Technical Suspension issues

[Popitinpete]

Changed the front shocks over Christmas and it was a b@stard of a job with the strut cap nuts and bearing retainer nuts proper seized. I don't have air tools and I destroyed most of my heavy tools!
On hindsight, I should have given the job to an independent garage.
Make sure you are proper tooled up!

Yea those top two nuts are the ones that make a fairly straight forward job a real pain without air tools and the correct deep sockets.

 

[DaveMcT]

I fitted new top bearing mounts, new bump stops and new struts.

The strut top nut on one side was solid but the other unscrewed with a deep dish ring spanner and allen key. I shifted the solid side by drilling the nut vertically alongside the thread so the threads on nut and shaft were cut. A cold chisel then loosened it. The spindle was of course trashed but it's scrap anyway.

 

[Pugglt Auld Jock]

Hi, if I understand your link correctly, torqueing the suspension bolts up when the car is on the floor and correct ride height makes a difference? Didn't think any 'movement' was in these fixings. How would doing it incorrectly effect the suspension bushes and ultimately their life span. I can see me getting the jack out....

If you consider the front suspension arm. The rear mount - usually the one which "goes" first can be tightened with the suspension in "droop" (ie still up on the axle stands) because this bush is not "twisted" by the action of the suspension. The front mount is a different story though. When you tighten the securing bolt then, of course, it "nips up" the inner steel sleeve of the bush so it can't rotate. So when you then put the vehicle back on the ground you are "winding up" the rubber of the bush which will cause early failure in service. So you can tighten the rear bush with the car up in the air but the front bolt should only be tightened with the suspension at normal static ride height. There are lots of situations where this "rule" applies, for instance "eye type" shock absorber mounts.

Folks who worked on the old Hydragas Leyland vehicles - Allegro, Princess etc - will be very aware that you had to tighten the rear radius suspension arm pivot bolt with the arm set very carefully to a precise height for just this reason. The rear suspension incorporated a very substantial rubber mount of this type. If the pivot was tightened with the suspension in full droop the rear of the car would ride ridiculously high because the "wound up" rubber of the bush affected the ride height. The outer rubber mount was well known for failing regularly and could be changed quite easily - rusty fixings allowing - by undoing the main pivot bolt and the two small bolts which held it to the body. Reassembly was just the reverse and within an hour at most you'd have fitted a new mount. The trouble was that to set the ride height properly you needed to decompress the hydragas suspension and set the suspension arm to the right height before tightening the big pivot bolt and you couldn't do that without the hydraulic pressurizing tool. When you knew about this it was a source of some amusement spotting these cars as you were driving around!

 

[Popitinpete]

If you consider the front suspension arm. The rear mount - usually the one which "goes" first can be tightened with the suspension in "droop" (ie still up on the axle stands) because this bush is not "twisted" by the action of the suspension. The front mount is a different story though. When you tighten the securing bolt then, of course, it "nips up" the inner steel sleeve of the bush so it can't rotate. So when you then put the vehicle back on the ground you are "winding up" the rubber of the bush which will cause early failure in service. So you can tighten the rear bush with the car up in the air but the front bolt should only be tightened with the suspension at normal static ride height. There are lots of situations where this "rule" applies, for instance "eye type" shock absorber mounts.

Folks who worked on the old Hydragas Leyland vehicles - Allegro, Princess etc - will be very aware that you had to tighten the rear radius suspension arm pivot bolt with the arm set very carefully to a precise height for just this reason. The rear suspension incorporated a very substantial rubber mount of this type. If the pivot was tightened with the suspension in full droop the rear of the car would ride ridiculously high because the "wound up" rubber of the bush affected the ride height. The outer rubber mount was well known for failing regularly and could be changed quite easily - rusty fixings allowing - by undoing the main pivot bolt and the two small bolts which held it to the body. Reassembly was just the reverse and within an hour at most you'd have fitted a new mount. The trouble was that to set the ride height properly you needed to decompress the hydragas suspension and set the suspension arm to the right height before tightening the big pivot bolt and you couldn't do that without the hydraulic pressurizing tool. When you knew about this it was a source of some amusement spotting these cars as you were driving around!

