Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: underi on 27 September 2024, 10:00:25

Title: 2.6 v6 rear diff fill plug knackered
Post by: underi on 27 September 2024, 10:00:25
Hey. Finally got my Omega to pass MOT. Noticed that the LSD is not working, the inside wheel spins freely and the rear kind of rumbles when trying to get the car to slide. Wanted to change the diff oil with some 75w-90 LS gear oil but the fill plug is practically destroyed. Are screw extractor tools any good? Would most likely need quite a bit of bite to get it loose. I read about there being some kind of a breather hole on top of the diff that you can fill from, is there any more information on how to remove it etc.? Thanks.
Title: Re: 2.6 v6 rear diff fill plug knackered
Post by: Doctor Gollum on 27 September 2024, 11:26:44
What makes you think it has an LSD fitted?
Title: Re: 2.6 v6 rear diff fill plug knackered
Post by: GastronomicKleptomaniac on 27 September 2024, 12:31:14
If you're in the UK it's very unlikely you have an LSD.

However, to remove the filer plug... Penetrating oil (I like Bulldog BDX but Gt85 is cheaper) and heat will help.

Title: Re: 2.6 v6 rear diff fill plug knackered
Post by: underi on 27 September 2024, 23:22:44
If you're in the UK it's very unlikely you have an LSD.

However, to remove the filer plug... Penetrating oil (I like Bulldog BDX but Gt85 is cheaper) and heat will help.

I'm located in Finland and I've been told that most of the V6 Omegas here have been fitted with an LSD. If there's a code for the LSD option in the owner's manual or something I'd be happy to check that.
Title: Re: 2.6 v6 rear diff fill plug knackered
Post by: Doctor Gollum on 27 September 2024, 23:54:32
With the rear jacked up, in neutral, rotate one rear wheel. If the other side turns the same way, it's an LSD, if not it isn't.
Title: Re: 2.6 v6 rear diff fill plug knackered
Post by: Nick W on 28 September 2024, 09:49:27
Back to the original question about the fill plug: weld a short length of close fitting steel stock(or whatever you've been using up to now) into the rounded off hole and loosen the plug while it's still hot. Don't refit it :y
Title: Re: 2.6 v6 rear diff fill plug knackered
Post by: GastronomicKleptomaniac on 28 September 2024, 12:46:26
If you're in the UK it's very unlikely you have an LSD.

However, to remove the filer plug... Penetrating oil (I like Bulldog BDX but Gt85 is cheaper) and heat will help.

I'm located in Finland and I've been told that most of the V6 Omegas here have been fitted with an LSD. If there's a code for the LSD option in the owner's manual or something I'd be happy to check that.

Ah that makes sense!

With the rear jacked up, in neutral, rotate one rear wheel. If the other side turns the same way, it's an LSD, if not it isn't.

Does that work wirh Omegas? I know it depends on the type of LSD but can I balls remember whats on our car.
Title: Re: 2.6 v6 rear diff fill plug knackered
Post by: dave the builder on 28 September 2024, 16:54:28
IF it is an LSD then there is a special fluid for it ,not just gear oil  ;)
Title: Re: 2.6 v6 rear diff fill plug knackered
Post by: Enceladus on 29 September 2024, 05:20:06
If you're in the UK it's very unlikely you have an LSD.

However, to remove the filer plug... Penetrating oil (I like Bulldog BDX but Gt85 is cheaper) and heat will help.

I'm located in Finland and I've been told that most of the V6 Omegas here have been fitted with an LSD. If there's a code for the LSD option in the owner's manual or something I'd be happy to check that.
Might be most Finnish market Omegas. I'm pretty sure that another Finnish forum member has a 4 cylinder with a factory LSD.

Is the model tag still on the differential? A photo of it might help. The letter "S" in the second space of the lower line of characters on the tag indicates an LSD. O or is it 0 indicates a standard diff.
Title: Re: 2.6 v6 rear diff fill plug knackered
Post by: biggriffin on 29 September 2024, 21:27:55
Just pop a drive shaft out, if you see 4 pins it's LSD, if you see 2 pins it's open.

Also don't use normal EP75/80w it doesn't contain the correct additives, use Amsoil,  I did put a link in another thread
Title: Re: 2.6 v6 rear diff fill plug knackered
Post by: RallyArde on 30 September 2024, 12:55:31
I had to open the fill plug twice with same method, I welded (carefully) a hex key on it and just spin it off :) By this far I´ve used Red Line 75W -90 GL 5+, and it has worked perfectly = no one tire fire ;D

With the rear jacked up, in neutral, rotate one rear wheel. If the other side turns the same way, it's an LSD, if not it isn't.

There is no preload in B/B2 Omegas LSD, so that generic trick may not work. I quess best way to find out is try to wheelspin on gravel yard and see that there are two tire marks left behind.

If the diff is original, you can use your cars VIN-number in this page to see whether its LSD or open:

http://astra-3.pl/vin.php?lang=en
Title: Re: 2.6 v6 rear diff fill plug knackered
Post by: underi on 01 October 2024, 21:13:56
If the diff is original, you can use your cars VIN-number in this page to see whether its LSD or open:

http://astra-3.pl/vin.php?lang=en
Thanks for this. I checked it and it does say that this car came with factory LSD, option code G80. I ended up getting the plug out with a screw extractor set, had already put my MMA welder ready if need be. Bought some Mobil1 diff oil with the LS additive already in it.
Title: Re: 2.6 v6 rear diff fill plug knackered
Post by: GastronomicKleptomaniac on 02 October 2024, 11:45:49
If the diff is original, you can use your cars VIN-number in this page to see whether its LSD or open:

http://astra-3.pl/vin.php?lang=en
Thanks for this. I checked it and it does say that this car came with factory LSD, option code G80. I ended up getting the plug out with a screw extractor set, had already put my MMA welder ready if need be. Bought some Mobil1 diff oil with the LS additive already in it.

That's very good news!
Title: Re: 2.6 v6 rear diff fill plug knackered
Post by: underi on 05 October 2024, 00:11:55
Here's a couple of pictures I took in the process. I'm 99% sure that the diff oil inside was original. It's fun reading guide articles from this forum that were written 10-15 years ago when the car was practically brand new and rust free, everything should come off nicely and without destroying the thing that you're trying to remove. Anyways, the LSD seems to be working again, which makes me happy. Now off to fix the next problem, no heat from the climate control.

(http://lolxd.fi/f/7u6PSc)(http://lolxd.fi/f/Pb5rcC)