Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: mark3 on 31 March 2012, 14:37:27
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My Omega has, some time ago, developed a pull to the left, even when driving on an adverse camber it would still drift to the left, had geometry checked and found Castor angles was out (o/s more than the n/s) due to the weight in the rear lowering the rear of the car, this was also causing the rear camber to go more negative than it should be, so inner edges of tyres wearing.
Now i had two choices, to fit heavy duty springs to raise the rear of the car back up to where it should be, putting the front Castor back into limits and add + camber to rear wheels OR leave it as is, which i do prefer visually, and make changes else where.
I chose the later as i like the car looking level, so i had the rear tracking adjusted slightly more toe in than specified to spread the wear across the tyres, which has worked a treat, and i created some adjustment to the front Castor which is now exactly as specified.
Front camber has been altered to its maximum negative to make turn in feel more positive and along with a new o/s/f wheel bearing, o/s/f lower ball joint/wishbone, replacement front shocks and top mounts fitted and another trip to have the alignment checked i now have everything exactly where it should be BUT i still have a very very slight drift to the left, its much much improved so now on adverse camber it will now drive to the right but its not perfect.
Now as its really not that bad at all now i can quite happily live with it but i was hoping after this amount of work and set up and cost involved i would have had it absolutely spot on so im wondering what i might have missed?
New rear shocks being fitted next week but i cant see the rears causing this
And yes, try pressures are all as should be, brakes aren't binding and there is no suspension/steering play/tightness anywhere.
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Uneven wear on the tyres can cause it to pull
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Uneven wear on the tyres can cause it to pull
Well obviously that goes without saying....... front tyres are new, rears are good.
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If the tyres are non directional/asymmetric might be worth swapping them to tother side. Or even if they are directional, if it's dry swap them to eliminate that possibility perhaps? Bit of a faf to swap em back though. :-\
What's the rear camber/toe settings? and is the rear drive line central.(forget the technical term)
....in fact can you post a pic of the set up sheet? Particularly the after settings.
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If the tyres are non directional/asymmetric might be worth swapping them to tother side. Or even if they are directional, if it's dry swap them to eliminate that possibility perhaps? Bit of a faf to swap em back though. :-\
What's the rear camber/toe settings? and is the rear drive line central.(forget the technical term)
....in fact can you post a pic of the set up sheet? Particularly the after settings.
Rear thrust angle. That's the one. ...long day. :)
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mine always pulls to the left abit its the camber in the road, went on a runway nice and flat no pulling at all.
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....in fact can you post a pic of the set up sheet? Particularly the after settings.
Before
(http://i943.photobucket.com/albums/ad272/mobilemechanic_org/Omega/Omegageometry001.jpg)
And after
(http://i943.photobucket.com/albums/ad272/mobilemechanic_org/Omega/Omegageometry002.jpg)
Since then i have had the rear toe adjusted slightly more than specified to spread the wear of incorect camber.
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At the rear I'd concider raising ride hight to get the settings correct, rather than compromise to get round it. There are spring assisters and or firmer/longer spring options as I'm sure you know.
Re the pull, nothing obvious springs to mind looking at the settings afaict. Although on re reading your first post, looks like only one wishbone was changed?
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Racking my mind if the castor has been set the right way...
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was the test done with your tools etc in the back?
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Test was done with all tools in the car that are normally there and half tank of fuel too.
Only one wishbone was changed this time BUT 2 years ago i fitted a matched pair thinking the one i changed the year before may have had an effect on the castor angle/pull to the left, fitting a matched pair didnt alter things until i created some Castor adjustment. fitting this one new wishbone also made no difference.
And i was toying with the idea of raising the rear but i like it as is, i spent time and money getting the front geometry right to keep the rear at the hight it is now so i wont be looking at raising it, the drift to the left is now so so much better than it ever was i can happily live with it.
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Racking my mind if the castor has been set the right way...
It prolly hasnt as Omega's dont actually have any castor adjustment :y but mine has ;)
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Racking my mind if the castor has been set the right way...
It prolly hasnt as Omega's dont actually have any castor adjustment :y but mine has ;)
Not strictly true .. castor can be adjusted by moving the sub-frame ... Seen it done at WIM a couple of times .. :)
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Racking my mind if the castor has been set the right way...
It prolly hasnt as Omega's dont actually have any castor adjustment :y but mine has ;)
Not strictly true .. castor can be adjusted by moving the sub-frame ... Seen it done at WIM a couple of times .. :)
Ah ha! yes i spose it would.... well i didnt do that, i created movement at the front bushes of the wishbones.... prolly about 8mm in total each side.
And what i meant is there isnt any purpose made castor adjustment, :y
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Racking my mind if the castor has been set the right way...
It prolly hasnt as Omega's dont actually have any castor adjustment :y but mine has ;)
Not strictly true .. castor can be adjusted by moving the sub-frame ... Seen it done at WIM a couple of times .. :)
Ah ha! yes i spose it would.... well i didnt do that, i created movement at the front bushes of the wishbones.... prolly about 8mm in total each side.
And what i meant is there isnt any purpose made castor adjustment, :y
The adjustment available is fairly large as the subframe holes are considerably larger than the bolt diameter. Weather that is designed in, who knows. But certainly very little attention was paid to the correct position on the production line.
Master mentioned earlier cars had more "adjustment" in the subframe position, which caused problems to be rectified on newer cars. Not sure of the cut off point.
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Am wondering ............. (as only one wishbone was latterly changed):
The (newer) lower ball-joint may be 'tighter' than it's (older) counterpart? :-\
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The geometry has been checked and adjusted since then.
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been looking on other web pages and only things keep poping up is over weight in boot area and cliping curbs, and rear sliding round courners. but then there are loads of other people saying that they use alot of tyers on rear, as the inner walls wear out and they had it checked and is in line so i dont know.
ask Kevin wood he was one replying to some one on one form.
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Am wondering ............. (as only one wishbone was latterly changed):
The (newer) lower ball-joint may be 'tighter' than it's (older) counterpart? :-\
Main concern is usually uneven front bush performance on the brakes. Although if the bushes have failed enough, ccontrol of the wheel position could be fine on the ramp during set up and then toe out while driving.... "Could"
Although the op dousnt mention any oddness while braking. ...?
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Am wondering ............. (as only one wishbone was latterly changed):
The (newer) lower ball-joint may be 'tighter' than it's (older) counterpart? :-\
Main concern is usually uneven front bush performance on the brakes. Although if the bushes have failed enough, ccontrol of the wheel position could be fine on the ramp during set up and then toe out while driving.... "Could"
Although the op dousnt mention any oddness while braking. ...?
It brakes fine, infact it drives lovely all round apart from a slight driftt to the left, lol
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Dunno then. Can't tell from here anyway. Maybe swap the wheels around, see if that makes any odds. -1.40 is a bit aggressive to be fair and may incur some edge wear that affects things. Really need to be wanging the car around a lot to justify -1.40. Up to you though, obviously.
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Its sorted at last, no more drift to the left!
As i had two brand new tyres of the same make and tread pattern fitted at to the front at the same time i assumed it wasnt them BUT it bloody was. today i noticed as soon as you move forward even by one MPH the steering wheel would turn to the left so it has to be rolling resistance, so after swapping front and rear tyres it now drives absolutely bloody perfectly.
;D :D ;D :D :) :y