Yea makes sense on the front arm front Bush but I couldn't see what difference it made to the rear 'donut' Bush but it's not affected

 

[koalar]

this thread is getting overly complicated from the original poster point of view

They posted the car is wandering

I suggested an easy way to diagnose if the problem is the rear suspension arm rubber Bushes as 95% of the time this will be the problem

the reasoning in diagnosing the problem is these cars are cheap to run if you only change the worn out parts

The suspension arms are also an easy change three bolts and a hammer 5 minutes a side. So fingers crossed this will be end of it.

There is a small possible that the fault is the inner or outer track rod ends. Which is why I suggested diagnosing the problem first. You can fix any fault by changing everything but this can get expensive and its not the way I work. I like to diagnose and inspect as much as possible first then know the part I change will fix the fault I dont get it right 100% of the time but not far of

 

[Pugglt Auld Jock]

this thread is getting overly complicated from the original poster point of view

They posted the car is wandering

I suggested an easy way to diagnose if the problem is the rear suspension arm rubber Bushes as 95% of the time this will be the problem

the reasoning in diagnosing the problem is these cars are cheap to run if you only change the worn out parts

The suspension arms are also an easy change three bolts and a hammer 5 minutes a side. So fingers crossed this will be end of it.

There is a small possible that the fault is the inner or outer track rod ends. Which is why I suggested diagnosing the problem first. You can fix any fault by changing everything but this can get expensive and its not the way I work. I like to diagnose and inspect as much as possible first then know the part I change will fix the fault I dont get it right 100% of the time but not far of

You're right, we've done this to death here! Jack it up, give it all a good vigorous wiggle and just replace what's needed.

 

[DaveMcT]

A last comment (sorry) but it is relevant.
Get someone to put the car in first gear and move a couple of yards, then do the same in reverse. How much does the front wheel appear to shift Fore-Aft. Worn bushes are glaringly obvious.

 

[portland_bill]

Hi, if I understand your link correctly, torqueing the suspension bolts up when the car is on the floor and correct ride height makes a difference? Didn't think any 'movement' was in these fixings. How would doing it incorrectly effect the suspension bushes and ultimately their life span. I can see me getting the jack out....

As the suspension moves with bumps, the bushes flex. When the car is sitting normally, those bushes need to be resting, so not flexed either way. This gives them the longest life. If the bolts are tightened with the arms hanging, as the car is lowered, the bushes will flex, so further movement of the wheel upwards adds more to those already flexed bushes, straining the rubber, and can wear them out very quickly.
With the front arms, the rear bush bolt is vertical, so can be tightened however the arm is. The front bush, with the horizontal bolt, needs the car sitting normally.
Same with the rear suspension, including the rear dampers, final tightening should be done with the car sitting on its wheels.

On another note, from the thread above, the drop links have generally a short life. They can cause all sorts of strange knocking noises, but appear good when checked. Only when removed do they show their wear. If they have to be disturbed, and are more than a year old, always worth replacing to save hassle later.

 

[Popitinpete]

As the suspension moves with bumps, the bushes flex. When the car is sitting normally, those bushes need to be resting, so not flexed either way. This gives them the longest life. If the bolts are tightened with the arms hanging, as the car is lowered, the bushes will flex, so further movement of the wheel upwards adds more to those already flexed bushes, straining the rubber, and can wear them out very quickly.
With the front arms, the rear bush bolt is vertical, so can be tightened however the arm is. The front bush, with the horizontal bolt, needs the car sitting normally.
Same with the rear suspension, including the rear dampers, final tightening should be done with the car sitting on its wheels.

On another note, from the thread above, the drop links have generally a short life. They can cause all sorts of strange knocking noises, but appear good when checked. Only when removed do they show their wear. If they have to be disturbed, and are more than a year old, always worth replacing to save hassle later.

Hi bill, thanks yes I got it, I'm a technician of 30 odd years, I know about the bushes and flexing and positioning it was the rear doughnut Bush I was questioning, I could not work out why this was effected, as it happens its not,

 

[koalar]

again over complicated in my opinion.

the official instruction (I posted at the beginning of the now long thread) specifically ask for both bolts to be tightened with the suspension at the correct ride height

how hard can it be to do the job properly. Instead of second guessing why Fiat asked for it to be done this way. Both bolts are easily accessible with I standard ratcheting torque wrench and the car sitting on its wheels

proper arm, proper fitting equals 10 years or 100K miles for 5 minutes work. I am not bothered in trying to save 20 seconds.

