BMW E46 ///M3 & E85/6 Z4 ///M Coupe LS Diff rebuilds
As part of good Maintenance, Differential oil should be replaced around every 100 000km's . In most cases, dealers and manufacturers are now saying that the oil is lifetime oil and that you need not change it but anyone who has worked with oils over periods of heat cycles will tell you that the oil as it ages in the Engine,diff or Gearbox becomes, thinner and Dirty... this soon results in poor lubrication of Moving parts within the diff, causing bearings/Clutch Plates to prematurely fail or start grinding and making other worrying sounds.
If you own a BMW E46 M3 or BMW E86/5 M Coupe , be sure to change your Diff oil every 50 000-100 000km's or every 5 years to ensure that your Differential is well lubricated and doesn't start to wear down the Clutch Plates within the LS Carrier Unit or the bearings within the diff. There are loads of debates online as to which oil is best for the diff and we've tried some of the local oils available (Liqui Moly, Castrol and BMW LS oil with FM Booster) and the oil from BMW, LS Diff oil with Friction Modifiers is the recommended oil for your M Diff. as this oil contains friction Modifiers to reduce wear and protect the moving parts within the Diff.
In most cases where the Diff oil has not been regularly changed, the Clutch Plates and Bearings start to wear causing a Grinding type of sound coming from the rear when you take Tight or sharp left/right turns. If your ///M Car is making the grinding sound then the chances are your vehicle is 10 Years or older without having had a Diff fluid change... at over 100000kms and 10 years of age, the diff will need to be rebuilt with new Seals, Bearings, Outer Races, LS diff Oil to address the grinding sound and ensure that the diff will not fail in the future.
BMW's solution is to replace the entire Diff which will cost you as the customer over R40000.00 excluding Labor as they do not sell Bearings or spares for the diff.. they only supply seals and Oil.
Because of this enormous cost to replace the Diff we at MMS Auto have rebuilt both the M3 and Z4 M Coupe Limited Slip Differentials on our personal vehicles and our customers to address this issue and we offer this service to the Public.
We use the following in our rebuild:
> Imported "TIMKIN" Bearings from the USA as they have very high speed ratings and are a premium quality brand. Perfect for a high performance car which does well over 200km/h!
> Genuine BMW Seals
> Genuine BMW Limited Slip Diff oil with Friction Modifiers
> Only OEM parts are used.
Contact us for Pricing on your Vehicle...
Below are Pics from the E86 Z4 M Coupe Diff Rebuild
1.Here we have the Differential removed from the Car
Diff cover removed.
Checking if all is within Spec before stripping the diff and rebuilding begins
All rebuilt and ready to go back into the ///M Coupe.