From the workshop
Plain English guides on diff faults, upgrades and what things actually cost, written by the people who do the work.
Latest · Vehicle problems · 21 September 2026 Holden Colorado RG Diff Problems The common fault in Colorado RG rear diffs, why the carrier bearings let go, the warning signs, and why catching it early is the difference between a rebuild and a new gearset. Read the article 
Upgrades · 4 August 2026 Axles: 28, 31 or 35 Spline, How Much Is Enough? Axle spline count is one of the first questions on any Ford 9 inch or Holden build. Here is what the numbers mean and how much strength you actually need. 
Maintenance · 29 July 2026 Water in Your Diff: How It Gets In, What It Destroys, and What It Costs You One of the most destructive problems a differential can have. Here is how water gets past the seals, what it does to the bearings and how to stop it. 
Upgrades · 20 July 2026 Ford 9 Inch Diff Conversion for Holden HQ to WB Fitting a Ford 9 inch under an HQ to WB Holden is one of the most popular conversions we do. Here is what is involved and what to budget for. 
Vehicle problems · 20 July 2026 Isuzu D-Max Diff Failure: Why the Open Carrier Gears Give Out Has your D-Max developed a clunk or grind from the rear end? Here is what usually fails inside the open carrier, and what it takes to fix it properly. 
Guides · 19 July 2026 Repair or Exchange Diff: Which One Do You Need? If your differential is making noise, leaking oil or underperforming, you usually have two options. Here is how we decide which one makes sense. 
Vehicle problems · 15 July 2026 Common Toyota Hilux Differential Problems Hilux diffs are tough, but they are not bulletproof. These are the faults we see most often across the workshop bench, and how to pick them early. 
Vehicle problems · 8 June 2026 Santa Fe Diff Problems and Kia Sorento Diff Faults The Hyundai Santa Fe and Kia Sorento share a rear diff with a well known weak spot. Here is how to catch it early and what your options are. 
Guides · 12 May 2026 Differential Identification: ID Your Axle How to work out which diff you have before you order parts, using the housing shape, cover bolt count, axle tags and ratio stampings. 
LSD · 22 April 2026 Best LSD for Street Use: Helical vs Clutch-Type LSD Helical or clutch type? The two main kinds of limited slip diff behave very differently on the road. Here is how to pick the right one for a street car. 
Upgrades · 10 March 2026 Diff Upgrades NZ: LSDs, Lockers, Gear Ratios and Rebuilds A plain guide to the diff upgrades available in New Zealand, from LSDs and lockers to ratio changes and full rebuilds, and which one suits your vehicle. 
Upgrades · 26 November 2025 Superfinished Differential Gears: Is It Worth It? Superfinishing polishes the gear tooth surface to a mirror finish. It sounds like a gimmick, but there are real benefits for some diffs. 
Ratios · 14 October 2025 Choosing the Right Diff Ratio For Your Wheels and Transmission Bigger tyres, a different gearbox or a towing job can all leave your gearing wrong. Here is how to pick a ratio that puts things back where they should be. 
Upgrades · 30 September 2025 Solid Diff Bushes vs Rubber Diff Bushes Solid bushes sharpen up the rear end, rubber keeps it quiet. Here is how to decide which diff bushes suit your car. 
LSD · 5 August 2025 Choosing the Right LSD or Diff Centre for Your Race Application Drift, circuit, drag or rally? Each discipline asks something different of the diff centre. Here is how we match the LSD to the racing you do. 
Ratios · 17 June 2025 How to Work Out a Diff Ratio Three easy ways to find your diff ratio: count the gear teeth, count the turns, or read the tag. No special tools needed. 
Guides · 18 March 2025 Solid Pinion Bearing Spacers vs Crush Sleeves Both set the pinion bearing preload, but they do it in very different ways. Here is why we use solid spacers on most of our rebuilds. 
Workshop · 11 February 2025 Differential Repair Christchurch What to expect when you bring your vehicle or diff to our Sydenham workshop, from diagnosis through to the 12 month warranty. No articles match that yet. Show all articles or ask us directly.