suspension arms what affects there life

part numbers, driving style, vendors and so on.

eBay, motor factors, driving style, Bush types, speed humps and so on.


I have just replaced some arms on a I10 the ball joints had failed after 132K


I have had a Panda that had every invoice and receipt. That had neatly 200K on the clock. But no receipt or invoice for arms. I replaced them and they were still like new 4 years later. I accept there could be a missing receipt but doubt there would be two missing thats still 100k (miles)


I never replaced the arms on my other Panda in 4 years. This car was driven carefully but in very tough conditions. Once a month it would drive several miles down farm tracks and often across fields.

there are several post and threads at the moment where they haven't lasted.

I have had cars in the past where the rubber bushes didn't last. A Sierra was a yearly change around 20K. But I thought those days had gone ?


I have replaced the ones on an A-class due to a small engine oil leak damaging the rubber


I always do the final tightening at normal ride height.


obviously something is going on. I know speed humps kill the tyres on small delivery van that are loaded


It would make sense if the problems are due to poor quality bushes ?? but have no proof


Before eBay and parts were via a motor factors you could guarantee the old and new would be identical and no alignment would be required.


I have probably missed some variables out.

I'll be doing the arms on our Panda this weekend, your recommendation is to nip everything up, then lower the car off the jack and then tighten the bolts up correctly whilst the wheels are fully on the ground?

correct

koalar said:

I have had cars in the past where the rubber bushes didn't last. A Sierra was a yearly change around 20K. But I thought those days had gone ?

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I had a mondeo that needed an annual MOT along side it’s regular suspension arm replacement, every MoT one of the rubbers had ripped or torn.

The mk2b 2004 Punto I had lasted 100k miles before I changed them and that was because the ball joint rubber had split and grit had killed the ball joint all the other bushings where fine, I’m sure Ford used the cheapest crap ever to make suspension arms.

I forgot about my Punto


seems to 100K-200K is possible on the original arms



that leaves either a fitting problem or the quality of the 3rd party parts or both.

be interested from people who had there car from new or nearly new.

I have a theory regarding these.

Drivers of larger, wider track cars tend to straddle those square traffic calming humps and skim them at speed.

The suspension is designed to cope with mainly flat surfaces with some small camber and some ups and downs, basically like this l--l.

What you are effectively doing skimming these humps is forcing it to run like this \--/ over them.

Introducing such a large camber and a lateral force to each wheel can't be good for suspension and the weak point is the bushes as they will compress and stretch before the metal in the arms.

Drivers in smaller, narrower track cars and low slung stuff tend to have to slow down and ride the humps with one side of the car. This just causes the wheel/suspension to go up and down that side and it's not dealing with such large camber angles.

koalar said:

be interested from people who had there car from new or nearly new.

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Panda owned from new, original arms still good after 100k/10yrs.

One thing that will put significant extra stress on the arms is any out of balance forces coming from the wheel/tyre combination, so if your car isn't wearing the front tyres evenly, the arms may not last as long. For any given mass imbalance, narrower tyres reduce any out of balance forces, so running wider tyres than the standard 155's will also tend to reduce suspension component life.

Your chosen cruising speed on longer journeys will play a part in this also.

Generally speaking, the harder the car is driven, the more likely parts are to wear out prematurely.

Goudrons said:

I have a theory regarding these.

Drivers of larger, wider track cars tend to straddle those square traffic calming humps and skim them at speed.

The suspension is designed to cope with mainly flat surfaces with some small camber and some ups and downs, basically like this l--l.

What you are effectively doing skimming these humps is forcing it to run like this \--/ over them.

Introducing such a large camber and a lateral force to each wheel can't be good for suspension and the weak point is the bushes as they will compress and stretch before the metal in the arms.

Drivers in smaller, narrower track cars and low slung stuff tend to have to slow down and ride the humps with one side of the car. This just causes the wheel/suspension to go up and down that side and it's not dealing with such large camber angles.

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going up and down curbs and missing speed bumps with one wheel does kill drop links quicker.

jrkitching said:

Panda owned from new, original arms still good after 100k/10yrs.

One thing that will put significant extra stress on the arms is any out of balance forces coming from the wheel/tyre combination, so if your car isn't wearing the front tyres evenly, the arms may not last as long. For any given mass imbalance, narrower tyres reduce any out of balance forces, so running wider tyres than the standard 155's will also tend to reduce suspension component life.

Your chosen cruising speed on longer journeys will play a part in this also.

Generally speaking, the harder the car is driven, the more likely parts are to wear out prematurely.

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thank you

as I suspected. Most of the short life is either how we fit them or the quality of eBay parts. Even driven hard its not going to be half 5 years is still acceptable

an oil leak reaching the bush will destroy the rubber. Been there although not on a Fiat

just need to find out how they are dying in 12 months ??


