Not Your Typical Supercharger?

Just as many OE manufactures do, BMW have created a bespoke supercharger unique to the BMW Mini.  Using Eaton’s very dependable M45 rotor group they have created a supercharger in two variants Gen 1 & Gen 2 depending on year of manufacture.  Both utilise the supercharger shaft to drive the water pump on the opposite end.

Although this is very convenient and necessary to get such a supercharger in the confined space of the BMW Mini, it has also become the backbone of failures on these units.  Premature seal failure leads to oil loss in the PTO (Power-Take-Off) unit, in tern this allows the PTO gears to rapidly wear and eventually fail losing all drive to the water pump leading to a host of over heating issues and supercharger noises.

The added complexity of the PTO makes the Mini M45 a more challenging unit to rebuild than most Eaton types, but for the competent home mechanic or experienced garage it is still achievable.

Repair

Repair of the PTO was usually a scrapping issue with the worn gears not being available from BMW or Eaton.  Repairs have been undertaken by sourcing used good condition gearsets, but these are hard to find with most people opting for the used market risking purchasing a similarly worn blower.  Final choices have been to choose 1 of 2 aftermarket manufacturers of replacement gears at a hefty price tag but NO LONGER.

We at Powerhouse are happy to announce that we can now replace the worn gears in your Mini, as well as all other bearings and seals, for brand new UPRATED GEARS designed and produced to our specification.  To our knowledge we are the only aftermarket company to have kept true to Eaton’s design features by incorporating their custom gear profile designed to match oil viscosity to the high speed of the gears.  We have also upgraded the gears by opting for a wider gear to reduce the load per gear tooth and reduce the risk of total gear wipe-out as seen on some units.

See our shop for pricing of the various bearing, seal and gear components and kits for the Mini Eaton M45 supercharger.

Rebuild Kits

Good though they are, these superchargers can be subject to premature seal or bearing wear, or failure of the drive coupler.  Rattling at idle is the first indication that something is going wrong, usually that a bearing is starting to wear, or that a drive coupler is fractured and failing.  The important thing is to have them repaired when you hear early signs of something being wrong – if they are left rattling too long and the damage will spread from bearing wear, which is curable, to wear of the rotors and/or main casing, which can become bad enough to scrap the supercharger.

Replacing the bearings and oil seals in your supercharger will give it a new lease of life, and your own peace of mind.  As long as issues are not ignored and repaired early, our Eaton M45 supercharger rebuild kits, which start at £142 for the base rebuild kit, will often fix the problem.  You will need access to a workshop press but other than that the job is not beyond the ability of a competent mechanic.

The kits include snout bearings, snout oil seal, rear needle roller bearings and the required oil to fill the supercharger after reassembly. (Please note this does not include parts for the PTO, please see our shop for further options).