Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: Latchie_3.0v6 on 29 February 2012, 13:13:13
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Going to look at a LSD out of a 98 mv6 on Saturday.
Will this fit my car 99 elite
How can I tell if it is a LSD not just welded.
What would be best diff oil to use
Think that's bout it, but if anyone has any other thing I should look for just let me know
Cheers
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best oil question :
factory spec, ep80 grade oil but too thick especially in winter .. so 75W90 is recommended..
got the question wrong its for gearbox, for differential EP 90 or ep140 depending on climate..
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If it's an LSD you will see two planetary gear shafts at 90 degrees, if you look into the hole where the driveshafts locate. Open diffs have just a single shaft.
If it's welded, you won't be able to turn the driveshafts individually. If it's an open diff, this will be possible. If it's an LSD, it might be stiff to turn one wheel independently of the other, but should be possible.
BOA90LS is a common recommendation for the oil.
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best oil question : factory spec, ep80 grade oil but too thick especially in winter .. so 75W90 is recommended..
My understanding is that EP oils are not necessarily compatible with plate LSDs. You need an oil with an "LS" suffix which will have the correct friction modifiers and won't contaminate the clutch plates.
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best oil question : factory spec, ep80 grade oil but too thick especially in winter .. so 75W90 is recommended..
My understanding is that EP oils are not necessarily compatible with plate LSDs. You need an oil with an "LS" suffix which will have the correct friction modifiers and won't contaminate the clutch plates.
dont know about contamination but a quick search brings too many ep 90 or ep140 type oils for lsd
http://ebookbrowse.com/ep-90-gl5-limited-slip-msds-2-pdf-d107846895
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Omega LSD requires an EP90 with friction modifiers.
Original fit would have been EP90 with seperate additives (and this is what a dealer will supply) but LSD oils are available which have the friction modifiers already in and hence the recommendation of BOA90LS
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Also worth checking what Diff Ratio your going to end up with, if its ex plod could be different, not to mention swapping between Manual / Auto etc.
;)
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I have checked the ep type lsd oils..
seems like they use a special type of EP modifiers and their sulphur content is non-active as fas as I understand..
"EP mineral gear oils are used more extensively in worm gears. Under conditions of high pressure and temperature, the EP (antiscuff) additive reacts with the metal surface to form a soft, slippery chemical layer which prevents severe wear and welding. Previously, there was a concern that sulfur-phosphorous EP additives would react with the bronze gear. However, new EP additive technology used by most of the major lubricant suppliers has reduced the corrosive attack by utilizing nonactive sulfur. EP lubricants work particularly well when shock loading occurs. EP gear oils also protect steel gears better than compounded gear oils. "
http://www.machinerylubrication.com/Read/169/worm-gear-lubrication
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it is the "hypoid" additive in most axle oils which poisons LSD plates.
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Thanks for all the quick answers. Just another Q how much oil does diff take or is there a marker on side or anything.
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I got just over 1 ltr in my standard dif plus a tube of additive
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Just fitted the LSD that I bought and it doesn't seem to lock, would there be any reason for this, I was thinking maybe low on oil
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When you say it doesn't seem to lock, what have you tried doing?
Best test is on gravel, plenty of revs then pop the clutch, should get a nice long 11, i.e. both rears spinning and leaving tracks.
Seeing where you live it might be easier to find some wet grass! LOL
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I tried doing a few donuts in a private place :P. Wheels only spun one wheel but I was told that unless diff in tightened it can take quite a bit to get diff to lock.
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I would do a straight line test rather than donuts, see if that gets the desired results.
As for 'tightening up' I'm afraid I have no knowledge of this, sorry.
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Does anyone know if omega diff is a VicsousLSD
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I have a similar problem, should be an LSD but jack one wheel off the ground and I would think I could turn it with a load of resistance, I have none???
Not trying to hijack your thread, just getting in here so I can pick up the tips. :)
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I have a similar problem, should be an LSD but jack one wheel off the ground and I would think I could turn it with a load of resistance, I have none???
Not trying to hijack your thread, just getting in here so I can pick up the tips. :)
No problem mate.
My mate has ex plod with tightened diff and she will go round on the spot. So I'm thinking of getting it tightened soon. I know for my skyline the shims to tighten were £3 each so hope the same for miggy.
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Does anyone know if omega diff is a VicsousLSD
Nope it's a plate diff.
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you have any luck yet with the boy that shims them
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you have any luck yet with the boy that shims them
Hasn't got back to me mucker :y
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Does anyone know if omega diff is a VicsousLSD
Nope it's a plate diff.
Can the diff be refubished by any chance
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Does anyone know if omega diff is a VicsousLSD
Nope it's a plate diff.
Can the diff be refubished by any chance
I don't see why not - I imagine the bits are all available.. I'm no expert, though - 2woody (here) has probably forgotten more about diffs than I know. Maybe he'll show up here now I've mentioned his name.. :)
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it should lock up after a certain degree of slip, IIRC is it 45% or something?
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Thats what I was expecting but I think maybe inside diff is worn down possibly. There is a little bit of resistance when turning wheel by hand. But when I try to throw her round she only spins one wheel so thinking maybe diff is loose or something, I don't know anything about diff's but I do know that my mates locks nearly straight away.
