We make gearboxes and diffs stronger. Precision machining and setup, advanced processes including shot peening and isotropic super-finishing (ISF), and in-depth know-how lead to the strongest, most efficient drivetrains in Australia.



If you’re confident on the tools and want to undertake a transmission, diff or transfer case rebuild yourself, Neat Gearboxes can still provide our core services to help you do the best possible job. Just send us your gears, splined shafts, shift rails, shift ends, shifter barrels and forks (if they're steel) and we’ll put them through our set of unique processes.

Our Peen and Polish package includes all of the following*:

  • Chemical clean gears and shafts
  • Check shaft run-out
  • Crack test components
  • Demagnetise components
  • Shot peen gears and splines to SAE J2441 standards
  • Isotropic Super Finish (ISF) components
  • Lightly oil for corrosion protection
  • Package for shipping

*New/replacement parts including bearings, seals, gears and synchroniser assemblies are at additional cost


3 speed: $575
4 speed: $630
5 speed: $685
6 speed: $735
Crown wheel & pinion: $370
Diff spider gears: $0*
Front/centre crown wheel^: $110

And don’t forget, we have a large range of stock and can source hard-to-find parts. We can also offer professional advice on the suitability of your second-hand parts as part of our service.

*spider gears are processed for free in the context of a gearbox or crown wheel & pinion package

^crown wheel must already be removed from differential. This charge applies to transaxles - where the final drive is internal to the gearbox.


Ideal for classic restorations and dirt bike/quad applications, where you want to improve shifting and reduce heat generated by the gear set, while improving gear fatigue resistance - a great low cost option. Simply send us all your disassembled gears, shafts, shifter rails, forks and shift barrel.

This is also a fantastic option when undertaking a differential rebuild - your crown wheel and pinion will be quieter, stronger and produce less heat after being ISF processed by Neat Gearboxes. Includes the following:

  • Hot tank/cold dip components
  • Isotropic Super-Finish (ISF) components
  • Lightly oil for corrosion protection
  • Package for shipping


Complete gear set: $400
Crown wheel and pinion: $200



The Evo transfer cases and diffs are our specialty. We know them back-to front: you won't find a more experienced and particular builder in Australia.

  • Genuine / OEM pinion bearings, carrier bearings seals, O-rings and shims
  • Strip and thorough inspection
  • Chemical clean gears
  • Crack test gears
  • Demagnetise gears
  • Shot peen gears using SAE J2441 guidelines
  • Isotropic Superfinish (ISF) gears
  • Final chemical cleaning of components
  • Set mesh pattern, backlash and preload to custom specs
  • Reassemble to factory fastener torque settings
  • Package ready for shipping


Mitsubishi Evo 4-6 transfer case $2,249*
Mitsubishi Evo 4-6 transfer case (with new Brena Corse gear set) $4,599*
Mitsubishi Evo 4-6 transfer case (with new Brena Corse gear set upgraded to CT9A splines and billet extension housing) $5,999*
Mitsubishi Evo 7-9 transfer case $2,449
Mitsubishi Evo 7-9 transfer case (with new gear set) $3,999
Mitsubishi Evo 7-9 transfer case (with new Brena Corse DLC gear set) $4,749
Mitsubishi Evo 7-9 transfer case (billet housings) FROM $10,900 depending on models and options
Mitsubishi Evo X transfer case $2,499
Mitsubishi Evo X transfer case (with new Brena Corse DLC gear set) $4,749
Mitsubishi Evo 4-X AYC rear diff $2,239
Mitsubishi Evo 4-X AYC rear diff (with new Brena Corse gear set) $4,749
Mitsubishi Evo 4-X RS rear diff $1,749^
Mitsubishi Evo 4-X RS rear diff (with new Brena Corse gear set) $4,239^

*Includes installing and thread locking new screws in front LSD unit ^Includes LSD plate shuffle where applicable/necessary


