Smoke them tyres

The design of the diff mounting in our cars leaves a lot to be desired IMO. To me, I would fit nothing but the unvoided SuprPro bushes to give it the best chance it can get. It is good to see that all 3 bushes have been changed. If only the back bush is changed for poly, it will disproportionately load up the rear bolt and trash it (and/or the alloy rear case). Has anything been done to the blade link bushes? They are the sloppiest (most heavily voided) bushes in the whole rear setup. How they can have any hope of controlling axle wind-up is beyond me. They have the biggest input into controlling axle tramp. Once you see them out of the car and examine the rubber portion inners, it will be apparent how "loose" they are.

It's the front LCA bush primarily. All that is needed is a search!

Not suprised that it broke in that specific place. Stepping up and down in shaft diameters will lead to concentrations of load at transitions. A gentle radius/ramp, rather than a chamfer with an intersection "point", would have been a better option. Which is why the intermediate shaft broke, but the input shaft remained intact with a twist.

The issue is with harmonics. Have a read on the ATI balancer website. They can make custom items. http://www.dragzine.com/tech-stories/engine/tech-talk-the-ring%E2%80%99s-the-thing-%E2%80%93-inside-elastomer-engine-dampers/ The issue is that the flywheel has significant mass at one end of the crank, and the balancer is supposed to damp the harmonics at the other end. If it cannot, it just transfers it all down to concentrate at the back end of the engine, hence why the bolts will vibrate loose. The real loosening effect comes with different "orders" of harmonics colliding with each other. Some failure of oil pumps for our engines will have been contributed to by this. On the ATI website, it says some Honda engines have oil pump failures to due harmonics, and once an ATI balancer is fitted, the problem disappears.

A pic of the END of the broken bolt would be better. If it has "beach" marks of a gradual failure, or no beach marks of a sudden failure, will tell the story. The bolt plate may be more convenient, but there is a tendency in the industry to use "adequate" bolts in these positions....and then say installation is "easy". I would use at least a grade 8 bolt. Suspension and brake breakages/failures should be viewed with scorn as they are a direct car control issue.

That looks reasonably ok. I would keep an eye on the inner tyre wear as the km's go by.....as a check to see that the toe is suitable (and to make sure that a mechanically illiterate person has not changed it by running it up a gutter or something like that). If not, it will require more toe in as the bush issue has been resolved with the fitment of the poly bushes. The thing to remember with the fitment of the spacers at the front and rear of the UCA's is that the less spacers at the rear will give more caster (as the top ball joint is moved rearwards), but will also remove some initial camber at the rate of about 60% of the caster added. This is due to the rear portion/arm of the UCA being straight and it being brought more to a 90 degree position with respect to the vehicle centreline when more caster is added........so there is a trade off with the mix of shim stacks fitted on each control arm. IMO, it would have been better for Ford to have the straight portion of the UCA's on the front section, and the curved at the rear (or both straight ie triangulated). That way, when removing/lessening shims on the rear UCA mount point, it would add caster AND camber. I remain convinced that the upper control arms should be lower like the older Falcons as there is not so much angularity of the UCA required to get the same dynamic camber gain (UCA effectively shortens as suspension compressed, combating outward roll of UCA mounting point), and the instantaneous roll centre (theoretical intersection point of the UCA and LCA's) is in a higher position in relation to the fixed c of g. It also means less change in the instantaneous centre as the suspension compresses or droops. As far as I can see, the raising of the UCA is done to give more engine bay room. All the manufacturers seem to go with this style of double wishbone setup these days. But it is still a better setup than the Macpherson strut. You can see the difference in the Aussie ute series. The Falcons typically have about 5-8km/hr advantage in sustained corner grip over the Commodores....and would need less initial camber to do it (as the strut setup has no/very little camber gain provided by the LCA.....which is all unwanted "scrub" anyway). This will mean the tyre temperature for a double wishbone setup will be much more even across the width of the tyre.

Get the torque arm bushings replaced with poly bushes. That is where the lack of control is.

