Technical suspension arms what we know or don't

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Technical suspension arms what we know or don't

koalar

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original arms are normally superior and often last 10 years or over 100K miles
the casting for the 100HP is identical to the 1.1, 1.2 and 1.3D only the bushes are different.

ebay aren't the most reliable place to buy from. OEM or original are often stated in the advert but rarely are
paying more don't mean your buying better quality

some of the differences between original and some copies.
Ball joints can be substandard, some only last just over a year
the ball joints don't fit the same. Original you can just push up and fit the pinch bolt. Third party you can pass the groove and requires a bit of jiggling to fit the pinch bolts
rubber bushes maybe of a poor quality, again only lasting just over a year
a big give away of a "fake" part is if you compare it to an original. The original has crisper edges and a finer surface texture.

I don't buy original but from a local motor factor (C.E.S). They supply to the motor trade. Not the absolute cheapest but you get an easy 3 years out of them


Symptoms of a bad arm

vague steering
feels odd when going over cats eyes or rumble strips
if there is a groove in the road it kind of gets stuck in it
wandering on the motorway, worse when windy
my favourite, I change mine when parking the car and its on full lock. You can feel it turn slightly tighter. It is very subtle
clunking noise over bumps sometimes felt through the floor pan, Again subjective as the drop links give a lighter jiggly sound

testing the arms
inspect as much as possible the rear rubber if are lucky you might spot it perished in which case you don't need to go any further
Jack up the car, wheel still on. steering lock on, place an inspection light on the rear Bush. put your knees on the outer edge of the tyre at 3 o'clock and 9 o'clock position. Now put your hands opposite the knees, on the inside. Now pull with the right hand and push with the left knee while looking at the Bush. Then reverse pull with the left hand and push with the right knee. If there's more than a 1mm of movement its probably time to replace
While there is worth testing the drop links. There not as easy to test but there should be no push pull movement when they aren't under tension. Normally if they arnt jiggling over cobble roads they have at least a year or two left.

another test is to put a lever between the subframe and arm and wiggle it about. This is subjective and you need to know what a Good one feels like. You can compare the off side to the near side

there are other ways and I leave it up to others to expand and explain testing the ball joint

changing
Its best to spray the bolts a few times with penetrating oil a few day before doing the job
Loosen the wheel nuts. This can be the hardest part if the wheels haven't been off recently. I have just done one that required a 6 foot pole
stay safe. I jack under the suspension arm rear bush with a wooden spacer. Then use an axle stand and wooden space under the proper pad. I also put the wheel at the front as extra precaution.
its just a matter of undoing the three bolts and bash the ball joint off. At least 2.5lb hammer. There's no point I messing around. the parts scrap anyhow. I have seen someone open the pinch bolt slit up with a chisel to make it easier to knock out. It makes sense although I have never had to do it.
You absolutely do not have to undo the drop links to do this job. It doesn't give you any more room, If you are jacking one side at a time it give you less, maybe I am messing something here. Unless you need to change them I would leave them well alone. Let me explain. Depending on brand you may or may not have something in the centre to stop shaft from spinning. Even if there is there is something it will more than likely round out before you get the nut off. Unless you fitted them they will almost certainly not have any anti seize on them and after two years of salt here in the UK the thread will be quite messed up. You can't use heat the nut is a nylon lock nut and melting will make it worse. The option for people without proper impact drivers are. Hacksaw, grind, chisel or nut splitter. Once you done one nut its not going to go back you might as will cut the other off. The whole job of changing an arm is around 5 minutes a side. Changing the drop lines without proper tools is going to add at least 10 minutes per side

a punch is nice to drive out the pinch bolt out. I wind the nut to the end to protect the thread and knock it until it bottoms out. Depending how corroded it will either fall out or need to be drifted out.

pretty much everything in the video is correct. both Bush bolts should be torqued up with the arm at its correct ride height. I just do the bolts up with the car on the ground. The rear one is very easy. The front is pain with my torque wrench, it doesn't quite click onto the position. Its not far off so I just lift the car a few mm with my knee. I will warn you that the torque setting for the pinch blot is wrong in some Haynes manuals but has now been corrected I believe.

I also always fit the pinch bolt with the nut to the front. From new every one is fitted this way round. No idea why as its counter intuitive. However Fiat have fitted tens of millions this way and replaced 100 of millions of arms this way, their instructions also show it this way round.

I have purposely missed some things out so it open to discussion

 
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The Original Birth bottom arms from Shop 4 Parts were painted and clearly better made than the arms we took off my brother's Panda.
£41.40 each vs £25.55 from GSF Car Parts but I think money well spent.

The latter on eBay looks to have the same type of (two spoke) rubber bush that had failed on brother's car.

The ball joint rubber boot is easily damaged. You can get replacements for not much money but be careful.
 
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Contamination.

Not sure why but engine oil destroys some rubber mounts

takes a fair bit but WD40 both swells the rubber and makes it go softer

I never used it but there is a spray that seals rubber bushes. Guess it might improve the life of the super cheap arms ?

does depend on the type of rubber the bushes are made from but, oil, petrol, anti seize, grease and so on will effect some bushes life.
 
Contamination.

Not sure why but engine oil destroys some rubber mounts

takes a fair bit but WD40 both swells the rubber and makes it go softer

I never used it but there is a spray that seals rubber bushes. Guess it might improve the life of the super cheap arms ?

does depend on the type of rubber the bushes are made from but, oil, petrol, anti seize, grease and so on will effect some bushes life.
Oil will always damage ordinary rubber. WD-40 is supposed to be safe but even if it is questionable, the stuff does evaporate quite quickly and is good for cleaning spilled oil off any rubber. That's said, oil getting into a suspension bush would probably ruin it. But it would have to be one heck of a leak to get that far back.

The (probably) super cheap rubbers on brother's replaced arms were clean but thin and weak looking compared to the O-B items we fitted. I think they failed from being too weak to do the job. Buy cheap. Pay twice. If you fit decent quality arms, the bushes can eventually be replaced for not much cost (you need a press tool) and worth doing as the ball joints will also be better quality.

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