[TheHunterHofman]

Hi all,

Would anyone know if the bolts of the strut top mounts are one time use bolts, and what the appropiate torque value would be?

Here's a picture of the bolts (circled in red):

View post on imgur.com

Thank you and regards,

[x233]

One time.

[M Fifty]

..but... given the torque setting, this 'may' be due to them having an electroplated passivating layer that gets damaged in use. Any sign of rust on the threads may - therefore - be reason to change them.

[F87source]

Originally Posted by HunterHofman

Hi all,

Would anyone know if the bolts of the strut top mounts are one time use bolts, and what the appropiate torque value would be?

Here's a picture of the bolts (circled in red):

View post on imgur.com

Thank you and regards,

Torque specs are 30 nm + 90*.

Bolts are single use torque to yield so you must replace them if you ever remove them. The reason why is because they are stretch bolts, after you yield the bolt it will stretch it past the point of material elasticity and permanantly deform the bolt, if you reuse them they will not longer be able to apply the same clamping load that the engineers expect, and if you restretch them and they are also susceptible to breaking if you keep stretching them (this is the big reason why you need to replace them).

Originally Posted by M Fifty

..but... given the torque setting, this 'may' be due to them having an electroplated passivating layer that gets damaged in use. Any sign of rust on the threads may - therefore - be reason to change them.

No this is incorrect, the reason why is because the bolt is torque to yield. TTY bolts are single use for the reasons I listed above (integreity of the bolt is compromised after that first yield), and the same applies to aluminium bolts that are tty (for eg bed plate bolts) too and those bolts don't rust. So corrosion is not the reason why they're single use.

[F87source]

Originally Posted by HunterHofman

Hi all,

Would anyone know if the bolts of the strut top mounts are one time use bolts, and what the appropiate torque value would be?

Here's a picture of the bolts (circled in red):

View post on imgur.com

Thank you and regards,

Btw are you getting a strut tower brace?

[TheHunterHofman]

Originally Posted by F87source

Torque specs are 30 nm + 90*.

Bolts are single use torque to yield so you must replace them if you ever remove them. The reason why is because they are stretch bolts, after you yield the bolt it will stretch it past the point of material elasticity and permanantly deform the bolt, if you reuse them they will not longer be able to apply the same clamping load that the engineers expect, and if you restretch them and they are also susceptible to breaking if you keep stretching them (this is the big reason why you need to replace them).

No this is incorrect, the reason why is because the bolt is torque to yield. TTY bolts are single use for the reasons I listed above (integreity of the bolt is compromised after that first yield), and the same applies to aluminium bolts that are tty (for eg bed plate bolts) too and those bolts don't rust. So corrosion is not the reason why they're single use.

Got it, thank you. I'm willing to loosen these (and replace them) to potentially help the clicking noise of the suspension. I have also ordered the repair set in step IV of the following guide: https://f87.bimmerpost.com/forums/at...8;d=1637705967

[F87source]

Originally Posted by HunterHofman

Got it, thank you. I'm willing to loosen these (and replace them) to potentially help the clicking noise of the suspension. I have also ordered the repair set in step IV of the following guide: https://f87.bimmerpost.com/forums/at...4&d=1637705967

Ah so you have that clicking noise, thankfully that hasn't occured on my car yet so Im hoping it never does.

You probably should get a strut tower brace while you're at (I mean they're relatively cheap and a nice little mod) it so you don't have to replace the strut bolts again in the future if you do decide you want one.

[TheHunterHofman]

Originally Posted by F87source

Ah so you have that clicking noise, thankfully that hasn't occured on my car yet so Im hoping it never does.

You probably should get a strut tower brace while you're at (I mean they're relatively cheap and a nice little mod) it so you don't have to replace the strut bolts again in the future if you do decide you want one.

Do they add any actual noticable benefits? What would be a nice one?

[F87source]

Originally Posted by HunterHofman

Do they add any actual noticable benefits? What would be a nice one?

It does offer a bit more front end stiffness, I can see that when the car is jacked up on one side and I try to remove just the bar (on the braces with a removeable bar - which I recommend so when you do spark plugs you don't have to buy new strut tower bolts every time like you would on a one piece bar) it is really stiff and stuck in there because the towers have moved a bit and pressed the bar against the brackets. So it does do something, but I have not noticed it as much as some others say they do when driving the car. Some people report better steering feel but again I haven't noticed it.


Some good braces are like racing dynamics, weichers (they are in Germany so it would probably be cheaper for you), and so on so forth. There are alot of brands out there so I guess you have the luxury to pick.

[M Fifty]

Originally Posted by F87source

Torque specs are 30 nm + 90*.

No this is incorrect, the reason why is because the bolt is torque to yield. TTY bolts are single use for the reasons I listed above (integreity of the bolt is compromised after that first yield), and the same applies to aluminium bolts that are tty (for eg bed plate bolts) too and those bolts don't rust. So corrosion is not the reason why they're single use.

Well, I may be mis-remembering which ones were not much more than finger tight, vs. the torque to yield now that NewTIS is dead.