Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: v6venom on 29 October 2008, 18:52:32

Title: omega diff question
Post by: v6venom on 29 October 2008, 18:52:32
just wondering if anyone can clarify something for me ...

i have 2 n plate omega`s 1 2.5 cd and 1 3ltr elite

im told that the elite has a limited slip rear diff is this the case or do i need to check and see??

any advice would be great

cheers al
Title: Re: omega diff question
Post by: Kevin Wood on 29 October 2008, 19:00:20
It won't have had an LSD as standard and very few had them as optional extras. Mainly just ex-police vehicles.

Could always try pulling over with one wheel on a grass verge and then hoofing it. :-X

Kevin
Title: Re: omega diff question
Post by: JonArgraig on 29 October 2008, 19:01:16
Quote
just wondering if anyone can clarify something for me ...

i have 2 n plate omega`s 1 2.5 cd and 1 3ltr elite

im told that the elite has a limited slip rear diff is this the case or do i need to check and see??

any advice would be great

cheers al

Almost all slipper diffs are on explod Mv6's - no civic spec in the uk came as standed.
Title: Re: omega diff question
Post by: v6venom on 29 October 2008, 19:01:35
what would i expect to happen mate as funnily enough i did that last night ... ::)
Title: Re: omega diff question
Post by: Kevin Wood on 29 October 2008, 19:03:14
If the wheel on the verge just spins and you get very little traction you don't have an LSD. If the car still pulls away reasonably smartly you do - because torque is being transferred to the other wheel that has traction.

Kevin
Title: Re: omega diff question
Post by: v6venom on 29 October 2008, 19:08:41
ahh ok well it deffo pulled away but both wheels let go as i got going and had a bit of a sideways moment ....

im guessing thats more down to the elite being more powerfull rather than lsd fitted ??

so are both rear diffs axles the same  setup ???

plan is to fit the 3ltr in the other car 2.5 cd and want to make sure as much as possible is swapped over ..

cheers al
Title: Re: omega diff question
Post by: HerefordElite on 29 October 2008, 19:43:09
Quote
ahh ok well it deffo pulled away but both wheels let go as i got going and had a bit of a sideways moment ....

im guessing thats more down to the elite being more powerfull rather than lsd fitted ??

so are both rear diffs axles the same  setup ???

plan is to fit the 3ltr in the other car 2.5 cd and want to make sure as much as possible is swapped over ..

cheers al


simpler swap would be to rob the cams from the 3 litre as that will give the 2.5 an instant 18bhp increase for a lot less hassle than a full engine swap :y
http://www.omegaowners.com/forum/YaBB.pl?num=1152565319
Title: Re: omega diff question
Post by: v6venom on 29 October 2008, 19:58:35
Quote
Quote
ahh ok well it deffo pulled away but both wheels let go as i got going and had a bit of a sideways moment ....

im guessing thats more down to the elite being more powerfull rather than lsd fitted ??

so are both rear diffs axles the same  setup ???

plan is to fit the 3ltr in the other car 2.5 cd and want to make sure as much as possible is swapped over ..

cheers al


simpler swap would be to rob the cams from the 3 litre as that will give the 2.5 an instant 18bhp increase for a lot less hassle than a full engine swap :y
http://www.omegaowners.com/forum/YaBB.pl?num=1152565319


already have a special set of kents fitted in the 2.5 mate, plan is to fit the 3 ltr n then fit the kents to that ....a mate is having the g`s & a`s for his v6 astra project ....
:y
Title: Re: omega diff question
Post by: HerefordElite on 29 October 2008, 21:09:00
Quote
Quote
Quote
ahh ok well it deffo pulled away but both wheels let go as i got going and had a bit of a sideways moment ....

im guessing thats more down to the elite being more powerfull rather than lsd fitted ??

so are both rear diffs axles the same  setup ???

plan is to fit the 3ltr in the other car 2.5 cd and want to make sure as much as possible is swapped over ..

cheers al


simpler swap would be to rob the cams from the 3 litre as that will give the 2.5 an instant 18bhp increase for a lot less hassle than a full engine swap :y
http://www.omegaowners.com/forum/YaBB.pl?num=1152565319


already have a special set of kents fitted in the 2.5 mate, plan is to fit the 3 ltr n then fit the kents to that ....a mate is having the g`s & a`s for his v6 astra project ....
:y


