Repair or Exchange Diff — Which One Do You Need?
If your differential is making noise, leaking oil, or underperforming, you usually have two options: a repair, or a rebuilt exchange diff. Here’s how to tell which one suits your vehicle, and why we recommend exchange when you need to minimise downtime.
Repair
When your diff needs repairing, we strip it down completely to diagnose and fix the fault. The most common failures we see are:
- Worn bearings
- A worn or damaged crownwheel and pinion
- A worn LSD or open carrier
We fully strip and inspect the diff, so a repair gets your original unit back to correct working order. It does mean your vehicle is off the road while we carry out that work. We generally offer a quick turnaround on most repairs, since we stock most differential parts to suit a wide range of vehicles. Turnaround can depend on part availability for less common models. A repair is also sometimes the only option, since we don’t hold an exchange diff for every model.
Exchange Diff
An exchange diff is a differential we’ve already fully rebuilt and tested, ready to install in place of your original unit. Instead of waiting for us to strip down and rebuild your own diff, you swap it out for a ready-to-go rebuilt unit. Your original core then goes toward the exchange.
Pricing
An exchange diff costs exactly the same as a standard rebuild, so you’re not paying extra for the convenience — you’re simply saving the wait.
If your original diff comes back with failed bearings but the crownwheel and pinion are still reusable, we charge you the same as a standard rebuild. If the crownwheel and pinion aren’t reusable, we charge you the same as a full rebuild — there’s no premium either way.
Our pricing already includes the core charge for the crownwheel and pinion, in case it turns out not to be reusable. Once we receive your old diff back, we check the crownwheel and pinion and refund the core charge if it’s in good enough condition to reuse.
Parts Quality
We build most of our exchange diffs using good-condition OEM used crownwheels and pinions, sourced from other cores that have come in on exchange. A used OEM crownwheel and pinion in good condition often outperforms a new aftermarket one. Aftermarket manufacturers typically produce gear sets in smaller batches, and to a lesser standard than the original manufacturers do.
When Exchange Is the Right Call
This is usually the right option when:
- You need your vehicle back on the road as quickly as possible
- Your original diff has failed too badly to be worth waiting on
- You’d rather have a known, tested unit than wait for us to rebuild your own diff
Because we’ve already built and tested an exchange diff, turnaround is much faster than repairing your original unit, and the cost is the same either way. That combination makes exchange the more practical choice whenever downtime is a priority.
So Which One Do You Need?
Most of the time, an exchange diff is the best option — even if you want to upgrade your diff at the same time. Thanks to our extensive stock, we can generally tailor an exchange unit to your exact needs, whether that’s a ratio change, an LSD upgrade, or a direct replacement. This keeps your vehicle off the road for minimal time. For workshops, it also means we don’t tie up your hoist while you wait for us to repair a diff.
Vehicles We Stock
We currently stock over 80 rebuilt exchange units, covering 20+ different vehicle models. Most commonly:
- Toyota — Hilux, Hiace, Land Cruiser
- Ford — Ranger, Falcon, Courier
- Holden — Colorado, Commodore, Rodeo
- Isuzu — D-Max, Bighorn
- Mazda — Bounty, BT-50, CX-5, CX-9, RX-7 (FC and FD), RX-8
- Nissan — Safari, NV350 Caravan
- Renault — Koleos
- Audi — TT
Where available, we stock multiple ratio options, as well as both LSD and open diff variants, for these models.
For popular 4WD models, we typically stock both front and rear exchange units, not just the rear. Get in touch even if it’s the front diff giving you trouble.
Nationwide Shipping
We’re based in Christchurch, New Zealand, and service the whole country. We offer free return freight nationwide, and we book both legs of freight for you — our freight company automatically picks up your diff, with no courier drop-off needed on your end.
Frequently Asked Questions
Is a rebuilt exchange diff as reliable as a repaired original?
Yes. We fully rebuild and test every exchange diff before it goes out, using new bearings and seals, along with either a new or good-condition OEM crownwheel and pinion. We hold it to the same standard as a diff we’d repair in-house.
How long does an exchange diff take compared to a repair?
An exchange diff is usually the fastest option, since we’ve already built the unit and it’s ready to install. You’re not waiting for us to strip, inspect, and rebuild your own diff. A repair on your original diff can take longer, though we generally offer a quick turnaround given our parts stock.
Do you ship exchange diffs anywhere in New Zealand?
Yes. We’re based in Christchurch but service the whole country, with free return freight and both legs booked for you.
What if my crownwheel and pinion turn out to be reusable after all?
Our exchange pricing includes the core charge for the crownwheel and pinion upfront. Once we receive your old diff back and inspect it, we refund the core charge if the parts are in good enough condition to reuse.
What if you don’t have an exchange diff for my vehicle?
For less common models where we don’t hold exchange stock, we can carry out a full repair on your original diff instead, getting it back to correct spec.
We diagnose every vehicle before recommending an option. In most cases, that means a rebuilt exchange diff tailored to your vehicle — for less common models without exchange stock, a repair gets your original diff back to correct spec instead. Get in touch with our team, and we’ll talk you through the right option for your vehicle.
