Front wheel forked after track day today

[biggiles]

Had a great day on the track today, showing the Caterham chaps how do the straights!

Steering felt a bit woolly about lunchtime, and by the end any turning produced massive understeer and squealing. The wheels looked to be toe-ing out a couple of degrees, the car tended to the left and the wheel wasn't central. As the car was 4-wheel aligned last weekend, I thought perhaps a nut was loose and the tracking was out.

No, it wasn't that.

I drove home slowly, and an inch outside the garage, at home, the front left wishbone died.


We wondered why the front wheel seemed to have more metal bits floating around... those two bolts are now half-size.

More pics at www.flickr.com/photos/grcm/tags/wishbone/

Apart from feeling quite relieved at not dying at 120mph when the wishbone finally died and the weight of the car was supported by the fibreglass wheel arch (instead of 1mph in reverse), I now have a car on axle stands blocking the garage.

It's on gravel, so I can't move it anywhere.

Looks like a simple job of replacing the bottom front left wishbone. Are these the ones I see for 90 quid on various websites? Do I need "bushes" and can anyone tell me where I can find suitable bolts now that I seem to have driven through a couple :-)

I'm going to have to assume the brakes are OK until I can get under the car next weekend to have a look.

What could have caused this? Corrosion? bad driving? a pothole I didn't notice?

I changed the suspension myself a few weeks ago, encountering no problems - both wishbones looked (and felt) fine.

Is there any reason to change both wishbones at the same time, if the other one is in good condition?

[chassis 33]

From that first photo, it looks like the failure has been fairly ductile. also I note the coil overs look fairly new, are they uprated springs?

In my armchair pundit fashion, I'd say the wishbone had corroded an a particular area, casuing a weakpoint in the material, the extra forces of the trackday have caused the wishbone to fail at the point of corrosion then peel the rest of the material away. If the suspension is stiffer than OEM it would further exaggerate the forces on the wishbone leading to the failure.

I'd say change both lower wishbones, and give the rest of the car a bloody good going over too, wirebruse the other wishbones checking for any cracks or severe pitting and if found replace.

Regards
Iain

[hut49]

biggiles said:

Steering felt a bit woolly about lunchtime, and by the end any turning produced massive understeer and squealing.

I drove home slowly....

One word comes to mind...Plonker!

There's enough potentially lethal vehicles on the road in the hands of untaxed, uninsured unMOT'd idiots, without you (as a car enthusiast) adding to the statistics.

hope you get it fixed. I'd only replace the broken one - no reason to suspect a common point of failure.

[victormeldrew]

chassis 33 said:

... also I note the coil overs look fairly new, are they uprated springs? ...

Joo's Protechs, recently fitted, according to previous thread Were the shocks fitted correctly? No spacers omitted? I may be the angles, but on a couple of your pics it seems that there is a difference in the gaps between the shock and mounting lugs compared to the other side:


http://interweb4u.net/griff500/images

Edited by victormeldrew on Tuesday 8th August 00:10

[chassis 33]

From memory, Joo doesn't go too OTT on his road setups in terms of spring rate etc so no real need to panic there

To me, it does look like a corroded wishbone has let go and started to peel from where the metal ws weakest.

Regards
Iain

[biggiles]

hut49- I agree with what you're saying! If I had known at that time that it was more than just a tracking issue, I would have called the AA/RAC.

chassis33/victor - yes, you're right. I changed the springs/dampers a couple of weeks ago for Joo's Protechs, and did them correctly e.g.:


victormeldrew, I can't see the picture you've linked to - the link gives 404. When replacing the springs/dampers, we installed them in the same way as they had been before.

Thanks for all your feedback- looks like I don't *need* to replace both lower wishbones at the same time, but I should check the other one very carefully to see if there are any problems with it.

Edited by biggiles on Monday 7th August 23:26

[victormeldrew]

Try this link: http://interweb4u.net/griff500/images

I suspect the difference is down to camera angles, but it does look like there is less of a gap between shock body and mounting lug on the broken one.

[biggiles]

victormeldrew, those pictures are I agree slightly ambiguous, but the shocks are mounted equally each side. Thanks for asking.

So it looks like I need to buy a simple lower wishbone (90 + VAT), ask the local garage nicely to come and fit it and then drive it up on a ramp to get the rest checked out.

EDIT- do bushes normally come with a wishbone? or do I have to re-use the bushes?

Edited by biggiles on Tuesday 8th August 17:53

[Colin L]

As the cost of new bushes is cheap, do them when you replace that old wishbone, but looking at it in the pictures it may be wise to put on two lower wishbones if that one failed and the other one is the same age, it would do no harm and give you more comfort on the car's safety.

Also as the top wishbone on that side took must of the weight, have it checked out, it could be twisted from this incident, the shocks look very new so should be OK.