 

[Popitinpete]

again over complicated in my opinion.

the official instruction (I posted at the beginning of the now long thread) specifically ask for both bolts to be tightened with the suspension at the correct ride height

how hard can it be to do the job properly. Instead of second guessing why Fiat asked for it to be done this way. Both bolts are easily accessible with I standard ratcheting torque wrench and the car sitting on its wheels

proper arm, proper fitting equals 10 years or 100K miles for 5 minutes work. I am not bothered in trying to save 20 seconds.

What's overcomplicated? Who's second guessing? It's a forum and subjects are up for discussion for anyone at anytime on anything they like. People can freely chip in on the subject. Do you just want the sole job of replying to people who ask for help ? Is it just your job? If so say so and we can all shut up.
You come across as upset that people are discussing a topic you replied to, seriously if you just want to be the one to answer the help questions please say so, what's the rules here?
Discussing the subject and passing around ideas will usually help to solve the issue and spread around knowledge, how can that be a bad thing?

Please in future refrain from trying to correct me or pass judgement, polite request here, I've been twirling spanners probably before you were born so please no more judgements, as I say, polite request.

 

[koalar]

I am not upset at all.

just the original question by the original poster is the car wandering what could be the problem be and now its getting messy and hard to follow and over complicated

I suggest a easy way to test for the rear bush. As this will vast majority.

Its not the only way. I am surprised someone hasn't suggested putting a lever between the subframe and the arm and wiggling. Which would be another way. But for some reason we have moved straight onto replacing the arm and then add other parts for good measure as well as discussing short cuts which in my opinion this is jumping the gun.

its nice to keep to the original post so when they read it back the replies are relevant

it could just as easy be inner track rods ends https://www.fiatforum.com/threads/front-wheel-alignment.482598/post-4564173

It wasn't me that came up with the procedure but Fiat I just blindly follow it for the sake of an extra 30 second. The rear doughnut Bush is the easier of the two to torque up with the car on its wheels as the torque wrench is horizontal to ground so you can get a nice long sweep.

Its the same recommend procedure for lots of cars. Your closing the gap of the subframe and trapping the Bush top and bottom. depending on fit and angle you will be altering the torque required.to achieve this I will stick to doing the job as Fiat intended and yes I have seen both the rubber mounts torn out, incorrect ride height due to preloading of the bushes and suspension bolts that have come loose because the Bush won't seated correctly before it was torque up mainly when the parts were changed at a quick fit type garage (just can't the right staff).

"Please in future refrain from trying to correct me or pass judgement, polite request here, I've been twirling spanners probably before you were born so please no more judgements, as I say, polite request."

not sure what my age, your age or how long you have been twirling spanners has to do with anything. If someone younger or older pointed out I was doing something wrong I would listen. I have also done many things wrong I try not to make the same mistakes again, that's how I learn. I dont care how anyone else repairs their car. If I see something I think is wrong I will say so. You are free to correct me I will not take offence, I am often wrong.

 

[Pugglt Auld Jock]

Hey guys, it saddens me to observe you guys getting upset about this. As Koalar says, if you follow the recommended procedure and only fully tighten the bolts when the vehicle is bearing it's full weight - so I would argue that you need to run the car back and forwards a couple of times with the bolts slightly slack, to properly settle the ride height, before tightening? - then you will undoubtedly avoid unnecessarily shortening the life of the bushes. However I think the value of in depth discussion, such as has been taking place here, is that a proper understanding can be achieved of how the component works on the car. ie that it's the twisting action applied to the front bush which is of most concern here and that the bush should be "relaxed" when the suspension is at normal ride height. It doesn't really matter if the suspension is at ride height when the rear retaining bolt is tightened. Although if you're going to delay tightening the front bolt until ride height is achieved then why wouldn't you just do the same with the rear bolt?

Like Popitinpete I too was a professional spanner twiddler for a large part of my earlier career and, personally, I like it when the discussion expands into related areas as often little snippets of very useful info spin off. I doubt if a week goes by without me reading something I didn't know on this forum. In this instance, if this conversation had not taken place, less experienced forum members would have understood that the suspension bolts should be tightened with the weight of the vehicle on the ground but not why this is important. So, personally, I enjoy absorbing the enormous knowledge base available here and the help and friendship of you all but I resist the temptation to "call out" anyone who I think is expressing an opinion I don't agree with, unless they are giving advise I think might be dangerous.
Kind regards to you all
Jock

 

[DaveMcT]

The bottom arms almost aways fail at the rear bush. This bush does not care what load is on the car because it works by flexing rather than twisting. Just fit and tighten the bolt. The from bush, which usually survives just fine, is supposed to be tightened in the neutral position - with load on the suspension. Simply leave it loose, then when the car is back on its wheels properly tighten the bolts with a ratchet and extension bar (bars).

