Diff Worry

[Dan318-is]

ok got my new IS friday, when i test drove it there was a wine coming from the centre rear. i was told the prop bearing was replaced an after a couple of minutes it did seem to disapper. However, i picked the car up friday, and especially from cold, there is a horrible whine/f1 style noise coming form the centre/rear and im considerably worried its the diff!

to make matters worse its a 4.10 LSD, like goldust i dont wona chuck it away. so whats the problem? will an oil change do anything?

as i said i dont wona throw it so if it is the diff how much is a rreconditioning going to cost me??

HELP ME!

[ItalianM3]

Maybe the wrong oil has been put in! It is an LSD yes?

I would have thought a rebuild would be around the same price of a second hand unit, around Ԛ£150-200.

Why are these diffs like gold dust?

[Dan318-is]

il change the oil and see. im prepared 2 spend that!

its because it was only an option on the 318is, not many had the option ticked! well glad i found one! so dont wont 2 have 2 bin it and go back to open diff wrongness

[thesaint]

i was told that a rebulid would cost about Ԛ£250, which is better thatn getting a second hand one in my opinion, you never know how nackered the replacment is. A sport LSD went for Ԛ£282 on ebay the other day. People would pay more for yours i would of thought. Hope this helps

[astondg]

My 4.1 LSD cost about GBP 350 I think. That was buying the gear set and required parts (about GBP 230) which were supposed to be left over from a BMW 2L touring car, getting the lapping done and having it all rebuilt to new condition, using Redline motorsport LSD oil (which I am told is very good, and I now know is expensive ), and building it all into my factory diff case/housing (which was an LSD already and I think a large case). The guy that did it said he removed the friction modifier or something and set preload to 90lb. That might give you an idea and I imagine with you already having the 4.1 gear set it would be a lot cheaper.

I still have a whine like you described in the drivetrain but I am fairly sure that it is from the gearbox (it is worse in 1st gear and the gearbox feels like it is getting a bit tired). The diff does chatter a bit though (mostly on light throttle and when I back off sometimes) but the guy told me that is normal for the type of diff it is (a sort of motorsport spec) and it does sound a bit like a race car which is kind of nice .

Aston

[Jhonno]

check the oil in the diff..

[Simon]

I've noticed that LSD equipped cars, always seem to have more diff noise than open diff cars, if it's very loud though, then it's different...

[oze30]

if it sounds like a BTCC 2l bmw.. I'd leave it!! Love that gear whine going up thru the gears!!

(Alan Jones, Tony Longhurst, Steve Soper, Joachim W, etc etc etc)

Hmmmm.....

Love those days!

[astondg]

I think that is more due to the straight cut gears in the gearbox rather than the diff (feel free to correct me ).

Aston

[Brianmoooore]

A slipper diff is no different than an ordinary diff when the car is being driven straight, so if it whines in a straight line, it's not because of non LSD oil.
Whining diffs are fairly common on E30s. My wifes touring had whined for the whole 8 - 9 years she'd had it, untill earlier this year, when the note suddenly changed to a much harsher whine. Still worked OK, but at that point I changed it. Might have gone on OK for another 8 years AFAIK.

[Dan318-is]

the problem is its hard to tell; its extremly loud when cold, the sound pitch increasses rapidly then just cuts out. once the car has been driven for 15 mins it is only very faint whine

my mate seems to think its the propshaft bearing that the whine is coming from but im not so sure

what does it exactly mean when it is whining anyway?

[E30Mark]

Is the whine there all the time?

Or only when you back off the accelerator?

Mine has started to whine when i back off, luckily i have a spare 4.1 diff in the shed ready to go on one of these days (open diff, can't afford a LSD )

[Dan318-is]

you got an lsd on yours at the moment mark

i thinks its only when i accelerate. having said that when im poodling with no music on i can hear a fiant whine!

i mite get the prop bearing looked at first though before i worry myself about the LSD

[E30Mark]

It's a open diff on there, wish the previous owner had ticked the LSD box

[Dan318-is]

it makes such a difference round corners mate its unreal

but once you loose it you really do loose it!!

just hope i dont have to shell 250 to get mine repaired!