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Hi, I am in the process of changing the rear shocks on my NA8. I want to keep the feel of the car stock so I went with KYBs.

I followed some great instructions on the web and lo and behold the driver's side shock is already replaced. I did hit one snag. I rounded the nuts that hold the damper and spring assembly to the shock tower and now cannot torque them enough.

What is the general advice. Should I just go with any nut that fits or should i find Mazda nuts. They are a regular 14mm hex with a collar. I am leaning towards just finding any reasonable grade nut.

What would the experts do.


If you are wondering why I am replacing the shocks, well the car was beginning to bottom out in the rear a bit too easily and going around sharp corners it was rolling in the rear a bit too much.

So far I think the fronts seem OK in comparison but when I get the time I'll probably swap them over as well.

Go buy the correct nut. IF looking for a cheap option. Go to a wreckers and hope to heel the shocks are still attached.

I hate to disagree with pjr, but those nuts are under very little stress. Any decent nut with the right thread pitch will do fine (have you seen the crap nuts some coilover manufacturers supply with their units? I won't name names, but...).

Next time, use the right tool for the right job. 6 point deep sockets!

zossy1 wrote:I hate to disagree with pjr, but those nuts are under very little stress. Any decent nut with the right thread pitch will do fine (have you seen the crap nuts some coilover manufacturers supply with their units? I won't name names, but...).

Next time, use the right tool for the right job. 6 point deep sockets!

That is the point I did use the correct deep sockets. Its almost like the nuts had gone soft or something.

I wont drive the car until I have the right nuts installed. I tend to think hardware is all specs. Would they be high strength steel?

snshami wrote:I rounded the nuts that hold the damper and spring assembly to the shock tower and now cannot torque them enough.

I don't get it;
Do you mean the THREAD on the INSIDE of the nut is worn? or is the thread on one of the two bolts on the damper top-hats worn?
When you stated "rounded the nuts" this means you've worn off the OUTSIDE edges of the hexagonal.

If it's an issue with the thread on the nut, then as mentioned, simply buy any decent locking nut, ie. a nut that has a flange on one end. Bring it with you to your nearest hardware or Supercheap.
If it's an issue with the bolt then the easiest option is to buy another top-hat.

And as mentioned, don't go torqueing them too tight as all they really need to do is locate the top-hat bolts so they don't move laterally.

Do them up with the suspension not loaded, go for a drive, then double-check them and re-tighten if necessary.

1red5 wrote:

snshami wrote:I rounded the nuts that hold the damper and spring assembly to the shock tower and now cannot torque them enough.

I don't get it;
Do you mean the THREAD on the INSIDE of the nut is worn? or is the thread on one of the two bolts on the damper top-hats worn?
When you stated "rounded the nuts" this means you've worn off the OUTSIDE edges of the hexagonal.

If it's an issue with the thread on the nut, then as mentioned, simply buy any decent locking nut, ie. a nut that has a flange on one end. Bring it with you to your nearest hardware or Supercheap.
If it's an issue with the bolt then the easiest option is to buy another top-hat.

And as mentioned, don't go torqueing them too tight as all they really need to do is locate the top-hat bolts so they don't move laterally.

Do them up with the suspension not loaded, go for a drive, then double-check them and re-tighten if necessary.

I rounded the outside edges of the hexagonal. I realise now that they are locking nuts. They are squished at the top.

Did you say that Supercheap has hardware?

Supercheap has a rotating display that have pretty much all the common nuts and bolts for automotive. It has bolts & nuts attached to the display so you can bring your bolt or nut and ascertain the corresponding size and thread, then all you do is find the style of nut or bolt that is suitable for your application.

The middle nut which fastens the shock/spring to the top hat is under low stress. The OEM nut is torqued to about 28-35ft/lbs, and many aftermarket are between 10 and 25 ft/lb.
I'm surprised the shocks didn't come with centre rod nuts and spares with the instructions for torque settings etc.

I wouldn't waste time faffing around at wreckers. They're a pretty common part, it's just a standard collar self-locking nut.
If anything I'd drop down to your local dealership/mechanic or repco/supercheap with the dud nut and see if they have something there. I really doubt it'd need to be HSS, but it won't hurt.

You may have noticed when you pulled the old shocks, the hole in the middle of the top hats are D-shaped to prevent the shock rod from spinning while you torque down the centre rod nut.
Are the KYB's the same, or did you have to do drilling? Bear this in mind when you are torquing down the centre rod nut. If you see the top hat twisting, stop immediately and seek further advice here before proceeding.

It must be painful working on a car and being challenged by such basic things. If a nut or a bolt etc is faulty just replace it- these days its so easy. There are many sources for components including specialists- eg Bursons/ shocker suspension fitters/ bolt suppliers/ Mazda etc. Car makers always try to standardise on fasteners to avoid tooling up non standard items. You take the component along if necessary for comparison -Just take some initiative on the small stuff.

Mr Morlock wrote:It must be painful working on a car and being challenged by such basic things. ...

You got out of the wrong of the side of the bed again this morning

Wivvix wrote:
You may have noticed when you pulled the old shocks, the hole in the middle of the top hats are D-shaped to prevent the shock rod from spinning while you torque down the centre rod nut.
Are the KYB's the same, or did you have to do drilling? Bear this in mind when you are torquing down the centre rod nut. If you see the top hat twisting, stop immediately and seek further advice here before proceeding.

The KYB shaft is D shaped as well so it was a good fit.

snshami wrote:

Mr Morlock wrote:It must be painful working on a car and being challenged by such basic things. ...

You got out of the wrong of the side of the bed again this morning

the 'good-side' of his bed is against a wall...

I agree with Morlock.

Dann

The two nuts that attach the shock assembly to the car are deformed so they don't work themselves loose. Same on the fronts. I would suggest replacing them with a similar type of fastener and/or use thread locker.

NitroDann wrote:I agree with Morlock.

Dann

To a certain extent he is right, of course. It is a pain to work on a car because everything has to be thought out and analysed. Thats because nothing comes naturally. I am engineer but I work with theory and designs not the end product. I have never changed shocks before so naturally it is a bigger deal. I also dont believe in taking chances or guessing hence researching everything to the nth degree.