I use a bit of lithium grease on the bolts. I wonder if other greases damage the rubber ?? the same as oil

Most greases will damage rubber, but the suspension bushes have a steel tube insert so no worries if you use stuff to stop threads seizing.

I think the problem is the bush lies at 90° to the suspension movement. It's like that to absorb road bumps as they try to push the wheel backwards but the rubber gets stretched and compressed over every ripple in the road.

Two bushes like the front one would last better, but then you'd need a thrust bush to deal with braking and bump forces. Fiat (and everyone else) do it with one vertical spindle bush as it's cheaper.

DaveMcT said:

Most greases will damage rubber, but the suspension bushes have a steel tube insert so no worries if you use stuff to stop threads seizing.

I think the problem is the bush lies at 90° to the suspension movement. It's like that to absorb road bumps as they try to push the wheel backwards but the rubber gets stretched and compressed over every ripple in the road.

Two bushes like the front one would last better, but then you'd need a thrust bush to deal with braking and bump forces. Fiat (and everyone else) do it with one vertical spindle bush as it's cheaper.

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The point was the originals last 10 plus years and 100K plus miles so there is nothing wrong with the design

Replacements have been failing in less than a couple of year.

Is it something we’re are doing wrong or substandard parts

I fitted arms to both my panda and punto and they lasted well. But I didn’t buy them on eBay and tightened them at proper ride height.

"It should be remembered that this operation is vital to ensure the correct operation of the front suspension and prevent premature damage to the track control arm rubber bushes."

Would explain some of the failures.

But I suspect the ball joint failures are poor quality parts being supplied

To be fair, my girlfriends car is driven quite hard. She doesn't bang up curbs or anything, but we do hang it round corners most of the time as it does handle pretty well.

I think it's mostly poor quality parts, but the price varies so much and half the time it's the same crap stuff irrelevant of the price.

The Original Birth bottom arms I recently fitted to my wife's 1.2 came from Shop-4-Parts. They cost a bit more than eBay but are more likely to be decent quality. Don't forget to get new pinch bolts
https://www.shop4parts.co.uk/?name=store&op=Product&ProdID=2267

Does anyone know the outer diameter of the rear rubber bush so we can get the kit ready to fit new bushes to used arms.
https://www.shop4parts.co.uk/?name=store&op=Product&ProdID=13528

DaveMcT said:

Does anyone know the outer diameter of the rear rubber bush so we can get the kit ready to fit new bushes to used arms.
https://www.shop4parts.co.uk/?name=store&op=Product&ProdID=13528

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be careful with this. i have found that the rear bush OD can vary enough that you either need to skim a little off the bush or add some extra metal to get the diameter correct.

its only minimal (a mm or so) but it is something worth being aware of.

dac69er said:

be careful with this. i have found that the rear bush OD can vary enough that you either need to skim a little off the bush or add some extra metal to get the diameter correct.

its only minimal (a mm or so) but it is something worth being aware of.

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Typical. The "perfect" fix isn't after all.

DaveMcT said:

Typical. The "perfect" fix isn't after all

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Much as I believe in and applaud only replacing what is actually worn out, I don't recommend trying to replace these bushes without access to proper engineering facilities; you need a hydraulic press and the appropriate mandrels to do the job properly. The job is made more difficult by virtue of the rather obvious fact that you can't use heat to help with fitting the new bush.

If you can fit the new bushes into used arms using only a hand vice, the OD of the bushes is probably too small for a proper interference fit.

I've seen improperly fitted ones worming their way out in service; it's quite a common MOT failure.

You'd also be well gutted if you spent half a day improvising tools to get one in perfectly, only to have the bottom ball joint fail a month later.

Been there, done that - though not on a Fiat.

its only recent that complete arm have become a cheap cost option


I have changed dozens of bushes over the about 15 years. The only one I have changed recently was for a Mercedes due to cost


never had one not fit.


Not having a press the only way I have found to remove them is to chain drill the rubber centre out. Then chisel the aluminium shell out. The new ones tap in fairly easily. Seen people use homemade jigs using threaded bar but I just use a large socket and a club hammer

bushes should always fit unless substandard or wrong part used

koalar said:

never had one not fit

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You've been more fortunate than I.

Sometimes parts are produced with small, known variations in size and are selectively assembled in the factory when a precise fit is required; I've often wondered if that was the case with these bushes.

And yes, if an arm cost £100's and bushes a fiver, then I'd probably eat my words and have a go myself; but thankfully that's not the case here, except for those models with bi-Xenon lighting which have arms tapped for levelling sensors.

koalar said:

bushes should always fit unless substandard or wrong part used

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Sadly the world in general, and ebay in particular, is full of substandard and wrong parts; a problem by no means limited to suspension arm bushes.