Omega Owners Forum
Chat Area => General Car Chat => Topic started by: 3.2 manual on 06 April 2019, 13:40:09
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Modification to improve handling.
Tried to post a picture but can't work out how lol.
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Broken wishbones coming to a car near you :-X
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I am wondering about that, with the front ones polybushed too. Shock loading will be greater but the wishbone is absolutely free to move up and down with little to no resistance. lol
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Broken wishbones coming to a car near you :-X
A solid poly bush in this position transfers the movement to the structure of the wishbone, which is what causes it to break -just like bending a paper clip to and fro.
A spherical bearing constrains the movement to the ball and socket within the bearing, a structure that is specifcally designed to do that. There's no cushioning effect from this sort of joint though, so the extra control is at the cost of a lot more harshness, noise and durability. As the other two attachment points are still bushed, I don't think the disadvantages are worthwhile on a road car, let alone one that is supposed to be a big comfortable car.
The poly front wishbone bushes function by rotating about the axis of the bolt, just like the original did. The difference is that the bushing material isn't bonded to the sleeve, so isn't damaged by poor fitting or wear.
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The poly bushes don't wear, whereas these spherical bushes will end up wearing quickly with dirt ingress. Net result they will break up and either fall apart of seize... Either way the wishbone won't be far behind...
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The poly bushes don't wear, whereas these spherical bushes will end up wearing quickly with dirt ingress. Net result they will break up and either fall apart of seize... Either way the wishbone won't be far behind...
That is the net result, but you'll be surprised how long they last even when completely exposed like on a four link. You get lots of warning too.
It is one of the disadvantages that I'm not prepared to accept on any sort of road car.
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I did consider all of this, being a fitter by trade. The noise etc hasn't changed much due to the massive profile of the tyres. The sphericals are sealed maintainance free ptfe units, where in a different application under a lorry they were successfully dealing with over 3000kg of loading a piece. It has been done as an experiment and a close eye will be kept on the wishbones. I will post the results after a while of use. It is now very precise in corners so bonus for now :D
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We had some early success with a couple of different poly bushings, but wishbones failed on both cars after about 8k miles.
I had checked mine the week before the arm snapped and there was no evidence of the impending failure. One minor crest on a fast A road was enough to shear the arm without warning. A different make of wishbone might have lasted longer, or not, but that was the end of the experiment as a second failure at speed might not have been so lucky.
Also, with rigid rear bushes, the front tie should be set to zero as the factory toe setting allows for give within the rear bush. You'll get a slight dead spot straight ahead but this is a normal side effect of a steering box. :y
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Cool thanks for the figure of failure time frame. Geometry set to 0.The reason I went for sphericals in the rear of the front arm instead of polybushes is I considered the force of flexing polybushes in that axis would be unsustainable for the wishbones as I have seen them snap in other cars before.
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We had some early success with a couple of different poly bushings, but wishbones failed on both cars after about 8k miles.
My wishbone didn't fail. The poly did :D, Cant remember the mileage, wasn't many though.
I guess it finds the weakest point.
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Your probably right, it's currently searching for it on mine now lol ;D
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They do drive well though 8)
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They do drive well though 8)
Yup, mine was brilliant until the poly started to fail, then went drastically downhill fast. Really tightened up the (usually lacklustre) steering response.
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We had some early success with a couple of different poly bushings, but wishbones failed on both cars after about 8k miles.
I had checked mine the week before the arm snapped and there was no evidence of the impending failure. One minor crest on a fast A road was enough to shear the arm without warning. A different make of wishbone might have lasted longer, or not, but that was the end of the experiment as a second failure at speed might not have been so lucky.
Also, with rigid rear bushes, the front tie should be set to zero as the factory toe setting allows for give within the rear bush. You'll get a slight dead spot straight ahead but this is a normal side effect of a steering box. :y
Those failed as the restricted rhe rotational movement to much and placed extra load on the weld joint, spherical joint would address that :y
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We had some early success with a couple of different poly bushings, but wishbones failed on both cars after about 8k miles.
