PRODUCT DETAILS
Driveshaft Shop 1000HP Axle & Hub Kit - 2006-2011 Honda Civic Si (510535)
The Level 5.9 was the go-to high horsepower import axle for over twenty years. This replaces it, and the numbers tell you why. Where the 5.9 was rated at 850 horsepower, this handles well over 1,000 wheel horsepower on the factory 27-spline differential. Complete kit with axles, hubs, and extended studs, built for hardcore race cars and street cars making power that used to require a driveshaft conversation.
What Changed From The 5.9
Worth knowing if you've run the previous generation, because this isn't a minor revision.
Modular two-piece outer CV. Driveshaft Shop's proven modular design replaces the previous single-piece approach, using a 4340 CV housing with a 300M splined wheel stub. That combination gives you the strength where it's needed with low wear properties and a longer lifespan.
Larger diameter splined axle bar. Increasing the spline diameter on the 300M bars improves torsional strength, which is how axles actually fail. Twist rather than bend, and more material through the splined section is what handles it.
Rating went from 850 to over 1,000 whp. That's the practical outcome of both changes together, and it's a meaningful step for a car that had outgrown the old ceiling.
Your Old 5.9 Hubs Won't Work
Important if you're upgrading rather than starting fresh.
This kit will not work with previous generation Level 5.9 wheel hubs. The hub design changed alongside the axle, which is why hubs are included in the kit rather than sold separately.
So if you're stepping up from a 5.9 setup, plan on replacing both. The hubs in this box are what these axles were designed around.
300M Throughout
The material is why the rating exists.
300M is a high-strength alloy used where failure isn't an acceptable outcome, and Driveshaft Shop uses it for both the axle bars and the splined wheel stub. The CV housing is 4340 chromoly in their modular design.
On a front-drive car putting four-digit power through the wheels while also steering, that combination is what stands between you and a very expensive afternoon.
Who This Is Actually For
Being straight, because this is a serious purchase.
Driveshaft Shop built this for the hardcore racer and for high-powered street cars that occasionally see track duty. That's a specific customer: someone making 900 to 1,000 wheel horsepower who has already broken things and knows exactly why they're here.
If your Si is stock or lightly modified, this is far more axle than the application needs and Driveshaft Shop's lower tiers will serve you better. If you're in the power range this was designed around, it's the current answer.
What's In The Kit
- (2) Axles
- (2) Hubs
- (10) Extended wheel studs
Backed by a one year warranty.
Non-Refundable After Installation
Worth stating clearly. Once these are installed they can't be returned, which is standard for driveline components at this level but worth knowing before you commit.
Confirm your application and your power level before ordering rather than after.
Check Your Range Of Motion After Install
Once fitted, cycle the suspension through full travel and turn to full lock both directions. You're checking that the inner joint isn't bottoming out at compression or over-extending at droop, and that everything clears through the steering range.
On a car making this much power, finding a clearance problem in the garage is considerably better than finding it on a pass.
Fitment
2006-2011 Honda Civic Si (8th generation)
Part number 510535. For use with the OEM-sized 27-spline differential. Not compatible with previous generation Level 5.9 wheel hubs.
Who Should Run These
This is for the 8th gen Si build that's genuinely fast and has already found the limit of what lesser axles will take. Nine hundred to a thousand wheel horsepower, drag or competition use, and a car where a broken axle ends more than your weekend. It's the current generation of a design that's been proving itself for two decades. Confirm your setup, fit the hubs that come with it, and stop worrying about axles.
Fits: 2006-2011 Honda Civic Si with OEM 27-spline differential. Part number: 510535. Rating: over 1,000 wheel horsepower. Materials: 300M axle bars and splined wheel stub, 4340 chromoly modular CV housing. Includes: two axles, two hubs, ten extended wheel studs. Not compatible with: previous generation Level 5.9 wheel hubs. Warranty: 1 year. Note: non-refundable after installation.
2006-2011 Honda Civic Si Coupe
2007-2011 Honda Civic Si Sedan