Technical Strut to hub nuts and bolts

[crad20]

I have to replace grande punto front springs. Will remove the 2x bolts and nuts that fix the strut to the hub at bottom. Anyone know if they have to be new nuts and bolts or can original ones be re-used? Torque settings would be useful too.
Thanks for any advice all.

 

[Ben D]

Reused mine, not sure about torque settings just now Haynes manual is in the garage.
I never reuse nylocs but anything else should be fine.

Needed impact wrench to get mine off

Cheers

 

[digger58]

I usually tighten to 1 good grunt

 

[aurick86]

Can be reused multiple times without any problems ( as long as they are not cress-threaded,, or have been damaged ..etc)

 

[Bernievarian]

Fiat recommend to replace them... Anyway, you can find here the torques.

Regards, Bernie

If someone helped You fix or understand your issue here, hit the thanks button, it's free !!

 

[digger58]

I've watched many mechanics work over the years and I can't recall any using a torque wrench on jobs like this. I certainly have never used one for general tightening, Yes for heads and preloads etc but not on general nuts and bolts.

 

[Bernievarian]

This time I can't agree with Digger ... Those bolts are actually fastening safety related stuff !

Tightening torque is not there just for fun, the goal is to stretch the bolt a certain amount so its internal tension can still increase/decrease without getting lose nor breaking under normal usage.
Too tight: the bolt can reach its elasticity limit and might break if stressed
Not enough tight: the bold could get lose, assembled parts get play, get worn etc.

Personaly I even torque my wheels bolts, but I must admit I don't use the torque wrench on every nut I see when doing general mechanic ;-)

Regards, Bernie

 

[crad20]

Many thanks. Think i'll play safe and get new bolts
cheers for the torque setting.

 

[Bernievarian]

Good decision, better be safe than sorry !
BTW, you will be amazed how little force you will apply compared to what you would without knowing the correct torque; bolts are often over-tighten. And remember the threads must be clean (no coper paste or other greasy thing). Also when you remove a nylock, nylstop or other shaped safety nut: replace it, they're single use.
Finally: I am NOT paranoïd ;-)

Regards, Bernie.

If someone helped You fix or understand your issue here, hit the thanks button, it's free !!

 

[g8rpi]

This time I can't agree with Digger ... Those bolts are actually fastening safety related stuff !

Tightening torque is not there just for fun, the goal is to stretch the bolt a certain amount so its internal tension can still increase/decrease without getting lose nor breaking under normal usage.
Too tight: the bolt can reach its elasticity limit and might break if stressed
Not enough tight: the bold could get lose, assembled parts get play, get worn etc.

Personaly I even torque my wheels bolts, but I must admit I don't use the torque wrench on every nut I see when doing general mechanic ;-)

Regards, Bernie

The bolt stretch is why they should be replaced. Just because the garage does not do it does not meant they are right. They get away with it because there is sufficient margin in the design to stop most immediate failures and by the time it does break you just blame it on the pothole, kerb or whatever triggered the final failure (that would not have happened if they used a new bolt and nut.
There is also the issue that these bolts generally have pre-applied screwlocking compound. This only works once. If you must re-use, at least clean them and apply suitable thread locking compound.


Robert G8RPI.

 

[aurick86]

Good decision, better be safe than sorry !
BTW, you will be amazed how little force you will apply compared to what you would without knowing the correct torque; bolts are often over-tighten.

If someone helped You fix or understand your issue here, hit the thanks button, it's free !!

Are you sure you read the actual torque before saying that?
They advise 10.2 daNm => 102 Nm, then 126Nm, then another 45 degrees.

120 Nm is a person weighing 120kg at the end of a 1m long braker bar

 

[Bernievarian]

Hi Aurick,

1 daNm is 1 kilo over 1 meter, so 10.2 daNm is 10.2mKg ....

Would YOU stand over a one meter bar to tight those poor M12 bolts (+ 45° !!) ?
Do you easily find such a torque wrench in Roumania ;-) ?

Regards, Bernie

If someone helped You fix or understand your issue here, hit the thanks button, it's free !!

 

[g8rpi]

Are you sure you read the actual torque before saying that?
They advise 10.2 daNm => 102 Nm, then 126Nm, then another 45 degrees.

120 Nm is a person weighing 120kg at the end of a 1m long braker bar

I think you missed a decimal place,
a Newton is 0.102kg under normal gravity so that is only 12.24kg at the end of a 1m bar.

Robert G8RPI.

 

[aurick86]

g8rpi @ Bernievarian
Thank you for clearing that up!

That makes a lot more sense.

 

[Bernievarian]

@ Aurick : Cu plecere ;-)