Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: JamesV6CDX on 16 January 2008, 13:53:28
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I have two problems, not sure if linked.
1) I am convinced that the ride height of the rear of my car is too low. I appreciate I have a gas tank etc and I carry a fair few tools which will add extra weight and lower it a BIT, but the rear of the car is sat as if there's a burger van hitched on the back!
2) Rear tyre wear doesn't seem consistent. I've had the tyres on the back of my car for about 7k miles, and having just looked at them, I rekon they're only just legal.
The OSR one is wearing evenly across the whole tyre, but seems to have worn down to the markers VERY fast.
The NSR one has worn down equally as quick, only there is uneven wear, the most wear being about 2cm in from the shoulder of the tyre.
Now I know I have a slight buckle on one of my rear wheels, which gives me a vibration over about 75mph. Not sure which wheel. Could this cause the uneven wear on that tyre?
Opinions on the issues most welcome - cheers
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I have two problems, not sure if linked.
1) I am convinced that the ride height of the rear of my car is too low. I appreciate I have a gas tank etc and I carry a fair few tools which will add extra weight and lower it a BIT, but the rear of the car is sat as if there's a burger van hitched on the back!
2) Rear tyre wear doesn't seem consistent. I've had the tyres on the back of my car for about 7k miles, and having just looked at them, I rekon they're only just legal.
The OSR one is wearing evenly across the whole tyre, but seems to have worn down to the markers VERY fast.
The NSR one has worn down equally as quick, only there is uneven wear, the most wear being about 2cm in from the shoulder of the tyre.
Now I know I have a slight buckle on one of my rear wheels, which gives me a vibration over about 75mph. Not sure which wheel. Could this cause the uneven wear on that tyre?
Opinions on the issues most welcome - cheers
Yes it probably is the one giving uneven wear.......but easiest way to tell, is jack it up and spin the wheels.......it was very obvious on my veccyC to spot the buckled wheel....that gave rear end vibration at motorway speeds.
But its also worth checking the inside tyre walls for damage/bulging.....i would imagine that would give vibration too.
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If it's a buckled wheel the wear pattern will change over the tyre's circumference. Has it worn on the other edge at 180 degrees to the wear you noticed, for example?
Ride height will affect the other parameters of the suspension if it's incorrect, but for the wheel that's wearing evenly this isn't really an explanation. Maybe the rear toe is out?
Maybe you should stop hoofing it out of roundabouts? ;)
I guess it might be worth checking for a broken spring? I guess that'd be unlikely to affect both sides though. Doesn't have the self levelling setup, presumably?
Has it had a geometry setup recently?
Kevin
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If it's a buckled wheel the wear pattern will change over the tyre's circumference. Has it worn on the other edge at 180 degrees to the wear you noticed, for example?
Ride height will affect the other parameters of the suspension if it's incorrect, but for the wheel that's wearing evenly this isn't really an explanation. Maybe the rear toe is out?
Maybe you should stop hoofing it out of roundabouts? ;)
I guess it might be worth checking for a broken spring? I guess that'd be unlikely to affect both sides though. Doesn't have the self levelling setup, presumably?
Has it had a geometry setup recently?
Kevin[/quote
And doing lots of driving in the 5/6k rpm range in low gears. ;)
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I'm pretty sure when it was still STMO's car it did actually look quite low at the back anyway...
being no expert tho i cant say too much but what tyres are you using? are you generally heavy footed when driving?
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Yes, I'm generally heavy footed. And I'm not prepared to change ;)
Heavy footed or not though, there's still an issue re. the uneven tyre wear...
It LOOKS like over-inflation, (more wear in the middle than the edges) but they're kept at the correct pressures.
How low do other Omega's sit?
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James, i had an issue with rear tyres appearing to be over inflated and kept them at the correct pressures as the book states, but i have experimented with various settings and found that if you reverse the front and rear tyre pressures, ie front settings to the rears and rears to the front then the tyre ware evens its self out. try it you have nothing to lose. Ps did it stop raining long enough to get the cams out ::) :y
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The tank weighs about the same as a person
Try estate springs
I'm fitting lowering ones to mine when financially sorted
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The tank weighs about the same as a person
I wonder if the position of the weight (tank) causes more of a pendulum affect on the rear than rear seat passengers?