RWD or wrong wheel drive? ::)
Title: Re: omega diff question
Post by: v6venom on 29 October 2008, 21:29:57
front wheel mate just another toy for show season ... 8-)
Title: Re: omega diff question
Post by: pete.h on 30 October 2008, 00:50:34
The easiest way to tell if it's an lsd is to jack both back wheels off the ground .
Put it in gear if it's manual or park if it's auto(to stop the propshaft turning)
 Turn one wheel by hand . If the other wheel goes in the opposite direction it's a standard diff.  If it goes in the same direction it's an lsd.

Also if you do fit an lsd remember to tell your MOT station.  If they do a standard roller brake test it can wreck your diff or tyres or both.
They have to do a road brake test using a deccelerometer instead.
Title: Re: omega diff question
Post by: GmasterT on 30 October 2008, 14:59:42
dont need it in gear or it will never turn!

Jack it up in neutral and spin a wheel, if the other spins the same direction is lsd, if opposite direction standard open, in nothing, knackered!  :D
Title: Re: omega diff question
Post by: pete.h on 30 October 2008, 15:12:29
If you don't put it in gear the propshaft tends to turn instead of the opposite wheel , because there is less resistance to turning on the propshaft , especially on a disc braked car where the pads grip the discs slightly and prevent the wheel from spinning totally free.
Title: Re: omega diff question
Post by: Kevin Wood on 30 October 2008, 15:32:40
Quote
If you don't put it in gear the propshaft tends to turn instead of the opposite wheel , because there is less resistance to turning on the propshaft , especially on a disc braked car where the pads grip the discs slightly and prevent the wheel from spinning totally free.

The propshaft needs to turn on an LSD to allow both wheels to turn in the same direction, so in gear, if you turn one wheel the other can only turn the opposite way. The only question then is whether you can apply enough torque to overcome the LSD action.

TBH, I'd be interested if this method is reliable on Omega LSDs. It works nicely on Ford viscous coupled diffs where there is some coupling between the two output shafts even at very low torque but the Omega's LSD is a plate type which responds to input torque so may well behave as an open diff for the purposes of this test until it gets serious torque through it.

Kevin
Title: Re: omega diff question
Post by: pete.h on 30 October 2008, 15:46:11
Sorry , yeah thinking about it you're right  . The propshaft ony tends to spin on a car without lsd.  We stick them in gear if we're not sure whether to do a roller brake test on the MOT, and if it turns opposite way we.re safe , if it won't turn it's lsd.
 Hate to foot the bill for knackering someones lsd , shouldn't think they're cheap. !!
Title: Re: omega diff question
Post by: Kevin Wood on 30 October 2008, 15:53:10
Quote
Sorry , yeah thinking about it you're right  . The propshaft ony tends to spin on a car without lsd.  We stick them in gear if we're not sure whether to do a roller brake test on the MOT, and if it turns opposite way we.re safe , if it won't turn it's lsd.
 Hate to foot the bill for knackering someones lsd , shouldn't think they're cheap. !!

Yep. that's it.  :y

I doubt most drivers would know if you had knackered them, tbh. Saves them climbing out of the brake tester though.

I have a Ford viscous diff on my Westfield and it doesn't grumble on a brake tester because it doesn't run fast enough but some of the geared LSDs like the Quaiffe ATB, Torsen, etc. can bind up.

Kevin


Title: Re: omega diff question
Post by: pete.h on 30 October 2008, 16:29:53
Can't say I've ever tried one in the brake tester just in case.!

I think the problem would occur if you did the rear foot brake test to VOSA guidlines.

You're supposed to do each rear wheel individually , so you're trying to turn one rear wheel whilst the brakes on the other three wheels are effectively holding the car still so it wouldn't be able to jump out of the rollers .

With an lsd soething has to give which is either going to be the grip of the tyres on the rollers or the diff. Either way it doesn't do your car much good.

I think what most garages do is test both rear brakes together but you can get in trouble with VOSA for doing it like that .

We just do a road brake test with a Tapley meter to be on the safe side.