Each of these rebuilds are a no short-cut, ground up build of the entire GR6 unit. No stone is left unturned. All builds include the following, which also forms the basis of the NEAT600 (capable of up to 600hp):

  • Crack tested and ISF micropolished gears
  • Built clutch with correct clearances set
  • Mechanical circlip for front drive gear (Dodson)
  • Upgraded selector sleeves x 4 (Dodson)
  • ETS overhaul with ball retainer, fluid and lock nut
  • Valve body overhaul (shifter and oil distribution)
  • Valve body basket filter kit
  • TSB clips
  • 4 x solenoids
  • 3 x line pressure sensors and heat shield
  • Pan filter and pan gasket
  • Re-usable line filter (Dodson)
  • Amsoil DCT fluid (fill)

Additionally, the NEAT800 (capable of up to 800hp) includes:

  • Albins heavy duty 1st gear kit with locknut retention
  • SuperStock 7 plate clutch (Dodson)
  • Forged inner A and B baskets (Dodson)

Additionally, the NEAT1100 (capable of up to 1100hp) includes:

  • Albins heavy duty 1-6 gear kit with locknut retention
  • SuperStock 8 plate clutch (Dodson)
  • Forged inner A and B baskets (Dodson)
  • Billet mainshaft thrust plate (Dodson)

Additionally, the NEAT1200+ (capable of over 1200hp depending on clutch setup) includes:

  • Albins Gen II extreme duty 1-6 gear kit
  • Albins billet selector forks
  • Albins billet output shaft with lock nut retention
  • Albins billet mid housing
  • Albins billet front transfer gears
  • Albins billet rear transfer gears
  • Billet mainshaft thrust plate (Dodson)
  • Clutch of your choice at additional cost


NEAT600 GR6: $11,499
NEAT800 GR6: $18,799
NEAT1100 GR6: $28,599
NEAT1200+ GR6: $43,999 + CLUTCH



Our Compete Neat Gearbox rebuild package markedly improves the strength of your standard gearbox. We offer technology, service and attention to detail that others can’t, bundled into a potent package that offers incredible value for money. This package includes all of the following:

  • Genuine or OEM bearings, seals, snap rings and shims*
  • Initial chemical cleaning
  • Strip, press apart gear sets and thorough inspection
  • Check shaft run-out
  • Chemical clean gears and shafts
  • Crack test components
  • Demagnetise components
  • Shot peen gears and splines using SAE J2441 guidelines
  • Isotropic Superfinish (ISF) internal components
  • Final chemical cleaning
  • Assemble to specifications, set bearing preloads/clearances
  • Package ready for shipping

*see our products section for prices on other items such as synchroniser rings, sleeves, gears, final drive sets, shift forks and drain plugs. These items are all at additional cost.


Ford Mustang MT82 6-speed: $4,349
Ford Ranger MT82 6-speed: $4,349
Ford Focus RS / ST 6-speed: $3,499
Mitsubishi Evo 4-8 5-speed: $3,149
Mitsubishi Evo 8-9 6-speed: $3,599
Mitsubishi Evo X 5-speed: $3,999*
Honda B: $2,649
Honda K: $2,599
Honda S2000: $3,299
Audi R8 V10 Graziano 6-speed: $12,849
Subaru BRZ 6-speed: $3,499^
Nissan SR20/RB20 5-speed: $2,699
Nissan SR20 S15 6-speed: $3,499^
Nissan Skyline R34 GTR 6-speed V160 Getrag: $3,799
Mazda MX-5 / RX-8 (series 1) 6-speed: $3,499^
Mazda RX7 (series 4-7) 5-speed: $2,749
Lamborghini Gallardo Graziano 6-speed: $12,849
Toyota Supra R154: $2,699
Toyota Supra 6-speed V160/V161 Getrag: $3,799
Toyota 86 6-speed: $3,499^

*Includes centre differential pin modification

^Includes countershaft "C-clip" modification

For gearboxes not listed, Contact us to discuss. we are constantly working to grow this list.