The fix is in the "Brake Shudder Issue" topic that is pinned to the top of this Brakes section.....37 pages is a bit long though. My reply is in there somewhere. To cut it short though....... The way to sort this is to change the front suspension bushes to polyurethane.....particularly the upper control arm ones. (although it would be best to change all of them in the front end....uppers and lowers). These poly ones have increased durometer (hardness), and more positively locate the suspension and resist fluctuation/pulsation under load. Once it starts under braking, it will continue until the minor oscillating load is released (which will be impossible given the softness of them). They are in NO WAY self damping. Basically, the rubber bushes compress and release with any small irregularity, either from any minor imperfection in disc runout or road surface. They are WAAAAAAY too soft. The wheel therefore experiences minor speed fluctuations with all this fore and aft flapping about, whilst the car experiences a more gradual load. The difference is the issue you describe. The FG ones are even voided on the front upper control arms. Introducing a failure point to "overflex" and tear. Hmmm. All in the name of a quiet ride. Unfortunately, ALL manufacturers are at it. Also, bushes can "look good" on the outside, but that tells you nothing of their ability to do the job asked of them. It just means they are not torn or perished. The lower control arm bushes symptom is increased inner tyre wear under braking (toe out under load). The upper control arm bushes symptom is brake shudder. If you can get a hold of the original bushes once they are removed, you will be surprised how soft and flexible they are. And this is meant to support a 1700kg car?????? Can all manufacturers please start to use a more technoligically advanced material.

Some of the higher pressures that they ask to run is to try to keep the tyre off it's outer edge IMO. Carcass flex is a real issue, and this is an attempt to combat it (at the expense of ride quality). I have dropped pressures down to that region, and have never had the tyre wear be unusual with it in lighter load use. I suppose the giveaway of the duress the tyre was under (principally the outer edge) was the understeer and accompanying sounds of protest. The area I look at is to see if the leading edge of the outer tread blocks is showing signs of tearing/chunking (or ramping). That to me indicates extreme concentration of down load on that point combined with side slip. The leading edge of each treadblock is the first one to see the cornering load........ -chunking equals geometry issues or point overloading (or low pressure) -"ramping" with a higher lip on the front edge indicates heavy braking as the tread block squirms under that load.....much like a knobby dirt bike front tyre ridden on the road. All in the "mix"..... Good to hear the progress your car has made. And for not too many dollars either.

Good stuff. The tyre wear should be much more even front to rear. Most of those expensive (european) cars are hugely overrated. 180k and no faster. Hmmm. What?.....180k and no fantastic brakes or adjustable suspension? No wonder they can afford F1 racing. And for such few mods to a great Aust car. Makes the dollar value of the others ill. I have fitted some custom King fronts that are halfway between std and the uprated Kings..... to me, they are made for the heavier V8. The heavier springs were certainly "working" on the wear rate of the current tyres. Still to do some further testing to form a solid conclusion. May move the front sway bar to the stiffer position and see how it responds to that. The ride on the street is MUCH better as an initial impression. Still as pointy in the front end, but tyre life should improve.

The cause of failure will be that stupid 5 cent roll pin that all driveline manufacturers have been using for years. The spider gear shaft hammers the hole oval in the carrier, and when it gets elongated enough going backwards and forwards, it breaks the roll pin. The spider gear shaft then wants to exit the carrier, and then all hell breaks loose in there as none of the internal gears are then held by anything. The "open" style carriers I have also never been a fan of....less metal to take the load and avoid distortion....and in such a critical high load area. If they want to continue to use this failure prone method of retention, they should AT LEAST beef up the thickness of the hole in the carrier..........so there is more bearing area, and thus lower the load per unit area. Give me a 9" anyday. Along with rubber suspension bushes, plastic items to do what metal should be doing, and roll pins in ill designed areas, are the stupidest items that all manufacturers continue to use....and will continue to create mechanical havoc in the future.

Insufficient grease........rather than actually wearing out.........is what kills them. The grease is also there to exclude water. Mine were showing distress at 30,000km. Pulled the arms away from the hubs and ran a grease needle UNDER the seal. Pumped about 5 or 6 pumps from the grease gun to fill each one. Working the grease around inside by exercising the joint will help also. This is the same reason ball joints usually fail. The other thing it does when it is full of grease is to stop the boots from collapsing, then creasing, and then tearing over time.....letting the moisture and dirt in.