Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Brewster on 30 October 2007, 12:39:59

Title: Sourcing a diff
Post by: Brewster on 30 October 2007, 12:39:59
As I have mentioned before, the diff on my 3.0 MV6 is whining a little. Whilst it hasn't got any worse in the past 5k miles and still runs fine I think it'd be prudent to get hold of another, just in case. Can anyone tell me if the diff on this car is the same as the 2.5? If they are the same fitment but different ratios I can live with that as I don't do silly speeds in 3.0 anyway.

Thanks
Title: Re: Sourcing a diff
Post by: tunnie on 30 October 2007, 13:36:42
the diff would be the same for 2.5/3.0 i think.

You may have a limited slip diff on your mv6 but this is unlikey.
Title: Re: Sourcing a diff
Post by: Brewster on 30 October 2007, 13:43:04
I'm pretty sure it isn't an LSD on there currently. I'm not even sure it needs replacing, it's just noisey, but after my crank sensor debacle I'd rather be safe than sorry and have one ready just in case. :)
Title: Re: Sourcing a diff
Post by: GastronomicKleptomaniac on 30 October 2007, 15:46:25
If the ratios are different, it will throw your speedo out. Just a consideration. :)
Title: Re: Sourcing a diff
Post by: Marks DTM Calib on 30 October 2007, 16:03:39
Quote
If the ratios are different, it will throw your speedo out. Just a consideration. :)


It wont, the speedo signal is derived from the ABS sensors which are post diff.
Title: Re: Sourcing a diff
Post by: Paul M on 31 October 2007, 14:31:23
The 2.5 diff has a higher ratio, giving lower gearing overall. Which is a good thing IMO, unless you spend 90% of your time cruising on the motorway. The difference is pretty small anyway, the actual figures are listed at autobahnstormers.org

3.0 MV6: Manual        240 mm        3.81:1        2.11:1        1.34:1        1.00:1        0.81:1        3.40:1        3.70:1
2.5 CDX: Manual         228 mm        3.95:1        2.19:1        1.39:1        1.00:1        0.85:1        3.53:1        3.90:1

First figure is the clutch diameter, then the gear ratios from 1st to 5th, then the reverse gear ratio, and finally the diff ratio. So the 2.5 diff gives 5% lower gearing than the 3.0 diff :)
Title: Re: Sourcing a diff
Post by: GastronomicKleptomaniac on 31 October 2007, 15:04:00
Quote
Quote
If the ratios are different, it will throw your speedo out. Just a consideration. :)


It wont, the speedo signal is derived from the ABS sensors which are post diff.

 :D D'oh. Bloody new fangled things, I'm used to bloody old F**ds... *another bit to note* :y
Title: Re: Sourcing a diff
Post by: Brewster on 31 October 2007, 16:16:14
Well, as long as they both fit it gives me more options. Now it's just a case of finding one. Many thanks.
Title: Re: Sourcing a diff
Post by: tunnie on 31 October 2007, 17:22:09
Quote
Well, as long as they both fit it gives me more options. Now it's just a case of finding one. Many thanks.

Quite a few members are breaking cars currently... so its worth posting up  :y
Title: Re: Sourcing a diff
Post by: Brewster on 02 November 2007, 19:45:22
Can anyone tell me whether there is a difference between the diffs used on manual and automatic V6s? I'm hoping they are the same as they are in the final drive....
Title: Re: Sourcing a diff
Post by: Brewster on 06 November 2007, 12:42:34
Anybody?
Title: Re: Sourcing a diff
Post by: Elite Pete on 06 November 2007, 13:04:35
Is there oil on the diff casing? It could be your diff needs a top up or better still replace the oil.
Title: Re: Sourcing a diff
Post by: Brewster on 06 November 2007, 13:09:05
Yeah, there's plenty of oil in the diff. It is a bit black, but a change won't cure the whine I don't think. I'm just wondering if the diff on an automatic is the same as on a manual. :)
Title: Re: Sourcing a diff
Post by: Kevin Wood on 06 November 2007, 14:02:25
I would be very surprised if they're physically different but they may well be different ratios between auto and manual.

Kevin
Title: Re: Sourcing a diff
Post by: ians on 06 November 2007, 14:14:52
I think they are different - also pre/post mini facelift.  The ratios are listed in Haynes.
Title: Re: Sourcing a diff
Post by: Marks DTM Calib on 06 November 2007, 14:26:11
3.0 Auto and 2.5 Auto/Manual are the same ratio, 3.0 Manual is different....
Title: Re: Sourcing a diff
Post by: Mole on 06 November 2007, 14:30:08
I fitted an lsd to my explod mv6 and also to the 2.0 batomegabile and while they are different they will fit.
The flange at the front of the diff is bigger on the 3.0 than the 2.0 but can be swapped over.(taking care with
retightening the nut to the same position as it was taken off). Not sure about the 2.5 but the same applies.
the mounting bracket is also different but again will fit. Try to make sure you get the mount with the diff.
The drive shafts are the same fitting into the diff throughout (although different in other ways).
Hope this helps.
Title: Re: Sourcing a diff
Post by: Brewster on 06 November 2007, 14:53:27
Cheers for the help. It looks like it might be easier trying to get hold of a 3.0 manual diff as a straight swap then.
Title: Re: Sourcing a diff
Post by: Marks DTM Calib on 06 November 2007, 15:04:13
Quote
Cheers for the help. It looks like it might be easier trying to get hold of a 3.0 manual diff as a straight swap then.

Its the only easy way due to the difference in ratios of the 2.5 (V6's use the same flange)