The strongest diff solution for the S2000 or MX5 / Miata. Capable of power levels 400Kw+

  • Billet bearing caps custom machined to housing
  • ARP bearing cap bolts
  • OEM pinion and carrier bearings, seals, snap rings, fasteners and shims 
  • Initial chemical cleaning
  • Strip and thorough inspection
  • Bead blast housing and rear aluminium cover
  • Crack test gears*
  • Demagnetise gears
  • Shot peen gears using SAE J2441 guidelines
  • Isotropic Superfinish (ISF) gears
  • Custom machine solid pinion collar (crush tube delete)
  • Apply mat primer to cast iron housing
  • Final chemical cleaning of components
  • Set mesh pattern, backlash and bearing preload to custom specs
  • Reassemble to factory torque settings
  • Package ready for shipping

*only when re-using gears


Use original/supplied final drive set: $2,800
With new 4.1:1 gear set: $3,990
With new 4.44:1 gear set): $3,990
With new 4.77:1 gear set: $3,650




Neat Gearboxes are proud to be an Authorised Australian Distributor of Dimple® Magnetic Drain Plugs. 

Made in the USA, these extremely high quality plugs carry a lifetime warranty and use the strongest and most effective neodymium magnets in the world, keeping your gearbox and engine free of harmful ferrous contaminants.

We hold Dimple® plugs for almost any gearbox, transfer case, differential and engine drain plug available in Australia, including motorcycles. You can also use these on the fill plugs on gearboxes, transfer cases and differentials. Please contact us to confirm the correct size for your application.

Use for:

  • Gearbox drain plug
  • Gearbox fill plug
  • Differential drain plug
  • Differential fill plug
  • Engine drain plug
  • Transfer case drain plug
  • Transfer case fill plug


Prices are the same for all models regardless of the size and application.

1 plug: $59
Additional plugs: $55



High quality rebuild component kits pieced together by us to make it easy for you or your mechanic to rebuild these diffs and gearboxes. Here's a list of what you get:

Mitsubishi Evo 4-9 5-speed:

  • input bearing front (factory updated for earlier models)
  • input bearing rear
  • counter bearing front
  • counter bearing rear
  • input shaft seal
  • front diff seal

In addition, the Evo Master Kit includes:

  • 1st, 2nd, 3rd, 4th, 5th uprated carbon-lined synchroniser rings for improved high-RPM shifting
  • 1-2, 3-4 and 5-R sleeves (sliders)
  • 2 x centre differential bearings

Honda B/K/D:

  • input bearing front
  • input bearing rear
  • counter bearing front
  • counter bearing centre
  • counter bearing rear
  • 2 x diff bearings
  • counter rear snap ring
  • input shaft seal
  • selector shaft seal
  • 2 x diff seals
  • countershaft lock nut (B series)

S2000 Basic Differential Kit:

  • pinion bearing front
  • pinion bearing rear
  • pinion seal
  • pinion lock nut
  • crush collar (spacer tube)

In addition, the S2000 Diff Master Kit includes:

  • 2 x side carrier bearings
  • 2 x diff seals


Mitsubishi Evo 4-9 Master Kit: $1,549
Mitsubishi Evo 4-9: $359
Honda B Hydraulic: $399
Honda K: $339
S2000 Diff Kit: $279
S2000 Diff Master Kit: $479


What is shot peening?

Shot peening is a cold work process, where a workpiece such as a gear is bombarded with small spheres of metal in a controlled environment. When done properly (i.e. to recognised international standards), shot peening adds a uniform compressive layer to the surface of components, and in doing so drastically reduces the possibility of crack formation on a surface.

Shot peening has been proven to increase gear fatigue strength by 30% and in some cases 49%. Neat Gearboxes offers shot peening to SAE J2441 standards as part of our upgrade package, which along with our Isotropic Superfinishing (ISF), seriously improves the fatigue strength of transmission internals.

Check out our short video

What is Isotropic Super-Finishing?

ISF (often referred to as REM, although this is a proprietary name of a similar process) is another industry proven method for improving the fatigue-resistance of gears.

