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[Mr Hagon]

I'm aware that the wishbone arm has a bush as part of it, but I've had both the offside and nearside front lower arm bushes split and this seems to be an MOT failure:

"Nearside front lower (rearmost suspension bush) bonded suspension unit bonding failed and part of unit is likely to become displaced [2.4.F.2].

So what's the difference between the bush in the wishbones and the one that makes you fail the MOT?

[tidla]

?? i have no idea  :-?

[PxMetro]

So what's the difference between the bush in the wishbones and the one that makes you fail the MOT?

Not really sure what you are asking here. Both bushes are bonded in the same manner, the main difference is the orientation in the wishbone arm. One is virtical and the other is horizontal.

[alank46]

Hi
The wishbones each have 2 bushes and a ball joint, any or all of which can wear and cause an MOT failure.
Alan

I'm aware that the wishbone arm has a bush as part of it, but I've had both the offside and nearside front lower arm bushes split and this seems to be an MOT failure:

"Nearside front lower (rearmost suspension bush) bonded suspension unit bonding failed and part of unit is likely to become displaced [2.4.F.2].

So what's the difference between the bush in the wishbones and the one that makes you fail the MOT?

[Mr Hagon]

Hi
The wishbones each have 2 bushes and a ball joint, any or all of which can wear and cause an MOT failure.
Alan

I'm aware that the wishbone arm has a bush as part of it, but I've had both the offside and nearside front lower arm bushes split and this seems to be an MOT failure:

"Nearside front lower (rearmost suspension bush) bonded suspension unit bonding failed and part of unit is likely to become displaced [2.4.F.2].

So what's the difference between the bush in the wishbones and the one that makes you fail the MOT?

Yes, I see what you mean having hunted down a picture, either of the bushes can fail and need replacing, but it doesn't automatically mean replacing the entire wishbone, just the bush.

[Lazydocker]

Hi
The wishbones each have 2 bushes and a ball joint, any or all of which can wear and cause an MOT failure.
Alan

I'm aware that the wishbone arm has a bush as part of it, but I've had both the offside and nearside front lower arm bushes split and this seems to be an MOT failure:

"Nearside front lower (rearmost suspension bush) bonded suspension unit bonding failed and part of unit is likely to become displaced [2.4.F.2].

So what's the difference between the bush in the wishbones and the one that makes you fail the MOT?

Yes, I see what you mean having hunted down a picture, either of the bushes can fail and need replacing, but it doesn't automatically mean replacing the entire wishbone, just the bush.

Indeed... But replacing the bush requires a press capable of considerable pressure (10 Tonnes or so IIRCC) so replacing the complete wishbone is quicker (due to not pressing the bushes) and more reliable

[feeutfo]

Hi
The wishbones each have 2 bushes and a ball joint, any or all of which can wear and cause an MOT failure.
Alan

I'm aware that the wishbone arm has a bush as part of it, but I've had both the offside and nearside front lower arm bushes split and this seems to be an MOT failure:

"Nearside front lower (rearmost suspension bush) bonded suspension unit bonding failed and part of unit is likely to become displaced [2.4.F.2].

So what's the difference between the bush in the wishbones and the one that makes you fail the MOT?

Yes, I see what you mean having hunted down a picture, either of the bushes can fail and need replacing, but it doesn't automatically mean replacing the entire wishbone, just the bush.

Indeed... But replacing the bush requires a press capable of considerable pressure (10 Tonnes or so IIRCC) so replacing the complete wishbone is quicker (due to not pressing the bushes) and more reliable

pressing bushes in and out is not that simple as you need the correct drifts that fit the bushes to press onto, without these its very easy to damage the bush or the wishbone leaving the car stuck on a jack or lift going no where, avoid imo, unless your Mark dtm.

[Kevin Wood]

pressing bushes in and out is not that simple as you need the correct drifts that fit the bushes to press onto, without these its very easy to damage the bush or the wishbone leaving the car stuck on a jack or lift going no where, avoid imo, unless your Mark dtm.

Dazzler did mine with a 10 tonne press, IIRC and, at one point, I thought I was going to end up buying him a new one.

I think the distinction is that the front bush on the wishbone just gets a little sloppy when failed but doesn't obviously become unbonded (until you get it out and look closely). It also doesn't result in much deflection of the suspension when failed because of the geometry.

The rear bushes on the wishbone, however, directly locate the bottom pivot point of the suspension, so would probably regarded as hazardous at an earlier stage of failure.

Kevin

[feeutfo]

pressing bushes in and out is not that simple as you need the correct drifts that fit the bushes to press onto, without these its very easy to damage the bush or the wishbone leaving the car stuck on a jack or lift going no where, avoid imo, unless your Mark dtm.

