Rumbling diff - how to solve?

[FlashBastd]

I have a noisey diff on my low mileage 318i auto - I believe this is a common prob, but what is the best solution? Rebuild, replace, how much?

Sorry if this has been asked a million times.

[cliffybabe]

Make sure the fluid level is ok first off.

If that doesnt solve it im sure u will be able to pick up a new diff off here cheap enough

[Ziggy]

When does it make the noise? At what speed / load etc? What makes you think it's the diff?

If it is the diff, replacing it with a second hand unit'll definately be the most cost effective way to go.

[FlashBastd]

It tends to rumble on a balanced throttle at motorway speeds.

It has weeped from the front seal, but we keep the fluid topped up, and have put some seal treatment in there.

What troubles me is that our car has only done 77k, so the chances of getting a diff from a lower mileage car are pretty slim!

Is this common, or are we just unlucky?

[E30BeemerLad]

common problem, but defo more cost effective to get another diff for Ԛ£50 and bolt that up, you would be looking at least Ԛ£50+ for the parts + labour to rebuild what you have.

Sure it's the diff and not the prop centre bearing? worth jacking the rear up and turning the wheels to defo confirm the diff is the culprit

[FlashBastd]

Thank you all for your quick replies.

Labour for easy stuff isn't too much of a prob as a relative has a small garage who do my servicing and can do most things, but rebuilding diffs is perhaps a bit much for them. In any case, the car is there at the moment, so I will ask them to confirm that it is the diff.

Assuming it is the diff, what concens me is the likelihood of buying another knackered one.

Also, when I made some enquiries earlier this year, I was struggling to find one near to me, and shipping looked like costing more than the diff!

[FlashBastd]

Just spoken to the tech working on the car, and the prob is the diff.

Bugger!

[E30BeemerLad]

try some of the members on here who are regularly busting cars like jonb or pacerpete

alternatively your relative with the garage must know who in the area does diffs, they could probably get the job done a lot cheaper by approaching the relevant company as another trade outift rather than you as a private joe

[cliffybabe]

I got a diff of a felow zoner and its wicked

[SPADGE]

If its 'rumbling' then the chances are it has a worn CWP and so won't be worth trying to fix it.
Mileage isn't really relevant its the way its been treated and serviced that will have a bigger bearing on its condition. For instance if its launched from a standstill from the lights a lot this will wear the cwp a lot quicker than if its just driven on the motorway all day by a vicar lol! Your best bet is to source one with the correct ratio from an Auto as it can't have been abused as much.
I may have one for you but i'm the other end of the country if you have no joy elsewhere give me a call on 07718 901737
Cheers Spadge..

[kevo]

hiya mate i've got a 4.1 ratio small case diff you can have for Ԛ£20 if you like nice an cheap came off my last car and is rumble free.
kev

[FlashBastd]

Thanks guys, I may have found one with the correct ratio at a good price. If it doesn't work out though I will certainly be calling Spadge.

Kevo, I think your diff would slow my accelleration more than it's already steady rate! Thanks though!

[dodgydodger]

another way is to crush up a banna and put it in, works a treat! works with gear boxes too... verry common scam when selling a car at auction!

[Brianmoooore]

Rumbling diff is not common at all. Very unlikely to buy another like this.
Plenty of whining or hissing diffs around though.

[FlashBastd]

Perhaps I meant whining then...

[Brianmoooore]

Mildly whining diffs can go on happily for tens of thousands of miles. The one on my wife's touring whined for about 50,000 miles before I changed it shortly after it suddenly became louder.

[Speedtouch]

Sawdust used to be an old trick too...(must admit, it didn't make much difference on my old Minor 1000 Traveller's diff though).