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How to best to reattach a MacPherson strut?

Hi,

I have a Fiat Punto 1.2 8v (2000). I've replaced one of the front MacPherson suspension struts, but it wasn't quite as straight forward as the Haynes manual (or even the workshop manual) suggested.

You're instructed to remove the two bolts and nuts at the base of the suspension strut to the top of the swivel hub. You are then told to pull the swivel hub outwards at the top to release it from the suspension strut.

Sounds simple enough. On my first attempt, when I removed the two bolts, the base of the suspension strut rapidly forced itself down into the CV Boot (I suspected this might happen as it is a big spring ;). Unable to move the firmly wedged strut from the CV Boot. I ended up using a long piece of wood with a jack on the base which the spring is sat on. This pushed up the strut enough to move to the side and then remove.

Reattaching proved a little tricker.

Same thing really but in reverse. Haynes and the workshop manually just advise to engage the lower end of the strut with the swivel hub and fit the bolts. 1 jack, 1 long piece of wood, many failed attempts which resulted in the strut banging the drive shaft or CV boot and 30 minutes later, I'd managed to complete this simple step.

I'm guessing this is all down to technique, or I'm just missing something obvious. The strut sits about 2 inches lower than the swivel hub with the bolts removed. The only way I can attach is by compressing the spring using the wood and jack technique above. Both manuals only suggest using the coil compressors after the strut has been removed. Attempts to use them with the strut in place didn't really work, as they were only millimeters away from the top of the wheel arch before I started compressing. A few turns later and I was pushing into the metal.

You may have noticed I said first attempt. When I'd completed all steps and was tightening the suspension strut upper mounting cup retaining nut. The hex hole for the Allen key to counter hold the piston rod while tightening shattered. I'd only just got it to pinch tight and was just about to try and add a little extra presure. The Haynes manual suggests 60nm torque. I'm not sure how to measure the torque with a deep offset ring spanner. But I hadn't really got any further than when it just pinched. Faulty part or should this nut not be tightened beyond when it first pinches?

Thanks for any help,

Tim

Reply to
Tim
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I presume you removed the lower arm to allow the hub assembly to lower down, removing the torsion from the spring? I'd have ....

  1. Removed lower arm pinch bolt
  2. Removed lower arm from hub assembly (heavy downward force on arm causing it to pop out, hub and strut move free(er) than usual).
  3. Started removing strut from hub.
Reply to
Sandy Nuts

P.S You'll need to find a method of supporting the weight of the entire hub assembly. Do not allow the weight to be carried by the brake line or angle it enough to piss off the CV joint.

Reply to
Sandy Nuts

yep thats one way, normaly though i just use a pry bar to force the lower arm down to take the strain off. to be honest you couldnt find an eaiser strut to change.

Reg

Reply to
kronenburgh

Thanks both for the reply...

I must admit, 15-20 minutes into trying to jack up the strut without it springing off my bodged compression job. I was beginning to consider if this step was required. The Haynes manual and the workshop manual make no reference to removing the lower arm. I was wondering though if I would suffer from the same or similar problem, even if I removed the arm. Because the strut naturally sits 2 inches below the swivel hub alignment bolt holes. But as I don't yet have a ball joint separator tool, this option was out.

Ordinarily not a selling point for a car. But the Punto has a small 8v engine which has plenty of space around it. As it's light, these parts are easy to change. I don't think it's difficult, but with nobody to reference I don't think I have the right technique. I'm guessing if you're using a pry bar, you must be getting leverage against something. Is this the lower arm? I mentioned above that the lower strut and lower arm are about 2 inches out from each other. If I can force the lower arm down an inch or two I could easily align the holes and jack the rest. I don't know how far (if at all) the lower arm can be forced down.

Thanks for the advice,

Tim

Reply to
Tim

You are jacking both sides of the car up arent you, otherwise the anti roll bar will make life difficult.... lou Bricant

Reply to
Lou Bricant

What you and the book of lies missed out was. After jacking, supporting car and removing wheel, fit spring compressors to prevent strut extending.

Before fitting new strut, compress spring using spring compressors to reduce strut to instaled length.

-- Peter Hill Spamtrap reply domain as per NNTP-Posting-Host in header Can of worms - what every fisherman wants. Can of worms - what every PC owner gets!

Reply to
Peter Hill

I thought that might be the case. A few guys at work had suggested this. I found when I was compressing that I didn't have enough space within the wheel arch. I'll give it a try when I replace the other side.

Regards,

Tim

Reply to
Tim

No I'm only jacking up one side. This means more weight than usual is rested on the other wheel. I'll dig out the Haynes manual again and have a look at the anti roll bars and how they work. I'm guessing that both sides must be inter-connected based upon what you're saying. Looking at step 1, it does state to jack up the front of the car and rest on axle stands. Because I'm only working on one at a time, I just jacked up the side I was working on only.

Regards,

Tim

Reply to
Tim

I've yet to use a ball joint seperator to remove a lower arm. My right foot usually does the job.

Reply to
Sandy Nuts

I found this on

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"When you go into a turn now, the front suspension member of the outside of the turn gets pushed upward. The arm of the sway bar gets pushed upward, and this applies torsion to the rod. The torsion them moves the arm at the other end of the rod, and this causes the suspension on the other side of the car to compress as well. The car's body tends to stay flat in the turn."

By only jacking up one side, I guess the compression of the spring on the opposite wheel is compressing the spring I'm working on. Which probably explains why I have to jack the spring up by 2-3 inches to try and get it in place (not much fun). I look forward to trying this when I get my replacement shock.

Thanks for the tip.

Tim

Reply to
Tim

Not knowing what a ball joint was a little while back, I thought this tool might be complicated or cost a bit. I was quite surprised to see it was just a simple fork type tool you hit with a hammer (though I thought that would stress the joint a little). I've seen a slightly more up market version, that appears to have a bolt at the top. I guess this does some of the prying action for you.

After forensic examination my Fiat dealer has said they will replace the shock with the damaged counter hold section. I was quite surprised, even though it did shatter under little pressure, it's a hard case for a customer to argue.

When I get the new shock I'll try fitting with the front of the car raised (not just one side). I'll report back if it was easier. If not, when I do my other Punto that ball joint separator may be an attractive option.

Tim

Reply to
Tim

Well that was a completely different job. After jacking up 'both' sides of the car, when releasing the bottom bolts the shock only dropped

1-2cm. When I had only jacked up one side of the car the shock dropped 1-2cm below the drive shaft. Removing and putting back in place was easy.

Thanks for the tips,

Tim

Reply to
Tim

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