Front top mount centre nut - how to torque?

[Bossworld]

Sorry, may be a dumb question. I procured some second hand struts, I wanted to change the top mounts out as they'd done a fair few miles and the rubber was looking a bit worn.  I've taken the old ones off, fitted new ones, but now I'm stumped as to how to torque up the centre nut.

I've used my new impact wrench which does them up fine but cannot tell how far they're torqued.  When I try to use a torque wrench, it's causing the spring to turn and attempt to skip out of the bottom mounting point of the shock absorber.

Tried to Google it, people suggesting holding onto the shock piston with molegrips which I'm relucantant to do.

Have I missed something obvious like torquing it up when mounted on the car instead?

Thanks

[Joesson]

I tightened and torqued the centre bolts while the struts were on the car. The only problem I remember was the ridiculous price for Mr T 's nyloc nuts and wrote about it on here. I bought replacement nuts via the www.

PS a link to the above mentioned post, refers to the OE nut being loose.

https://www.mr2roc.org/forum/index.php?topic=49700.msg572798#msg572798

[Bossworld]

I tightened and torqued the centre bolts while the struts were on the car. The only problem I remember was the ridiculous price for Mr T 's nyloc nuts and wrote about it on here. I bought replacement nuts via the www.

PS a link to the above mentioned post, refers to the OE nut being loose.

https://www.mr2roc.org/forum/index.php?topic=49700.msg572798#msg572798

Thanks for the link mate.  These seemed to be OK, although I take the points raised in the thread about re-use.

I refitted to the chassis and despite my best attempts, was finding that turning with a torque wrench was just moving the spring.  The torque spec value wasn't particularly high (was about 50nm from memory) so I'm going on the basis that the windy gun will have got them tight enough when they were off the car.  The car is moving fine and the top mounts are moving as expected.  There is the same amount of thread visible as on the struts that came off.

[Joesson]

@Bossworld
Referring to my old post I mentioned that while removing the shocks I found that on one side the flats on the piston were not engaged with the slots on the top plate. If that is the case when reinstalling it would not be possible to correctly tighten the top nut in situ.

[Bossworld]

@Bossworld
Referring to my old post I mentioned that while removing the shocks I found that on one side the flats on the piston were not engaged with the slots on the top plate. If that is the case when reinstalling it would not be possible to correctly tighten the top nut in situ.

Cheers - Both of mine are on the flats, was a bit of a chew on during assembly and I saw that one side's top plate flats were slightly mangled. I did disassemble/reassemble that side twice to check the top plate's engagement and examined the shocks from upside down before refitting to the car.

I'm possibly not describing the issue I encountered properly - probably because I don't understand how the piston rotates in relation to the spring. When I say the spring moved, obviously it stays in place at the bottom but it felt at the top as if it was being flexed.

I've got an impact wrench so was able to tighten with no real drama, just in an ideal world I'd like to know what value I torqued to.

Interestingly Toyota's guidance is to hold the top plate in place with a screwdriver, while the spring is compressed, and tighten that way.

[Joesson]

Now you mention it I remember, from some written instruction, reference to use of a screwdriver usage for a non screwing operation. But I think that was for partial tightening, likely to engage the flats in the slot and then torque in situ.

That gives me a thought that I will post in a relevant section.

[gazza1286]

Tightening the top nut on the car is not really the best option. (this wasn't a problem with the Mk2)
An alternative method (I have found) is using a workmate. The jaws open just wide enough to wedge the lower part of the bearing assembly to prevent rotation. Also with the strut off the car you can see with certainty that the piston flats are fully engaged.