[HFM66]

Hi All,

A newbie here so please be gentle...

Had my 07 e91 318i M Sport for a few months now, I've still getting used to the power (or lack of)..
Needs must and a sensible family car required...

Just had it serviced and the advice from my trusted local independent was it needed a new rear axle final drive... and I thought it was a bearing...

Been quoted nearly £1900 fitted etc... is there a better easier option for those of us not that competently minded as not keen to spend 2/3 of the value of the car...

I'd only yesterday changed the glass window switch to finally to be able to lift the glass only...

Thanks,

HFM66

[Sensible_]

Can you give some background? Why does this need changing? What's the cars mileage and what symptoms do you have to suggest this needs replacing???

[HFM66]

Hi,

Its a 2007 318i on 90,000 miles.

There was a noise coming from the rear of the car, it sounded like a wheel bearing was on its way out.

I took it into my BMW Specialist for a service and what I thought was a new wheel bearing, he advised it was the Rear Axle Final Drive that needed replacing.

Thanks,

HFM66

[Sensible_]

Originally Posted by HFM66

Hi,

Its a 2007 318i on 90,000 miles.

There was a noise coming from the rear of the car, it sounded like a wheel bearing was on its way out.

I took it into my BMW Specialist for a service and what I thought was a new wheel bearing, he advised it was the Rear Axle Final Drive that needed replacing.

Thanks,

HFM66

Hmm, can you upload a video of the noise?

To be honest, before replacing the diff it's worth changing the diff oil first to see if that helps. It's a diy job. But wear nose plugs! The stuff stinks.

I've also seen e90's with a constant hum sound diagnosed as a rear diff. When in actual fact it was front wheel bearings. The sound can resonate strangely in the cabin.

[bfleming]

Swapping the differential on these cars is a very easy job. My local friendly mechanic charged me £80 to change it, and I think the replacement cost me £80 from ebay - so £160 all in. There are several ratios available, so make sure you get the same ratio as you currently have.
I swapped mine to change ratios, not because it was worn out.
On the 318i the manual & auto cars have different ratios. Go to realoem.com, put the last 7 digits of your vin in, browse parts, rear axle, rear axle drive. That should show you your diff. Manuals usually have the ratio 1:3.38, autos are usually 1:3.91.
My initial look says these diffs are a lot more expensive than the diesel ones, but I guess they're rarer. You might have to pay up to £400, or £500 fitted. Still cheaper than the main dealer.