Leaky Diff

DuncanR · 16-11-2009, 03:42 PM

Leaky diff anyone? Whilst hoisting my car up in the air for some less than ordinary shots of it, and indeed to get a good first time look at the underside, I noticed oil over the bottom of the diff housing

.
First impression is that its the front seal, vehicle has now done 61k, just wondered if anyone else had come across this problem. As this wont be covered by warranty, anyone know how much is involved to DIY ? Wondering if its just drop the UJ's, remove prop, dig old seal out with readliy available meat skewer and replace with new ! On the point of checking the level, which would be a big plus right now, is it just a case of filling until it dribbles out of the filler plug hole, or a bit more technical than that? Doing trackday at Bedford this Saturday 21st so need to sort, failing that will strap a couple of sqeezy diff oil bottles to roll cage and a long hose to the filler plug !!

Will Fields · 16-11-2009, 09:17 PM

How much oil is on the bottom of the diff? Is it just a mist that could have accumilated over a period of time??
As for the DIY job the problem you may have is that the pinion has a collapsable spacer betwen the bearings which should really be replaced once the nut is loosened. This spacer is there to set the pinion bearing pre-load.
I have heard that BMW dealers just take the nut off and replace the seal then tighten the nut back up but this is not the correct way of doing it!
The correct procedure is to strip the diff out, change the pinion seal and collapsable spacer and re set the pre load.
To check the oil level the car must be horizontal (on a ramp or all four corners the same hight in the air) then it should just drip out of the filler plug. Dont over fill it or it may pour out of the breather/seals!!
If you want the seal changing in the "proper" manner give me a ring on 01652 648429 (office hrs)
Hope this helps!!!

**shimmy** · 16-11-2009, 09:26 PM

my car had leaky side seals at 60k miles

had BMSport replace all 3 seals and all is still well and diff going strong

(i reckon most fo the failing diffs you see on CSLs are due to loss of fluid at seals)

bromers · 16-11-2009, 10:21 PM

Had mine done under warranty after about 13k miles (2 yrs).

Thorney · 17-11-2009, 08:42 AM

Depends on how much of aleak, a little weeping is fine.

DuncanR · 17-11-2009, 12:29 PM

Thanks for all the input guys, what a fine bunch you all are ! A little nugget of information that has just come to light upon reading the original advert for this car, it had a new diff about 7k ago ! sorry ! Its not pi$$ing out by the look of it, so will monitor it for now, and check level before track day this Saturday. Have attached a pic hopefully !

mattCSLnut · 17-11-2009, 01:36 PM

Quote:

Originally Posted by DuncanR

Thanks for all the input guys, what a fine bunch you all are ! A little nugget of information that has just come to light upon reading the original advert for this car, it had a new diff about 7k ago ! sorry ! Its not pi$$ing out by the look of it, so will monitor it for now, and check level before track day this Saturday. Have attached a pic hopefully !

Yeah, I thought your CSL did have a replacement diff not long ago. If BMW did the work it will be under 2 Year BMW Warranty. Check the date of figment as you might be able to get them to fix it for FREE

_Nathan_ · 17-11-2009, 03:32 PM

I'd have thought it was done by Schirmer as the diff was modified I believe.

DuncanR · 17-11-2009, 04:40 PM

Good call Matt on the 2 year warranty, thanks will investigate further.
I saw Tom Schirmer on Friday, I need to email him on another matter so will ask him, and of course Andrew who will know better than anyone ! mmm modified diff ??? maybe thats what makes the Black ones quicker !

shane@mbtech · 17-11-2009, 10:18 PM

Quote:

Originally Posted by DuncanR

Good call Matt on the 2 year warranty, thanks will investigate further.
I saw Tom Schirmer on Friday, I need to email him on another matter so will ask him, and of course Andrew who will know better than anyone ! mmm modified diff ??? maybe thats what makes the Black ones quicker !

If for instance you had a 2 yr 11 month old csl and the diff was replaced under the 3 yr warranty, and then when the car was 4 yrs old, 13 months later the diff would have no warranty. The warranty would have expired when the cars warranty did at 3 yrs. UNLESS you contributed, even if it was 1p, then and only then would the 2 year guarantee apply.

TBH, check your level ,most diff leaks are caused by over filling. It does not look that bad, clean it off, check/adjust your level then monitor every few k

16-11-2009, 03:42 PM	#1
DuncanR CSL Register Uber-poster! Join Date: Sep 2009 Location: Olney, Bucks Posts: 3,735 Casino cash: $9984	Leaky Diff Leaky diff anyone? Whilst hoisting my car up in the air for some less than ordinary shots of it, and indeed to get a good first time look at the underside, I noticed oil over the bottom of the diff housing. First impression is that its the front seal, vehicle has now done 61k, just wondered if anyone else had come across this problem. As this wont be covered by warranty, anyone know how much is involved to DIY ? Wondering if its just drop the UJ's, remove prop, dig old seal out with readliy available meat skewer and replace with new ! On the point of checking the level, which would be a big plus right now, is it just a case of filling until it dribbles out of the filler plug hole, or a bit more technical than that? Doing trackday at Bedford this Saturday 21st so need to sort, failing that will strap a couple of sqeezy diff oil bottles to roll cage and a long hose to the filler plug !!

17-11-2009, 08:42 AM	#5
Thorney S5 - Full Throttle Join Date: Sep 2007 Posts: 469 Casino cash: $3876	Depends on how much of aleak, a little weeping is fine. __________________ http://www.thorneymotorsport.co.uk

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16-11-2009, 09:17 PM	#2
Will Fields S2 - Picking it up Join Date: Oct 2009 Posts: 37 Casino cash: $893	How much oil is on the bottom of the diff? Is it just a mist that could have accumilated over a period of time?? As for the DIY job the problem you may have is that the pinion has a collapsable spacer betwen the bearings which should really be replaced once the nut is loosened. This spacer is there to set the pinion bearing pre-load. I have heard that BMW dealers just take the nut off and replace the seal then tighten the nut back up but this is not the correct way of doing it! The correct procedure is to strip the diff out, change the pinion seal and collapsable spacer and re set the pre load. To check the oil level the car must be horizontal (on a ramp or all four corners the same hight in the air) then it should just drip out of the filler plug. Dont over fill it or it may pour out of the breather/seals!! If you want the seal changing in the "proper" manner give me a ring on 01652 648429 (office hrs) Hope this helps!!!

16-11-2009, 09:26 PM	#3
shimmy CSL Register Uber-poster! Join Date: Apr 2008 Location: Uk Posts: 14,646 Casino cash: $43909	my car had leaky side seals at 60k miles had BMSport replace all 3 seals and all is still well and diff going strong (i reckon most fo the failing diffs you see on CSLs are due to loss of fluid at seals)

16-11-2009, 10:21 PM	#4
bromers S4 - Getting the hang of it Join Date: May 2009 Location: UK Posts: 189 Casino cash: $4347	Had mine done under warranty after about 13k miles (2 yrs).

17-11-2009, 03:32 PM	#8
_Nathan_ Driving it like I nicked it Join Date: Sep 2008 Posts: 2,099 Casino cash: $13060	I'd have thought it was done by Schirmer as the diff was modified I believe.

17-11-2009, 04:40 PM	#9
DuncanR CSL Register Uber-poster! Join Date: Sep 2009 Location: Olney, Bucks Posts: 3,735 Casino cash: $9984	Good call Matt on the 2 year warranty, thanks will investigate further. I saw Tom Schirmer on Friday, I need to email him on another matter so will ask him, and of course Andrew who will know better than anyone ! mmm modified diff ??? maybe thats what makes the Black ones quicker !