Get it checked by an expert,

Safety First, its your life and you only live once Mr Bond........

Colin L

[hugerr]

Another vote for replacing both lower wishbones, and having a very careful check over the rest of the car. Given that you use it for trackdays and, (presumably) fast road work -- when the suspension is being worked very hard and failure could easily be fatal -- it would be silly to try to save a few quid. It's only about the same as a couple of tanks of petrol, after all...

hugerr

[brummiewedge]

I am going to powder coat my front suspension over the winter, methinks i am going to brace it too in certain places, i was thinking of it anyways, but that is the decider!

[biggiles]

The work is all finished; I will be putting up some photos later on.

Interestingly, the other lower wishbone looks much newer and also much more sturdy. The one which failed was in far worse condition. It also seemed to be made of thinner metal. Perhaps the other one was replaced, but not this one... I need to check the receipts/history!

Check your wishbones!

[RedTuscan]

This incident must make you question whether your decision to take a 9 year old car onto a race track was wise.

I remember reading an article about Jonathan Palmer's place in Bedfordshire when it first opened. Were they not changing the brake discs (not pads) on the Audi TT's every day?

Tracks are hard on cars.

They have marshalls for track days, but do they have any doctors as no one is racing?

120mph crash does not bear thinking about.

[Seasider]

RedTuscan said:

This incident must make you question whether your decision to take a 9 year old car onto a race track was wise.

I have a 9yr old car & i can assure you its in better condition than a lot of much newer ones

RedTuscan said:

120mph crash does not bear thinking about.

I agree but failures can happen on any vehicle Edited to add: Or driver !!!!

Edited by Seasider on Tuesday 15th August 15:20

[biggiles]

Absolutely. Thank also of Goodwood and all the other vintage/classic car races and rallies.

I'm happier racing my 8 or 9 year old Chimaera than I would be driving some of the Fiestas I see dotted around the roads.

[shpub]

Not sure that is a corrosion failure - it is too clean. It is more like a metal fatigue failure. If you look at the wishbone it has been severely buckled with the loading on the wheel. As the wheel has been loaded and tries to move up towards the wheelarch, the wishbone would normally push against the spring and shock. In this case it looks like the resistance that they offer was higher than the wishbone could support and the wishbone has started to crumple at the shock mounting.

This could be caused by several things:

1. Too stiff springs.
2. Too stiff a damper setting.
3. Springs going coilbound.
4. Hitting potholes or going over curbs (Woodcote, Lavent Hairpin) come to mind. Repeated bashing can quickly cause metal fatique, especially if the suspension has little or no complience and/or is very stiff.
5. Component failure.
6. Wrong size damper that is too short.
7. Spring height too low so that the shock bottoms out first.

There are quite a lot of things to check out.

The wooliness was probably caused by the wishbone starting to bend and screwing up the alignment.

I would replace both sides as it is more than likely that the other side has been weakened. I would fit new bushes as well. I would also keep the old ones to show Joolz. Knowing his care for customers, he will certainly be interested in establishing what happened. If you haven't contacted him, I would do so as soon as possible.

Edited by shpub on Tuesday 15th August 19:54

[biggiles]

shpub, I live in the wilds of Wiltshire; the roads here aren't very good. At the moment, I believe this was caused by hitting potholes or ruts.

I've just uploaded my first video to "youtube" which should hopefully display in the window below:
<object width="425" height="350"><param name="movie" value="www.youtube.com/v/ucO7TbQsKZQ"></param><embed src="www.youtube.com/v/ucO7TbQsKZQ" type="application/x-shockwave-flash" width="600" height="350"></embed></object>

if not, www.youtube.com/watch?v=ucO7TbQsKZQ should take you to it. It's a short (1 minute) video looking at the break of the wishbone. There is also a tiny dent in the top wishbone but I am assured by multiple mechanics that it would not cause an issue.

I have also put up lots of photos at www.flickr.com/photos/grcm/tags/wi of the old and new wishbones, and the suspension setup at the front. They may be useful to people diong work on this area of the car.

[pink_floyd]

Thanks for the info, tried getting the bottom joint appart but it won't budge. I didn't realise that it was tapered, so proably need to hit it a bit harder. Out of interest how much was the lower wishbone, and did it come with the bushes included/fitted.

[biggiles]

pink_floyd said:

Thanks for the info, tried getting the bottom joint appart but it won't budge. I didn't realise that it was tapered, so proably need to hit it a bit harder. Out of interest how much was the lower wishbone, and did it come with the bushes included/fitted.

The lower wishbone came from TVR Power- I don't recall the exact figure but I think it was about 90-100. It comes with bushes.

The tapered joint is a real pain. If you can, leave it alone.

We eventually sorted it out using LOTS of WD40, gentle taps from a hammer and a jack pushing up.