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have you replaced oil? how many miles has it done with plod and since? i dont know how long the friction plates last but if very high milage and a donut fanatic previously then might need new friction plates
alex
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There was 130,000 miles on the car it came off.
Can you buy friction plates separate and are they specialist job to fit.
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Vx i think or gearbox rebuilders wil beable to do it i think
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Ok thanks I'll leave it at that. I'll have a nosy about and see what I can get done. Thanks everyone for all the feedback.
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Ok thanks I'll leave it at that. I'll have a nosy about and see what I can get done. Thanks everyone for all the feedback.
if you can find anybody who can refub an lsd let me know as i think mine is also buggered or contaminated plates in mine??
when cold it leaves lovely 11s up the tarmac but when hot it only spins 1 & intermitant on other how can i explane??
ok 1 wheel does _______ other ,,,,,,,,,, but its always the o/s that does the ,,,,,,,, n/s does ______ ???
& other thing it does on rounderbouts it snatches on cornering locking a wheel bringing on traction control but with TC off its a complete bitch when its hot!
i wonder if they do a Diff flush?? or once contaminated there fked...???
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I've had a look at the workshop manual and it shows a great exploded view showing all the assembly including the plates, I will try to get a look down one side to see the "X" then go from there, maybe a rebuild is coming my way????
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apologies for the absence....
yes, Omega B limited-slip differentials can be refurbished, but at the current cost of parts, you'll be able to buy a replacement diff and the car to which it's attached for less money. Sorry, but rebuilding one is going to appeal to only the most hardcore of enthusiasts. The plate set is about £175, whilst the bearings are around £90 each and there's four of them.
The plate-type limited-slip diff works through a ramp and the plates. There's a ramp, up which the pivot shafts for the planet wheels move - and when they move, they impart an axial force to the clutches, hence the slip-reducing action. So, the locking factor depends on the angle of the slope and the "rate" of the clutches ( for that, read pre-load ). In the Omega B diff, the plate pre-tension can be changed by machining, but the slope angle cannot. You may get a small tightening through the plate tension.
I can build a diff to order, but please remember that there's my time on top of the parts prices.
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Great explanation 2woody! Well... When I say great that is with exception to the costs you list!!! Holy cow!!! That is not cheep!
Ok, bottom line from you.... How do I check my LSD is working or indeed still fitted without taking shafts off?
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2woody, are there alternative suppliers of parts? Who supplied the diff's to VX??
GKN makes all kinds of diff's and one looks exactly like the Omega unit, I might drop them a line...
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Correction to your post - GKN made all kinds of diffs, the last being the Jaguar XJ40 unit, shortly before the diff-making facility was sold to Dana. Opel made their own I'm afraid. It could be ZF-related, but its certainly not a GKN product.
There is another possibility - but probably no cheaper. The Australian BTR diff ( now also owned by Dana ) is fitted into a casing that'll bolt directly into an Omega A rear subframe ( i.e. Carlton ). So if you can find a Carlton or Senator subframe and the corresponding BTR diff ( Lotus Carlton, Holden Commodore or Monaro, or TVR since 1994 ) and some Monza driveshafts ( as the diff has output flanges ), you can build yourself a very robust alternative. That's what I have in the Omega A race car.
The only reliable way to tell is by removing a driveshaft I'm afraid. Even so, it's not difficult.
Ignore what people will tell you about a wheel spinning backwards or vice-versa with the rear end suspended --- that's all bunkum.
you could do a mini-roundabout test - that's driving around the smallest mini roundabout you can find. The object is to spin up the inside rear wheel ( no LSD ) or get it sideways ( LSD ).
also, you'll find that if you set off from rest at full lock, slowly on a dry road, you'll hear the diff locking and unlocking, or rather you'll hear the tyres grabbing at the road surface - that's a good test if its still working
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Thanks for the info (and the correction) ;) you've given me/us plenty to think about.
Right, I'm off to eBay (.au).....
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just don't get Holden driveshafts - the subframe on a Holden, although looking identical to the Carlton one is actually a couple of inches wider.
When I had the subframe off one of the Holdens, I did a bit of experimentation.
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sorry to hijak post but how can you easy find out the diff ratios? as the seller is not prepaired to strip it down!!
ive found a 3.0 auto diff as a cheep replacement till i can get my lsd fixed but they dont know the ratio...??
i need a 3.45 out of im told a 2.2dti as atmo im running a 3.90 but its crap on the motorway on a manual box!!
is it just the 2.2dti that uses a 3.45??? & what poss ratio is the 3.0 auto diff??
cheers :y
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car seems to go round no bother now. ive noticed that when i give her a good going, the abs light comes on and then i cant turn t/c back on again.
ive also noticed that the car will go round better when this happens. when i turn car off and on again everything is back to normal.
just wondering is there any way i could have the abs disabled all the time just so the car will go round better all the time.
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casing that'll bolt directly into an Omega A rear subframe ( i.e. Carlton ). So if you can find a Carlton or Senator subframe and the corresponding BTR diff ( Lotus Carlton, Holden Commodore or Monaro, or TVR since 1994 ) and some Monza driveshafts ( as the diff has output flanges ), you can build yourself a very robust alternative. That's what I have in the Omega A race car.
i supose this has been tried but i take it that the monza diff wont take omega driveshafts if the output flanges are removed??