I guess the best person to speak to would be Tony at WIM once you have checked the springs and shocks.
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Ps did it stop raining long enough to get the cams out ::) :y
No, it didn't stop raining at all...
... but I put my raincoat on and removed them for you anyway ;)
I'm just about to be taken out for a Meal 8-) But I'll sort out the postage tomorrow :)
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James,
I have a 70l in mine and it has made little difference to the ride height and that include having it full of LPG and petrol at the same time.
When you posted pics up in the Gallery i noticed that it was riding low on the back, even a big tool box shouldn't cause that much difference.
I would be inclined to look at the springs and shocks, what sort of condition are they in?
The OSR tyre sounds like it has worn normally, could it be a soft compound tyre, i was getting 10k out of tyres in the past in the back and 7k on the front
the NSR sounds a bit strange, is the wear on the outside or inside edge of the tyre, if it was inside i would say camber adjustment on the back
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The wear is closer to the outside Jay, however the very outside shoulder has got loads of meat on it.....
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The wear is closer to the outside Jay, however the very outside shoulder has got loads of meat on it.....
that's a wierd one, i have not seen that in the past....
any chace of getting a pic of the tyre whilst on the car?
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The wear is closer to the outside Jay, however the very outside shoulder has got loads of meat on it.....
Thats sudgests the tyre it self is de-laminating.....which could well be your vibration to.....and its not a good thing to be happening!
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The wear is closer to the outside Jay, however the very outside shoulder has got loads of meat on it.....
Thats sudgests the tyre it self is de-laminating.....which could well be your vibration to.....and its not a good thing to be happening!
The thing is Mark, I was having the vibration before renewing tyres. I renewed the tyres, in the hope of curing the vibration. The tyre is litreally only a couple of months old, and the condition looks great, apart from the uneven wear :-/
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Hi James.
I am not sure how old your car is but mine is a 96. On the last MOt it failed on the two big rear subrame bushes being worn & split. After there were chaned the back end of the car came up noticibly. My headlights not need to be adjusted upwards quite an amount to compensate. doubt that would explain the tyre wear unlss one had failed & other was hanging on.
Jez
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The wear is closer to the outside Jay, however the very outside shoulder has got loads of meat on it.....
Thats sudgests the tyre it self is de-laminating.....which could well be your vibration to.....and its not a good thing to be happening!
An interesting point.
There are a certain number of wear patterns that can be attributed to suspension geometry, tyre pressure, etc. Extreme shoulder wear, uneven wear biased to one side or the other, centre wear, wear on both edges, etc.
If it follows a different pattern, which yours appears to, it means the tyre is going out of shape or not running true. As the tyre is relatively new is it worth taking it back where you got it from for an opinion?
Don't necessarily ask for a replacement, but tell them you're concerned about it and ask if, in their opinion, it's safe, and if they say no, play the "well it must have been faulty, then" card.
Kevin
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General tyre wear, if pressures and alignment, bushes etc are correct, should obviously be even across the tread face. If load carried is greater than that recommended for specific (unladen) pressure, shoulder wear will result. If you combine enthusiastic use of roundabouts and its wearing on the outside edge of the RNS then, alignment apart, the answer is under your right foot.
The vibration will most probably be an out of round rim, confirmed by yourself when the tyres were recently replaced.
As to swapping pressures front to rear, the unladen pressures for my 3 litre saloon are the same F & R. If its the laden pressures, then I certainly would be concerned if the fronts were at 42 psi and the rears ar 36. It could easily scrub into corners, especially in the wet, and the shoulder wear will be immense. Also, in my opinion, the rear will wallow out if the car is actually at 'laden' weight...
I would take care in swapping F&R pressures....
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JAMES WHAT ARE THE SIZE TYRES THAT YOU RUN, AS 205/65/15/94 SHOULD BE
FRONT=31.5PSI
REAR =31.5PSI UNLADEN
FRONT=36PSI
REAR =42PSI FULL LOAD
225/55/16
FRONT=31.5PSI
REAR =31.5PSI UNLADEN
FRONT=36PSI
REAR =42PSI FULL LOAD