Diff rebuild

[Alan W]

My 1999 facelift 2.8 auto with Torsten LSD has always had a little bit of a 'diff-wine' which I only notice at very slow speeds and at around 80mph when the car is at that point where your foot is literally just resting on the accelerator to maintain that speed and you then lift it off (hope that makes sense).

I have read that this is typical specifically of LSD's..

I have also read that it is common within BMW's of the era (both LSD and non LSD variants)..

So my first question is could this whine be caused by anything else in the drive train ie drive shaft couplings?

Secondly, whilst I am happy to live with it, if it gets worse I have found a complete replacement bearing kit @ £150 but wouldn't know where to start.. does anyone know of a company that specialises in rebuilds?

Thanking you..

 

[colb]

Specialist job unless you have some sophisticated measuring tools to set it all up, best left to an expert in my view.
Had a Kia Sorento diff go bad on me and I used a local transmission specialist who did a good job and a lot less than Kia wanted to charge for a new diff.
As my specialist is in Wales its a bit far for you in Kent.
Found these in Kent doing a Google search for diff repairs in Kent
http://www.rrtransmissions.com/#home
Maybe worth asking for a quote?

 

[NZ00Z3]

I found changing the diff oil regularly (every second engine oil change) keeps the noise in check.

Used Redline 75W-90 in both the small case open diff and the medium case clutch LSD and the noise reduced to acceptable levels.

Also, having a Poly sub-frame of diff mount will increase the transmission (volume) of the diff whine into the car.

 

[Brian H]

Automac can rebuild diffs, if it get to that stage give them a call and I'm sure they can help out.

 

[Lee]

I tired to do mine on my M (clutch plated diff) and although the bits were sub £50 no one would give me the preload setting for the pinion bearing. So i had to cough up £380 for a full rebuild. BK transmissions

 

[Dobiwallah]

My 1999 facelift 2.8 auto with Torsten LSD has always had a little bit of a 'diff-wine' which I only notice at very slow speeds and at around 80mph when the car is at that point where your foot is literally just resting on the accelerator to maintain that speed and you then lift it off (hope that makes sense).

I have read that this is typical specifically of LSD's..

I have also read that it is common within BMW's of the era (both LSD and non LSD variants)..

So my first question is could this whine be caused by anything else in the drive train ie drive shaft couplings?

Secondly, whilst I am happy to live with it, if it gets worse I have found a complete replacement bearing kit @ £150 but wouldn't know where to start.. does anyone know of a company that specialises in rebuilds?

Thanking you..

Mine has the same behaviour, got a bit worse after the diff poly bush swap. I can hear it quite good when the auto gearbox is switching back to first gear. I consider it just as facts of life. You almost sitting on the top of the diff with your bottom.

 

[Alan W]

Mine has the same behaviour, got a bit worse after the diff poly bush swap. I can hear it quite good when the auto gearbox is switching back to first gear. I consider it just as facts of life. You almost sitting on the top of the diff with your bottom.

Just got quote for £400 plus vat for rebuild if l remove diff myself and drop it off.. that's for new bearings and seals.. If there's any issues with crown wheel or pinion is worn that's extra..

I think youre right @Dobiwallah.. live with it.. when l take car cover off sometimes l put it in the boot and that reduces the noise so one answer could be an extra layer of carpet and turn the radio up..

Don't get me wrong.. its not bad by any means.. its just that once you notice something you latch on to it.. like when you stay at a friends house and just as you start to fall asleep you notice that clock ticking lol!!!

 

[Dobiwallah]

Just got quote for £400 plus vat for rebuild if l remove diff myself and drop it off.. that's for new bearings and seals.. If there's any issues with crown wheel or pinion is worn that's extra..

I think youre right @Dobiwallah.. live with it.. when l take car cover off sometimes l put it in the boot and that reduces the noise so one answer could be an extra layer of carpet and turn the radio up..

Don't get me wrong.. its not bad by any means.. its just that once you notice something you latch on to it.. like when you stay at a friends house and just as you start to fall asleep you notice that clock ticking lol!!!

I bought mine Z with 30.000km and it had the noise then already. You might spend £400 plus vat and end up with the same noise...

The New Zealand roads are so noisy, thats why I dont hear it. There is only one piece of 30km 4 lane highway near Auckland which is really quiet, that's the only place I can hear it when I my foot is literally just resting on the accelerator to maintain that speed.

 

[Dino D]

It's along time since driving a brand new Z but I rember it feeling much more 'agricultural' in a good way than a TT. Can't rember if I could here the diff but do remember that the diff was audible in e30's and even my e46 if you were sat in the back seat.
Even the e60 M5 would make thump from the diff when sat in the back and giving it full beans (that might be the super agressive SMG in play there but you could here the diff 'working' even on that).

A bit of whine to me reminds me I'm driving a proper car and adds to that classic car feel.
It's the last non M BMW to ever have an LSD fitted. Whack a poly diff mount bush in there for a bit of extra diff whine and celebrate the fact you have one of the last proper BMW's!

Fluid changes help for sure.

 

[Dino D]

Ps to deaden sound and add some refinement you can add sound deadening material in two places:
Under the carpet behind the roll hoops
Under the carpets throughout the boot.

On the flip side you may dull you exhaust note.
I have the opposite - no carpets in boot and behind roll hoops and exhaust is much clearer but can also hear much more road noise as a result.

 

[Dino D]

Pps did they really change the 2.8 diff to Torsen from the original clutch pack for the facelift?

Or did the autos all have Torsen from the original through to facelift.

 

[Alan W]

Dino.. that is so true.. all the little quirks do remind you that this is a 'classic look and feel' car built around a modern very powerful silky smooth torquey 6 pot.. I always wanted a TR6 and this is probably the nearest I will ever get, but like I said its not bad noise by any means... and knowing that its a LSD sat just behind my arse is kinda cool..

I once won a competition.. an Aston Martin Day at Goodwood and spent the morning driving DB7's around the circuit 'pedal to the metal'. They also gave us a spin (as passengers) in a couple of top end AM's on of which was a V8 Vantage Volante which had a manual box with straight cut gears... and boy was that gearbox noisy!

 

[Alan W]

Pps did they really change the 2.8 diff to Torsen from the original clutch pack for the facelift?

Or did the autos all have Torsen from the original through to facelift.

Not sure Dino.. mine was one of the first facelifts (March 1999) and because the waiting lists were long it was ordered into Germany as a RHD and then imported into the UK.. whether the LSD was a standard 'facelift upgrade' or the buyer paid for it as an upgrade I will never know.. not sure of what cars had what type of LSD's but maybe someone here will know?

 

[5harp3y]

i think all UK supplied 2.8s came with a LSD

 

[Dino D]

i think all UK supplied 2.8s came with a LSD

Certainly the manuals. Not sure on autos.

I believe all 2.2 and 3.0 also had LSD but Torsen type.