BMW 325i Touring Diff E30 1989

[mbrain]

My 325i Touring E30 has a noisy diff, and seems to be getting worse, my questions are:

How much for a replacement?

Where can I get one from?

Could it just be low on oil, or need replacing?

I'm taking it to my local garage on Tuesday, a couple of knowledgeable guys work there.

Many thanks.

[Incitatus]

Depends if it's an LSD or open diff as to cost for replacement. They can go on for years without problem, if you can put up with the noise!

I don't think there's much you can do to it to shut it up though. You can check on ebay or e30zone.co.uk for a replacement, although I have a good open diff in the back of the garage after I swapped mine out for an LSD. If you're going to go to the bother of changing the diff £250-£300 for an LSD is a nice improvement.

[Oi_Oi_Savaloy]

Hi

It all depends on whether it is an open diff or an LSD.

2nd hand open diffs - very cheap. (£30 to £50 ish). You just need to check which ratio you have and go to a breakers or e30zone and buy one.

An LSD is entirely different matter. a non-refurbed one in an awkward ratio will be £200ish. A refurbed big case lsd will be £350 and upwards.

There are 3 ways to check; two are watertight, the third all down to how original the car is.

1) Jack the rear of the car up. spin one wheel. does the other turn? Yes? You have an lsd. I think I'm right in saying the other wheel will actually turn in the opposite direction but turn it most certainly will.
2) Jack car up or put on ramp. read the little (very, very rusty) tag attached to diff (underneath the car!). If it says something like S 3.15 or 3.89 then you have an LSD. The S is a bit away from the numbers and sometimes hard to read. Sometimes the tag is missing though.
3) Check original build sheet. On a touring an lsd would have been an option. It will be on the build sheet or order sheet.

If you have the funds - don't buy an open diff. Go LSD - they really are a very worthwhile upgrade.

Edited by Oi_Oi_Savaloy on Saturday 8th May 20:51

[mbrain]

Thamks for your replies.

I can't see any tag on the base of the diff (I squirmed underneath it!).

She's booked in on Tuesday, so I'll ask the mech at the garage to confirm which it is. There is a small oil leak from the diff, but the oil is very clean though.

Personally, I'm not fussed on an LSD or normal diff.

The diff also locks up up as it should when driving.

Any further advice would be gratefully received!

[mbrain]

Incitatus said:

Depends if it's an LSD or open diff as to cost for replacement. They can go on for years without problem, if you can put up with the noise!

I don't think there's much you can do to it to shut it up though. You can check on ebay or e30zone.co.uk for a replacement, although I have a good open diff in the back of the garage after I swapped mine out for an LSD. If you're going to go to the bother of changing the diff £250-£300 for an LSD is a nice improvement.

Thanks for the offer. Once I get an answer on Tuesday I may be in contact.

I take it there were no issues with it, you just wanted an LSD? Also, would it be a straight swap for mine? 1989 325i auto.

Thanks again.

[agent006]

Change the diff oil before you look at changing the diff. The diff in my track 325 makes the most horrendous noise but has been fine for 20k miles and I don't mind the noise.

Don't get an LSD. If you need one you'll know (you have problems with spinning one wheel and going nowhere). I don't have one on mine and rarely miss it, certainly not enough to justify the cost.

[mbrain]

Looks like it's a wheel bearing, being changed tomorrow.

[Oi_Oi_Savaloy]

Whilst it's on the ramp - get them to look at the bushes too maybe? Just buy BMW ones (rather than polyflex) - will make a big difference to your comfort.

Rhydian