Suspension Torque Specs...

[PUR157]

Finally got off me bum to install those Teins I acquired a long time ago

Since I was installing it myself and winging it, when it came to the lower suspension strut bolt I thought I should do it up tight enough so that the suspension arm is free to swing since it will do so as the strut goes through the bump and rebound cycle

Afterwards I stumbled across the torque specs on miata.net
They say the suspension lower bolt is supposed to be done up to 100odd Nm (for those without a torque wrench that's pretty much "as tight as you can" right?)

So that would effectively "fix" the suspension strut?
So is the lower suspension bush supposed to provide some resistance as well?

I know I should follow the factory specs so I'll dive back under the car soon
but I'm just seeking some rationale

[Juffa]

Dug out the above two diagrams for the front and rear suspension. As I understand it the outer ends of the suspension arms travel in an arc. The distance of the arc travel is tightly controlled by the suspension dampers (aka shock absorbers). The pivot points are the inner subframe mounting points with bushes. In general the damper does not 'swing' as such, it extends, or compresses as the suspension follows the road surface and therefore the lower damper bolt does not have a need for any more movement than the bushes provide.

Of course I could be totally wrong and am willing to learn from those with a better understanding.
J

[philz]

Tight as hard as you can by hand and I've had no problems.. Obviously if the bolt is small like endlinks and strut top bolt, then use caution and common sense

[PUR157]

Thanks for that Juffa, sounds reasonable enough

I do feel the rear behaving a little differently over sharp speed bumps though... this might be the problem

Philz, to make that crystal clear... is that hand tight with a socket? or literally hand tight with some Kung Fu trained fingers of steel like you would do with the oil filter?

Problem is... common sense isn't common...
and I'm the type of person that worries about everything... (a head littered with white hair at the ripe old age of 22...)

And what about pre-load of the bush then?
Would it matter if I tightened the bolt up while it's raised as opposed to doing it at ride height?

Gosh I really need a service manual...

[Juffa]

And what about pre-load of the bush then?
Would it matter if I tightened the bolt up while it's raised as opposed to doing it at ride height?

Gosh I really need a service manual...

You should tighten the suspension with the weight of the car on the suspension. I usually have the car on stands for this kind of job. I then raise the lower suspension arm on each corner until that corner is supported by the suspension. I then tighten the nuts/bolts to the correct torque settings.

J

[philz]

hand tight with socket, breaker bar, whatever.

I don't have guns of steel unfortunately, but as long as it's not loose you will be okay.

Some may disagree with me, and say use a torque wrench, but I'm not that anal.

tighten enough where you say "that's all I can do".

Not grab a 4ft cheater bar, stand up for extra leverage, or jump on the bar.

But in saying this, if you aren't confident, just buy a torque wrench.



With preloading, you can do it two ways, jack the car up on stands get the floor jack under the lower control arm, or wheel, pump it up until it looks like ride height, then tighten.

Or drive it on ramps and tighten.

You can tighten without preload, but your bushings will ƒü¢k up alot quicker.
It doesn't have to be exact ride height, but enough to load the bushings.

[de Bounce]

If you have access to a Torque Wrench
I found these on another site and are for an NB.
All are in Ft/Lb's
Swaybar bushing bolts, front - 13-20
Swaybar bushing bolts, rear - 14-21
Swaybar end link bolts, both ends - 27-40
Upper shock mount plate bolts - 22-27
Upper shock nuts - 23-34
Lower shock bolt - 54-69
Lower control arm bolt, front - 54-69
Spindle (vertical) bolt - 54-69
Camber adjustment bolts, (D or H-style) front - 69-83
Camber adjustment bolts, (D or H-style) rear - 54-70
Wheel Nuts - 66-86

[PUR157]

Great!

thanks for all that guys, now I can dive under the car with confidence...

thanks de bounce, but mine is a NA... but should be roughly similar really

(here's the link if anyone was interested...! kept forgetting to post it up...)