Eaton M112 Supercharger Rebuild Kits

The Eaton M112 supercharger is a great unit which is fitted to all of the 4.0 and 4.2 litre V8 models of supercharged Jaguar and Range Rover engine. Initially released in the 4.0 XKR and XJR, the supercharger evolved for the 4.2 litre applications with bigger rear bearings and a different rotor coating, and this version was fitted to all 4.2 litre supercharged Jaguars and Range Rovers.

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 – leave it too long and the damage will spread from bearing wear, which is curable, to wear of the rotors and/or main casing, which can be terminal.

Replacing the Bearings & Oil Seals

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 identified and repaired early, our Eaton M112 supercharger rebuild kits, which are £93 for the 4.0 Jaguar models and £142 for Jaguar and Range Rover 4.2 cars (which require more expensive rear bearings), should fix the problem. You will need access to a workshop press but other than that the job is achievable by a competent mechanic.

The kits include front and rear snout bearings, snout oil seal, rear needle roller bearings and the required oil to fill the supercharger after reassembly.

M112 Snout Rebuild Kit

If you’ve identified just a snout bearing needs to be replaced, or that the snout oil seal is leaking, then our £46 Eaton M112 snout rebuild kit may be the most cost-effective way to have your car running as it should. The snout rebuild kit includes front and rear snout bearings, snout oil seal and the required oil to fill the supercharger after reassembly. BUT – if there’s any doubt over the condition of the rear bearings, it would be advisable to change them as well, to avoid a future repeat of the process to remove and refit the supercharger for the sake of two more bearings first time around!

Rotor Pack Bearings

Our M112 supercharger rebuild kits do not include the pair of bearings and seals which live between the rotors and timing gears in the middle of the rotor pack. This is because at manufacture Eaton rolls the casting onto the bearing outer race, permanently sealing them in and meaning the casing has to be fractured to remove those bearings. That said, these are in an oil bath and rarely fail – when we are rebuilding superchargers we do not change the rotor pack bearings. If they do fail, some service providers in the US do offer rebuild of the rotor pack, but the Eaton Corporation themselves consider this to be an unreliable and often unsuccessful route to repair – when the rotor pack is worn out or damaged the only dependable solution is a new rotor pack.

If you want to attempt to rebuild your Eaton M112 rotor pack we can supply you the parts, but caution that it is not a straightforward task.

If your supercharger is too far gone to be recovered, we have stock of fully rebuilt M112 superchargers with brand new Eaton-supplied rotor packs, but this is a last resort!

Preventative oil changes are very important on Eaton superchargers, as the ‘sealed for life’ claim is at best an aspiration, and repairs can be expensive. Although Eaton uses a high quality synthetic aviation turbine oil in its supercharger range, the oil is not indestructible and does oxidize gradually over years of exposure to high working temperatures – especially in the Jaguar and Range Rover applications which are quite hot under the bonnet.

After only 50,000 miles, the original oil can have degraded from the nice clear sample on the left to burnt-smelling brown soup like the right hand sample – not good for protecting the bearings and seals in your Eaton M112 supercharger!

We have a range of oil refill kits which include the required quantity of oil for your Eaton supercharger, with a syringe and tube to aid removing the old oil and filling with the new.