[Animal7]

So a trip to Bristol ended up with my 2016 335d (Avon Tuning remap 360bhp) Touring being brought back to Surrey on a low loader. My initial hunch proved correct and my local specialist confirmed a diff failure with metal particles floating around in the fluid. Cue a new diff - £2.2k with fitting. Ouch. I want to figure out what failed (car had recently had a replacement rear pinion seal which may be completely unrelated), by maybe getting someone to take it apart. I'm in SW Surrey. Any ideas who might be able to do that for me? Thanks

[ian332isport]

These guys rebuilt the diff in my e30 many years ago, and it's still working fine.

https://www.hardyengineering.co.uk/

[StuieUK45]

u saying u had car tuned at Avon, then on way home it broke down and u got low loader home, or broke down whilst tuning and had low loader take u home ?

Daft question, what were the symptons of diff failure ? (to keep an eye on things myself)

[MY340i]

root cause diagnostics I suspect will be pricey

[Kal101]

Best (most cost effective) would be , if you’ve a friend / contact who likes mechanical stuff that may be willing to take it apart on a hobby basis.

Otherwise you’ll be paying labour etc and I imagine the costs will soon mount up. It all depends on how curious you are and whether you think a third party may be liable and you’re looking to recoup costs.

Purely out of curiosity did you consider upgrading to a limited slip diff , generally I look at these type on incidents as an excuse to upgrade.

[Animal7]

Sorry, the Avon tuning piece was done 3 years ago, so nothing to do with this breakdown. Just a coincidence with the Bristol connection....😀

[Animal7]

I must admit I didn't think of upgrading the diff, just wanted the car back on the road asap tbh. Have an advanced driving test coming up imminently so needed it sorted...👍

[Kal101]

Originally Posted by Animal7

I must admit I didn't think of upgrading the diff, just wanted the car back on the road asap tbh. Have an advanced driving test coming up imminently so needed it sorted...👍

Fair enough - Good luck with the test

[Leeg1633]

Originally Posted by Animal7

I must admit I didn't think of upgrading the diff, just wanted the car back on the road asap tbh. Have an advanced driving test coming up imminently so needed it sorted...👍

Jus curious, what's the advanced driving test for?

[Watsey]

Originally Posted by Animal7

So a trip to Bristol ended up with my 2016 335d (Avon Tuning remap 360bhp) Touring being brought back to Surrey on a low loader. My initial hunch proved correct and my local specialist confirmed a diff failure with metal particles floating around in the fluid. Cue a new diff - £2.2k with fitting. Ouch. I want to figure out what failed (car had recently had a replacement rear pinion seal which may be completely unrelated), by maybe getting someone to take it apart. I'm in SW Surrey. Any ideas who might be able to do that for me? Thanks

£2.2k for a rear diff, non-LSD, seems like a lot of money. Did you get a breakdown of the costs ?

[Animal7]

Yup, BMW part is something like £2,070 and a couple of hours to fit. Advanced test is the IAM. Have actually found the process quite useful although at times a bit pedantic.

[TiredGeek]

At that sort of money for an open diff I'd be tempted to go for Quaife from Birds

https://www.birdsauto.com/quaife/sea...54361&mi=335dx

[Watsey]

Originally Posted by TiredGeek

At that sort of money for an open diff I'd be tempted to go for Quaife from Birds

https://www.birdsauto.com/quaife/sea...54361&mi=335dx

Exactly...

[moppity]

I had a Quaife LSD from Birds late last year for £2k — it's superb. I'd spend the money on that over the stock any day!

[martin10chk]

Originally Posted by TiredGeek

At that sort of money for an open diff I'd be tempted to go for Quaife from Birds

https://www.birdsauto.com/quaife/sea...54361&mi=335dx

But I think you need a serviceable diff to exchange with them don't you?

[danb1979]

Originally Posted by Animal7

Yup, BMW part is something like £2,070 and a couple of hours to fit. Advanced test is the IAM. Have actually found the process quite useful although at times a bit pedantic.

Yup; agree.. But it makes you look at things a lot earlier; makes you drive more cautiously and better at guestimating what the other knobbers are going to do

[TiredGeek]

Originally Posted by martin10chk

But I think you need a serviceable diff to exchange with them don't you?

Nope, they have a price for exchange diff and a price for outright purchase

exchange is £1679 fitted ex vat, outright is £1998 fitted ex vat.

That link I posted takes you straight there
For some weird reason they don't show anything for a 335d F31 but a 335d F30 is the same running gear afaik, probably just an oversight on their website

[alpinafan]

I have a diff that I have just taken off my 440iGC, only done 20k as I fitted an M LSD diff. Don't know whether it will fit.

[Pobsey]

Cotswolds BMW are doing the M diff for £1600 pick up
Think it’s a Facebook offer

[Animal7]

Have a guess what? The replacement diff has failed after 8 months and is being replaced by BMW under warranty.....

[Kal101]

Originally Posted by Animal7

Have a guess what? The replacement diff has failed after 8 months and is being replaced by BMW under warranty.....

Bloody hell - that bad luck or is something in your drive train eating them ??

[PG325]

Originally Posted by Animal7

Have a guess what? The replacement diff has failed after 8 months and is being replaced by BMW under warranty.....

Do BMW know you've modified the power output of your car, surely they wouldn't guarantee a diff if you're putting more than the standard power through it.

I'm pretty sure they would wriggle and void a warranty if they could prove this.