MED S/C CROWN WHEEL & PINION

Name: MED S/C CROWN WHEEL & PINION
Brand: MED Engineering
SKU: MED-3470-FD
Price: 295.0 GBP
Availability: InStock

Part No: MED-3470-FD

£295.00 £245.83 EXC VAT

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Availability: In Stock

Description

Our straight-cut crown wheel and pinion sets are CNC machined from steel billets. We have added an extra 12% to the width of the crown wheel over standard, giving additional surface contact with the pinion to spread the tooth load.

The pinions are now made from aerospace-grade S82 steel, which is 20% tougher than EN36B that most other pinions are machined from.

These suit standard differentials, heavy-duty X-pin differential and also the Quaife ATB or MED helical gear ATB.

Available in the following ratios;

3.47:1

3.75:1

3.88:1

4.066:1

4.2:1

For high performance applications we'd also recommend installing a new set of ARP crown wheel bolts.

Frequently Asked Questions

What's the advantage of an MED straight-cut Mini final drive?

These gears are far stronger than anything produced by the factory, while reducing transmission losses, making a great upgrade for any high performance classic Mini. The pinions gears are machined from aerospace-grade S82 steel, which is 20% tougher than EN36B, while the crownwheel is 12% wider than standard. Transmission losses are reduced by the straight-cut design which eliminates the side-loading of the standard helical-cut gears, freeing up more power to the wheels.

Which ratio final drive do I need?

This is a difficult question to answer for sure, so we have uploaded a comprehensive guide to the various ratios and recommendations on our blog. Please see the following link for more info - https://www.med-engineering.co.uk/blogs/news/which-final-drive-ratio-should-i-run-in-my-classic-mini

Which differentials are these suitable for?

Any standard differential, X-pin, or an LSD that fits to a solid crownwheel. This includes the latest design of Quiafe ATB and MED helical gear differential, part number MED-3610-HD.

Do I need a specific set of bolts?

You can use the standard crownwheel bolts to secure this to the differential, but most customers will upgrade to ARP versions, which are far less prone to stretch. Try part number MED-3502-QB, and torque these to 55lb.ft with some thread lock applied.

What else can be done to strengthen this area of the Mini gearbox?

The MED pinion support housing gives much needed support to the main shaft, which in turn reduces flex under load and much improves longevity of the crownwheel and pinion gears. Search for MED-3701-PS. Frequent oil changes are also a must when it comes to a competition Mini engine/gearbox, which will reduce the tooth wear associated with contaminants in the oil.

Do you make anything shorter than 4.2:1?

In this specific design, no, as the 4.2:1 is about as short as most people need when running either a standard, X-pin or ATB differential. If you'd like to go slightly shorter than 4.2 (better acceleration, reduced top speed), this can be achieved with a set of our 1:1043 drop gears. We do make a 4.5:1 gear set in the hollow style for limited-slip differentials.

Are these louder in use than a standard crownwheel and pinion?

Yes these do produce more mechanical gear whine, however it is not as pronounced as with the straight-cut drop gears. We consider it a good trade-off for the additional strength.