 

[Popitinpete]

I am not upset at all.

just the original question by the original poster is the car wandering what could be the problem be and now its getting messy and hard to follow and over complicated

I suggest a easy way to test for the rear bush. As this will vast majority.

Its not the only way. I am surprised someone hasn't suggested putting a lever between the subframe and the arm and wiggling. Which would be another way. But for some reason we have moved straight onto replacing the arm and then add other parts for good measure as well as discussing short cuts which in my opinion this is jumping the gun.

its nice to keep to the original post so when they read it back the replies are relevant

it could just as easy be inner track rods ends https://www.fiatforum.com/threads/front-wheel-alignment.482598/post-4564173

It wasn't me that came up with the procedure but Fiat I just blindly follow it for the sake of an extra 30 second. The rear doughnut Bush is the easier of the two to torque up with the car on its wheels as the torque wrench is horizontal to ground so you can get a nice long sweep.

Its the same recommend procedure for lots of cars. Your closing the gap of the subframe and trapping the Bush top and bottom. depending on fit and angle you will be altering the torque required.to achieve this I will stick to doing the job as Fiat intended and yes I have seen both the rubber mounts torn out, incorrect ride height due to preloading of the bushes and suspension bolts that have come loose because the Bush won't seated correctly before it was torque up mainly when the parts were changed at a quick fit type garage (just can't the right staff).

"Please in future refrain from trying to correct me or pass judgement, polite request here, I've been twirling spanners probably before you were born so please no more judgements, as I say, polite request."

not sure what my age, your age or how long you have been twirling spanners has to do with anything. If someone younger or older pointed out I was doing something wrong I would listen. I have also done many things wrong I try not to make the same mistakes again, that's how I learn. I dont care how anyone else repairs their car. If I see something I think is wrong I will say so. You are free to correct me I will not take offence, I am often wrong.

Hey guys, it saddens me to observe you guys getting upset about this. As Koalar says, if you follow the recommended procedure and only fully tighten the bolts when the vehicle is bearing it's full weight - so I would argue that you need to run the car back and forwards a couple of times with the bolts slightly slack, to properly settle the ride height, before tightening? - then you will undoubtedly avoid unnecessarily shortening the life of the bushes. However I think the value of in depth discussion, such as has been taking place here, is that a proper understanding can be achieved of how the component works on the car. ie that it's the twisting action applied to the front bush which is of most concern here and that the bush should be "relaxed" when the suspension is at normal ride height. It doesn't really matter if the suspension is at ride height when the rear retaining bolt is tightened. Although if you're going to delay tightening the front bolt until ride height is achieved then why wouldn't you just do the same with the rear bolt?

Like Popitinpete I too was a professional spanner twiddler for a large part of my earlier career and, personally, I like it when the discussion expands into related areas as often little snippets of very useful info spin off. I doubt if a week goes by without me reading something I didn't know on this forum. In this instance, if this conversation had not taken place, less experienced forum members would have understood that the suspension bolts should be tightened with the weight of the vehicle on the ground but not why this is important. So, personally, I enjoy absorbing the enormous knowledge base available here and the help and friendship of you all but I resist the temptation to "call out" anyone who I think is expressing an opinion I don't agree with, unless they are giving advise I think might be dangerous.
Kind regards to you all
Jock

It was nothing to do with the bushes now jock, it's principle. I don't jump down any bodies throat when they are discussing any question posed, hence I don't accept it happening to me. Period. I've seen it happen to you, being told you're going off subject when you write one of your lovely detailed experiences or how you have overcome an issue, same with daveMct, he was told what he was saying was rubbish three times on a post the other day. Its all our forum, its all our help and it's all our contributions that keep it going. In my view As long as the initial question is answered to the guy or girl with the problem, a little discussion on the same subject can only help,its just spreading a little knowledge. That's it for me now, I'm saying nothing more on the subject.

 

[Myusername]

Thanks all, appreciate the valued input of all.