I had checked mine the week before the arm snapped and there was no evidence of the impending failure. One minor crest on a fast A road was enough to shear the arm without warning. A different make of wishbone might have lasted longer, or not, but that was the end of the experiment as a second failure at speed might not have been so lucky.
Also, with rigid rear bushes, the front tie should be set to zero as the factory toe setting allows for give within the rear bush. You'll get a slight dead spot straight ahead but this is a normal side effect of a steering box. :y
Those failed as the restricted rhe rotational movement to much and placed extra load on the weld joint, spherical joint would address that :y
If you cut an original rear bush in half you will find a bulge in the steel sleeve (that looks remarkably like a sphere) with a rubber bush cast around it.
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Removing the rubber from the equation also removes any impact shock resistant. It may well fail differently.
The only real test is time and mileage driving it properly :y
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Removing the rubber from the equation also removes any impact shock resistant. It may well fail differently.
The only real test is time and mileage driving it properly :y
that's likely to accelerate the wear in the spherical joint; the wishbone is still functioning as it was designed to.
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Wishbones still good, driven hard on Welsh mountain roads. No noise above normal, handles like its in rails and wearing front tyres flat and square! I'm calling it a success lol :D
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Wishbones still good, driven hard on Welsh mountain roads. No noise above normal, handles like its in rails and wearing front tyres flat and square! I'm calling it a success lol :D
Still good after seven weeks, eh?
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Wishbones still good, driven hard on Welsh mountain roads. No noise above normal, handles like its in rails and wearing front tyres flat and square! I'm calling it a success lol :D
Mine were still good the week before they snapped :-X
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Wishbones still good, driven hard on Welsh mountain roads. No noise above normal, handles like its in rails and wearing front tyres flat and square! I'm calling it a success lol :D
Mine were still good the week before they snapped :-X
He's using bearings instead of bushes,should lessen the load on the bones not increase it :y
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Wishbones still good, driven hard on Welsh mountain roads. No noise above normal, handles like its in rails and wearing front tyres flat and square! I'm calling it a success lol :D
Mine were still good the week before they snapped :-X
He's using bearings instead of bushes,should lessen the load on the bones not increase it :y
And when the bearings fail, where does the load go?
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Wishbones still good, driven hard on Welsh mountain roads. No noise above normal, handles like its in rails and wearing front tyres flat and square! I'm calling it a success lol :D
Mine were still good the week before they snapped :-X
He's using bearings instead of bushes,should lessen the load on the bones not increase it :y
And when the bearings fail, where does the load go?
the same place as when the bush does. Once again, the bearing is a straight replacement for the bush and doesn't change how the wishbone was designed to work. The experiments with different types of bush did that, which is the cause of the failures. All wishbones that use the design of two bushes working at 90° to each other wear as badly as Omega ones. Escorts and Fiestas are common examples. So are the separate arms BMW used. My opinion is they're a poor design that are cheap to build.
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I'm glad somebody else actually understands the modification.
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She's been up over 130mp...erm..coffees, yes coffee's that's what I meant to say. For 35mil... Coffees cornering hard. Like she's in rails. Part numbers available.
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Only when the bearings fail I get 0.5mm of play, not the 10mm of play with bushes :D
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With the tyres removed and some rails laid, i'm sure further improvements could be made to the steering :-\
got any links to the bushes spherical bearings ?
so I can see what they are please
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With the tyres removed and some rails laid, i'm sure further improvements could be made to the steering :-\
got any links to the bushes spherical bearings ?
so I can see what they are please
I'll send you a pic of my spherical objects, Dave ;D
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They hang a bit low these days, so I'll airbrush my knees out. ;D
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With the tyres removed and some rails laid, i'm sure further improvements could be made to the steering :-\
got any links to the bushes spherical bearings ?
so I can see what they are please
I'll send you a pic of my spherical objects, Dave ;D
No thanks Uncle Stemo
It's roast chicken tonight ,was hoping to keep it in my stomach :y
thanks all the same :)
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Yes but I don't seem to be able to post pictures off my phone, for some reason.