Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Derek_in_Penzance on 22 May 2016, 17:57:47

Title: Opel Monza limited slip diff internals into Omega B?
Post by: Derek_in_Penzance on 22 May 2016, 17:57:47
I hope nobody minds me asking this but I receive occasional enquiries from Omega B owners: will an Opel Monza limited slip diff fit into an Omega B ? (I dismantle Monzas and on most UK cars, including the Monza GSE an LSD came as standard).
Threy came in two ratios on the 2.8 and 3.0 cars; 3.15:1 and 3.45:1

I assume there might be two options: the Monza LSD unit itself onto Omega B crownwheel or Monza combo straight in. I know that the outer casings are very different although the output drive shafts are essentially the same and I imagine that the input shaft and pinion is probably very similar.

If anybody knows the answer it would be appreciated! I could try it myself but it would be very time consuming, especially getting a diff off a scrap Omega only to find that the Monza internals don't fit. If someone has already tried this I'd love to hear about it.Thanks!
Title: Re: Opel Monza limited slip diff internals into Omega B?
Post by: zirk on 22 May 2016, 18:23:09
No idea whether it will fit or not but those ratios that youve listed wont work very well on the Petrol Omega Auto / Manual gearbox ratios, which are matched with diff ratios 3.7 upwards.

The Omega 2.5TD was fitted with a 3.45 for economy but got away with it due the low end torque of the Diesel engine. 
Title: Re: Opel Monza limited slip diff internals into Omega B?
Post by: Derek_in_Penzance on 22 May 2016, 19:05:00
Thanks zirk, that's useful info. :)
Title: Re: Opel Monza limited slip diff internals into Omega B?
Post by: Bojan on 23 May 2016, 07:04:20
I have been investigating this route myself, and from what I've learned (but havent tried) the internals are the same, casings are different.
However, the ratios are too high for omega (petrol omega B came with 3.7, 3.9 and 4.22 ratio), so you should have casing and CW&P from omega B with suitable ratio. That's theory. In real world, when you take the diff apart, and reasemble it with parts from other diff, you will need various shims to get the right clearence (too much -> big backlash; too little -> very noisy  :-\ ). It isn't exactly a brain surgery, but one should have some experience and 'feel' what is the right amount of clearence, and needs a variety of shims (with different thicknes). Shims can be used ones, as they don't ususally wear out.
Title: Re: Opel Monza limited slip diff internals into Omega B?
Post by: Diamond Black Geezer on 23 May 2016, 08:50:40
Knowing that people have installed the internals from a Carlton GSi into Omega B casings, perhaps yourself, Derek would be in an almost unique position to physically compare like-for-like. I don't know how the diffs differ between Monza/Royale/Carlton/Viceroy/Senny A and the Carlton/Senator B, but it does sound 'doable'

Issue being the ratio, as said.

The other major issue being, as has been discussed elsewhere, the age and extreme wear of old LSDs, I suspect that much of the benefits of having an LSD on your car are psychological (for the road, track would be different). The suggestion is a major overhaul is required of the internals as well, which as you will know runs into three figure just for parts, before labour is included.