By chemically finishing the surface of metals down to extremely low roughness levels in specialised vibratory finishing machines, the workpiece is left with a non-directional mirror finish. This incredibly uniform surface reduces the likelihood of stress risers (re)occurring. SAE investigations have proven that ISF-treated gears last exponentially longer than those that have not been ISF treated. ISF can be used as a stand-alone process or ideally in conjunction with shot peening of gears.

Due to the very fine surface finish, gear friction is also greatly reduced, meaning your gearbox produces less heat and thus transmits more power to the wheels.

Neat Gearboxes are proud to have specialised ISF machinery in-house.

What causes gears to break?

Without wanting to sound too classroom-ish, what is important to understand when talking about gear strength is that almost without exception gear failure occurs due to fatigue cracks, not an inherent lack of overall strength (ultimate tensile strength). What this means is that improving fatigue strength and preventing cracks should be the main concern, or first step, when upgrading transmissions.

There are many contributing factors to the formation of metal fatigue cracks,  but by far the most common would be stress risers. Stress risers are almost always related to manufacturing process or inherent design weaknesses. They are the “weak link” in what otherwise may be an extremely strong component, and act as a catalyst for crack formation and amplify metal fatigue. Some examples of stress risers include surface disruptions such as casting flashes, forging seams, sharp edges left by machining processes, and other imperfections in the surface of metals from, for example, honing or grinding. Stress risers are more often than not the first point of crack formation and one of the most common reasons for gearbox component failure.

Factory-standard gears can be made remarkably strong by simply eliminating these stress risers. removing sharp edges, deburring forging seams, and polishing imperfections all reduce the likelihood of crack formation. How this is done, though, is extremely important. Some shops "polish" the gears with a die grinder or flapper disc. Based on in-depth research, this has been found to be counterintuitive. While there is occasionally a place for this before other processes, it should never just be left as-is. This is because the very act of grinding and deburring can penetrate the case hardening of the gears, and introduce more stress risers. Where necessary, Neat Gearboxes remove significant forging flashes etc, but only before shot peening and ISF so as to eliminate the possibility of the repair turning into a stress riser itself. The best ways to uniformly ensure that stress risers do not occur are through shot peening and ISF.

Another reason why gears break is when bearings fail. This can happen from misalignment, lack of lubrication, overheating or a combination of all of these factors. This is why we check critical dimensions such as case alignment and shaft runout in the course of our rebuilds. A transmission case that is even slightly misaligned will lead to excessive strain on the gear train and premature failure. We also pay careful attention to lubrication and make improvements to oil feeds and tracks to ensure that your gearbox is adequately lubricated. We can make recommendations in regards to temperature control, including Thermal Dispersant coatings, external oil coolers and pumps. We use and recommend only the best components and fluids.

Finally, Gears can break because of contaminants in the oil. Small metal particles that build up in gearboxes and diffs will eat through the hardened surface over a period of time. Filtration is very rare in standard gearboxes, so that is why we strongly recommend the use of Dimple magnetic drain plugs. We also recommend regular gear oil changes: once a year/20,000km for a street drive vehicle, and shorter intervals for motorsport applications.

Why is heat bad in a gearbox or diff?

Heat is a product of friction between meshing gears and is inevitable in a gearbox or differential. Maintaining heat at stable levels is crucial for a number of reasons. Most importantly, a correctly assembled gearbox or diff has finely adjusted preloads and clearances, which allow for the metal components to expand and contract. These tolerances are critical for normal bearing operation.   If components (and the gear oil) get hotter than they should; that is, hotter than the preloads and clearances allow for, parts may expand to the point where rotating components are no longer sufficiently separated for an oil film to form. This problem is amplified when the heat rises outside of the operating range of the gear oil being used. Metal rubbing against metal in most situations is not a good thing. Too much heat can cause massive damage in a gearbox or diff and this sort of damage will always require major repair and probably replacement of many expensive components, such as bearings, gears, pinions and hubs.   Another critical reason why heat is bad is because it actually robs power. Energy from the engine is transferred through the driveline (gearbox and diff) to the wheels. When the gears intermesh they create heat. That heat requires energy – and takes it from the kinetic energy of your engine. This is part of what is called driveline loss, and is one of the reasons why vehicles have more power at the crankshaft than the wheels.   Excessive heat is a symptom that your driveline is sapping too much power. The only real way to control this is to lower gear friction.

