-S driver side axle!

Alternate ‘Hybrid’ and Aftermarket Axle Scenarios

  • Type-S axles w/B-series 32mm outboard joints (4 Lug) Some are forced into this scenario for lack of parts or finding RSX Base model axles. This setup consist of using Type-S inner joints and axle shafts but using 94-01 Integra or 92-00 Civic SiR (B-series) outer joints in order to get the 32mm axle spline use for vehicles with 4×100 wheel hubs. I’ve tried this scenario before and I found it works perfectly fine for street use (and possibly drag race use) but will fail big time for road racing conditions. Binding occurs within the outer joint creating friction. This friction eventually boils the axle grease and creates air within the axle boot, ballooning the axle boot to the point of almost popping! Now, the axle place that I had put these together for me, might have used 90-93 integra outer joints rather than 94-01 integra outer joints. So, I’m not going to fully throw this axle setup under the bus. So, if you go this route make sure you use 94-01 integra outer axle joints! Otherwise stick with RSX base model axles from the get go.
  • EP3 Civic Si Axle Use The 02-05 EP3 civic Si axles are almost identical to RSX base axles in relation to being “32mm axles”. The length is where the difference is, mainly with the passenger side axle. An 02-03 EP3 Civic Si passenger side axle is way too short for use on a K-swapped legacy chassis in its current form. In fact, I think its the shortest factory K-series axle Honda makes. I know this from personal experience.  With an 02-03 EP3 passenger axle installed on a K-swapped EG, the inner boot is noticeably stretched out (and should instantly concern you) and you can visually see a portion of the tripod bearing(s) pushing on the inner boot from coming out of the inboard joint. Lets just say a spirited freeway on ramp pull made a mess under my hood due to this axle splitting apart. However, the EP3 driver side axle is perfectly fine to use as-is unswapped. Just stay away from using the passenger side 02-03 EP3 axle unless you need a shorter axle for a specific reason.  Go 04-05 EP3 Si axle instead. It’s only usable as a donor for its inner + outer joint parts or swapping a RSX base shaft over to it and then disregarding the EP3 shaft. You could possibly re-purpose the EP3 passenger side shaft for driver side use.
  • Hasport EGKAX Axles If you want to go aftermarket axles, these are the ones to get. Brian@Karcepts informed me these are the best aftermarket axles he’s used outside of the OEM axle setup and have held up great for him (he autocrosses btw). Hasport has made these the perfect length as well, so no matter how high or low your car is, the length of these axles will do the job.
  • Stage 1234878654785&#^@# Axles Sorry to disappoint, but I have zero experience with the aftermarket stages 1-5000 axles. OEM axles can handle up to about 350whp which is absolutely fine for me as I’m barely crackin’ 228whp vtack to the tire. If I get more information on higher horsepower axle applications I will definitely update this section.