Dazzler did mine with a 10 tonne press, IIRC and, at one point, I thought I was going to end up buying him a new one.

I think the distinction is that the front bush on the wishbone just gets a little sloppy when failed but doesn't obviously become unbonded (until you get it out and look closely). It also doesn't result in much deflection of the suspension when failed because of the geometry.

The rear bushes on the wishbone, however, directly locate the bottom pivot point of the suspension, so would probably regarded as hazardous at an earlier stage of failure.

Kevin

had a look under risky duckfeets omega the other day, one new wishbone drivers side with very soggy rear bush, and one old wishbone with ripped front bush pass side, which llowed a certain amount of towing out but minimised by a small plastic block thats set in to the centre bush on the inboard side thats there for that purpose. But the drivers side was so sloppy on it rear bush that the result was the complaint seen on here a few times, under braking the car pulls left (in this case) but stears right, and by stears right i mean the steering wheel actually turned to about 2'o clock position on its own, it pulled out of your hands while trying to keep the car out of the kerb, fine in a straight line, not too much tramlining, just comedy steering on the brakes.

I suggested a pair of lemforders fitted at wim as he lives round the corner and go from there, but understanding the error fully, well, for the steering wheel to turn right one(drivers in this case) wheel must be towing out but on the rear bush pushing the steering inboard from the drivers side, but with a tow out on pass side from the front bush more severe to deflect the car left, giving a pull left and a steered pull right. Wear evident on inside edges but could be a number of things in this case.

But point being although the front bush pass side was mullered the new rear bush drivers side was so soft it seemed to have more effect on steering pull feelingmat the wheel, while the front pass side seemed to pull the car more directionally. iiuc?

(goes to lay down with headache after so much thought in hot weather)

[Sixstring]

Had exactly the same thing on my pre-mot.

Changing BOTH wishbones the only true "sort" of the problem, and changes the tracking settings too.......when I removed the old ones, they didn't really look buggered, but, on closer inspection, both bushes were tearing and had marks on them, and after replacement, the effort and ride were considerably lighter and more positive.

Didn't think it was that bad before....
Oh, and for the cost of £15 or so, do the drop links too at the same time. Really makes a difference.

Mike.

[Mr Hagon]

I'm aware that the wishbone arm has a bush as part of it, but I've had both the offside and nearside front lower arm bushes split and this seems to be an MOT failure:

"Nearside front lower (rearmost suspension bush) bonded suspension unit bonding failed and part of unit is likely to become displaced [2.4.F.2].

So what's the difference between the bush in the wishbones and the one that makes you fail the MOT?

Things are slowly becoming clearer now, in that there are two bushes.  Will have to check the invoice to see what was done and ask the garage for more info.  Cost to fix was less than that of a gen GM wishbone, so what did they do and what did they change to get it to pass the MOT  :question

[feeutfo]

still not entirely clear what your asking tbh? seems we only have half the story? or is it me?

[Mr Hagon]

still not entirely clear what your asking tbh? seems we only have half the story? or is it me?

To explain in further detail, I've had both of the offending bushes replaced.  Having spent enough time on here I thought that the only proper solution was either a replacement wishbone or a poly bush with a ten tonne press.

But, having looked at a picture of a wishbone and seeing that it has two bushes that can potentially fail I'm purely curious as to how the bush can fail and a garage just doesn't say that a replacement wishbone is the simplest fix.  It looks like the offending part numbers on the invoice are 9156605/9156604 and cost around £15.

At the end of the day the car needs an MOT, but by virtue of being a member on here I'm taking more of an interest in what's hapenning to my Omega  .

[feeutfo]

 
But could it be that the garage is working to its own experience with general workshop practices on a wide range if cars.
What works on one car does not necessarily work on another, there are a few storys on here of bush pressing attempts failing as you'll notice that the edge of the front bush is extremely narrow with the centre spacer sitting proud.

This means a drift used must be within the 0.5 mm or so of the bush diameter with a recess in order avoid damaging the bush during fitting. Removal is not so critical as its buggered anyway.

WIM looked into pressing bushes but found the time taken to press bushes ment the it was cheaper to buy a pair of lemforders and fit those. A clue i think.

However, if you know of a place that can press bushes cost effectively then please let us know, we'll keep him busy i'm sure.

[Andy B]

  ...

This means a drift used must be within the 0.5 mm or so of the bush diameter with a recess in order avoid damaging the bush during fitting. Removal is not so critical as its buggered anyway. ......

I pressed out the old bushes from my Senator's wishbones. I had the facilities & materials at work at the time to make suitable tooling to press them out. But as you say, because these wishbones are only pressed fabrications and welded here & there, they are very easily bent. I'd to make do-nuts to go underneath to support the wishbone while I pressed the bushes in and out. That was years ago & the drifts & 'do-nuts' are long gone.