How can I control the temperature of my gearbox or diff?

By Isotropic Super-Finishing (ISF) your gears: Smoother surfaces create less friction. Heat in a gearbox or diff is a product of friction from intermeshing gears. Therefore, smoother gear surfaces create less heat. Simple. ISF is the best and most economical way to reduce heat output from gears, period. Neat Gearboxes offer ISF as one of our core services - nothing makes gears smoother.

By using quality gear oil and changing it regularly: Gear oil plays a crucial role of heat transfer and friction reduction in your gearbox and diff. There is a difference between good oils and bad, and there are different applications for those good oils. Neat recommends a range of quality gear oils for different applications, and recommends changing gear oil every 20,000km/1 year for road use. Vehicles used for racing applications may require gear oil changes much more frequently. Contact us if you are unsure of intervals.

By using a Thermal Dispersant (TD) coating on the housing: This helps the gear oil to transfer heat into the atmosphere via the housing/casing. See “What is Thermal Dispersant (TD) and why do I need it?

If your gearbox or diff is still running too hot after these modifications, the best way to control excessive heat is through using external gear oil coolers. They are a surefire way of preventing the excessive expansion of components in your gearbox, by keeping gear oil temperature within the specified operating range. Neat Gearboxes are currently working on putting together a number of gear oil cooler packages for popular makes.

What should I send you for the Peen and Polish Package?

While items vary between gearboxes, a general list may include:

We only process ferrous materials - we don't peen or ISF brass or aluminium.

How should I package my gears for shipping?

This is crucial. We take a lot of care in packaging customers' gears for return shipping, but we often see them just tossed in a box and sent to us without much thought. Who knows what damage occurs during shipping - it may be the case that chipped teeth and cracks have occurred at this point.

We recommend wrapping everything in multiple layers of newspaper so that the components cannot knock against each other in transit. Then choose a box in which everything fits snugly, and fill up the voids in the box with more scrunched up newspaper or other filling material. Usually the parcel is relatively heavy for its size, so use plenty of masking tape to keep the box from coming apart. Often inserting another layer of cardboard inside the packing box is helpful if it seems a bit flimsy.

While you don't need to thoroughly clean the items (we hot tank and thoroughly clean them as part of the package), it's best not to send them dripping in gear oil, which might seep out into your cardboard box and weaken it, along with annoying the poor courier by stinking out her shiny new van.

How do I purchase parts and services from Neat Gearboxes?

We're moving towards an online purchasing experience, but for now you simply need to contact us and we can forward payment options to you, and inform you of stock availability.

Thank you for your patience while we develop this site.


12 months / unlimited km on parts and labour, strictly limited to the service and parts supplied by Neat Gearboxes. Warranty only applies to normal street use. Competition use voids warranty.

We cannot extend our warranty to our Peen and Polish or ISF Gear Set customers as we have no control over the assembly of the gearbox/diff/transfer case.


Based in Adelaide, South Australia, we strive to make it as easy as possible for interstate and overseas customers to ship their gearbox or components to us for our unique set of services. We can arrange competitive freight services (at cost, no handling charges), and professionally package parts, transmissions or gear sets ready to ship anywhere.


We endeavour to respond to emails within 24 hours, 7 days a week.


(+61) 08 7092 4445 Please call only during business hours.

Address (ship to):

12 Ferry Ave.
Melrose Park 5039

Opening Hours:

Mon-Thur: 8:00am - 4:30pm
Fri: 8:00am - 12:30pm
Sat/Sun: Closed