MED 3-SYNCHRO GEAR KIT

Name: MED 3-SYNCHRO GEAR KIT
Brand: MED Engineering
SKU: MED-3230-3S
Price: 475.0 GBP
Availability: InStock

Part No: MED-3230-3S

£475.00 £395.83 EXC VAT

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Availability: In Stock

Description

Our straight-cut close-ratio three synchromesh gear set is machined on the very latest CNC machinery allowing us to offer a perfect gear tooth form. This kit is intended for early Minis with a three-sync gearbox, with a 'crash gear' on first. As with all of our gear sets, these are made locally in the Midlands so we can keep a constant eye on quality control.

The gear kit is produced from EN36C and case hardened along with molybdenum sprayed baulk ring faces.

Kit contents:

Second gear

Third gear

Laygear

First motion shaft

Gear ratios:

First - 2.573:1

Second - 1.722:1

Third - 1.255:1

Fourth - 1:1

Please see the additional information tab for more detail.

Additional Information

Gearset choice
We offer four different gearsets for the Mini/Metro gearbox, all straight-cut close-ratio types for high performance applications. The Clubman gearset allows you to re-use first and reverse gear from the standard setup, but is only suitable for later rod-change gearboxes.

The Three-synchro gearset is intended for early Minis with three-synchro gearboxes.

Next, the MED Race gearset utilises the same ratios as the original Special Tuning conversions and comes with new a first/reverse gear. It is available for both rod and remote-change gearboxes.

We then have the MED dog-engagement gearset, which does away with the baulkrings for ultimate strength in competition applications. This can be supplied for rod or remote change gearbox housings, with an optional superfinish for even greater durability and reduced friction.

Straight-cut vs helical-cut gears
The design of helical-cut gears, as found in standard gearboxes, leads to increased side (or axial) loadings on the transmission. As power outputs increase, this places greater strain on the transmission casing and bearings, in-turn leading to reduced reliability.

Using straight-cut gears allows us to design a stronger transmission within the standard casing. It also reduces power losses to make the most of the engine's power. We estimate between 5-7bhp can be gained at the wheels by using a straight-cut gearset.

Road suitability
There is a myth that driving with a straight-cut gearbox on the road is hard work. In fact a straight-cut synchromesh gearbox is no different in operation to a regular gearbox, but it will be louder.

Most cars use a straight-cut first/reverse gear; it is the swap to a dog-engagement racing gearset that will affect the drivability of a road car.

Close ratios
Closer ratios give a reduced engine RPM drop when changing up a gear. This keeps the engine within its optimum power band more effectively, resulting in better acceleration through the gears. Fourth gear is still the same 1:1 ratio, but first gear tends to be taller than with a standard gearset, to bring the ratios closer together.

The final drive ratio and wheel size need to be carefully considered to give the best results - contact us if you're unsure.

Frequently Asked Questions

Which cars does this gear set fit?

This is designed for Mk1 Minis with the three-synchro gearbox, from 1959 through to the late 1960s, when the four-synchro design was gradually phased-in across production. These are often known as a 'crash' box, with no synchromesh on first gear, requiring a double de-clutch action to shift from second to first.

Does this give a performance advantage?

Yes, the straight-cut design is more efficient in transmitting power from the engine to the wheels, thanks to reduced side-loading of the gears, which will free up more power. In addition, the close ratios result in a reduced RPM drop as you change up a gear, keeping the engine in its optimum power band as you accelerate through the gears. The Mini will accelerate faster without increasing the engine's power output.

Are these gears louder than standard?

The Mini's standard first gear is straight-cut, just like this set, so it's only second through to fourth that will be different. Our experience is that the straight-cut transfer gears give the loudest gear whine - more so than the main gear set, which is submerged in oil.

Do I need a specific final drive ratio with this gear set?

There's no one-size-fits-all answer to this, however as a general rule we would recommend 3.44:1 for a fast road Mini. First gear is taller than on a standard gear set, so unless your engine has an abundance of low-down torque, getting off the line can be difficult with a final drive any taller than this (3.1, 2.9 etc). For trackday use, shorter gearing should be utilised, typically around 3.9-3.6:1.

Is this gear set for road-going Minis, or only for competition?

This set is perfectly usable on the road, but also quite popular for trackday or road rally Minis. It feels very similar to driving with a standard gearbox, albeit with a taller first gear and closer ratios.