Can't remove strut tower nut

[JPMo]

I don't know why I try DIY since it seems every little thing I do becomes a difficult ordeal lol /rant.

Anyways, forgive my lack of technical knowledge and lingo but I managed to get an OEM M3 strut bar. I tried to install it, but one of the nuts that need to be removed to place the strut bar mount keeps spinning with the attachment bolt as if unattached to the strut.

I'm attaching a picture. What do I do to remove it given the issue I'm facing.
https://uploads.tapatalk-cdn.com/20170324/94fe904366a4911b2063869d9dfd8c39.jpg

Thanks

[TheFinanceGuy]

That stinks. Sounds like the stud has become un-attached from the strut hat. By the way it sits lower, I'm guessing that is correct.

The repair - includes a new strut hat, which involves compressing the springs... I hope I'm wrong, and someone else has a better idea.

[ELCID86]

I agree. Probably need to drill out the offensive bolt. I don't think there is any way you can get to it and grab it from below. Would an air wrench have enough torque to out spin the bolt? May be worth a try.

[JPMo]

Would an air wrench have enough torque to out spin the bolt? May be worth a try.

Thanks for the input, I would be willing to try but don't have an air wrench. I was hoping I could stick a wrench underneath to hold the bolt but theres like a few mm gap between the nut and strut tower so thats not happening.

Edit: Is it safe to drive around with a loose stud? The nut is definitely not completely tightened so theres some play as I mentioned. I've already put 8000 miles on the car since I purchased it, so Im assuming its ok, but I don't really know when or how the bolt could have detached itself.

Its always something... :facepalm

[warrenbrown]

I've not had my E46 apart to that point, on E30 and E36 cars, that stud is part of the strut bearing. The studs are pressed into some sheet metal, the studs pave a serrated portion under a larger head. The serrations engage in the sheet metal and generally don't come out easily. Yours looks lower, leading me to believe it unthreaded several turns and then got pushed down. I suggest getting a wonder bar or claw hammer under the nut and gently apply some pressure upward on the nut while trying to unthread it. If you get it off, the stud is going to fall down. I doubt you can get a replacement bolt in there to replace the stud. You might be able to feel up in there from the underside. Alternately you could try tightening it in the same manner but soon you are going to be left to your imagination as to how to apply upward force while turning the nut. I don't know if those are locking nuts, if they are, you might be better off removing it and have someone hold it and replace the nut with a non-locking nut that will free spin with upward pressure. I'd guess you can drive the car till you get an appointment if you are not inclined to do it yourself, it is a lengthy job to replace the the strut bearing. Spring compressor is a must.
https://www.ecstuning.com/b-genuine-bmw-parts/upper-strut-mount-right/31332229166/?utm_source=bing&utm_medium=cpc&utm_campaign=Srch.US.ProductAds(BSC)&utm_term=1100910268440&utm_content=All%20Products
Good Luck
Warren

[ELCID86]

It may be worth buying (or borrowing) an air wrench--excuse to get another tool!

It may be moderately safe since the other two are in place, but it was designed to have 3 for a reason... be careful not to push down too much on the sheet metal as it may bend in (they are know to mushroom out). When you order the bearings, order the strut plates to keep it from mushrooming in the future.

[BMWCurves]

It's not ideal that it's loose, but my guess is it should be okay for now. The bolt isn't going anywhere since the strut tower nut is on there holding it in place. Unless the strut mount rotates with enough to shear the bolt, I doubt it'll break either. Below is an image of the strut mount. For whatever reason the bolt is loose. If you remove the wheel you might be able get at it, but it'll probably be tight. You'd just need a good set of vicegrips to hold the round bolt in place. Below is a pic of the strut mount, and another pic of my assembled front strut and as you can see there is some space to get at the problematic bolt

http://i.imgur.com/RFqg9hZ.png

http://i.imgur.com/PPkQjij.jpg

[Cadeez]

If it were me, I'd spray some PB Blaster (or any penetrating fluid) onto the threads, let it sit for a bit. Then grab as much of the threads as you can with vise grips and see if you can TIGHTEN the nut, as much as you can. By doing this, the idea is to press the head back up into the mount, so the teeth lock in and grab again. IF you're able to do that, once it's as tight as you can get it, then loosen it up and see if the stud stays in place and you're able to get it out. The vise grips may mess up the top threads a bit, but at this point it's trash anyhow, no loss either way.

I've actually done this with a shock mount I had out of the car while replacing some suspension components. The stud came out, so I hammered it in as much as I could, then put the nut on and squeezed her back into the mount. It worked great.

[BCS_ZHP]

Okay, my shade tree mechanic coming out. Use a hacksaw and cut a groove into the top of that stud as deep as you can. Then insert a screwdriver in the groove you just cut. Hold the stud steady/still and use an open ended wrench (think it's 13mm) to tighten the nut. Tightening of the nut will pull the stud back up into the strut top hat and will resecure the stud to the top hat. That should work until you do a suspension refresh some day.

And a don't worry note - the front strut & spring assembly put positive force upward on that shock tower. As long as your front end isn't completely off the ground, there will always be positive/upward force. Even when you remove those 3 nuts during a suspension refresh, and having the car off the ground, you still have to compress the spring to get those studs out of the holes.

[WOLFN8TR]

Okay, my shade tree mechanic coming out. Use a hacksaw and cut a groove into the top of that stud as deep as you can. Then insert a screwdriver in the groove you just cut. Hold the stud steady/still and use an open ended wrench (think it's 13mm) to tighten the nut. Tightening of the nut will pull the stud back up into the strut top hat and will resecure the stud to the top hat. That should work until you do a suspension refresh some day.

And a don't worry note - the front strut & spring assembly put positive force upward on that shock tower. As long as your front end isn't completely off the ground, there will always be positive/upward force. Even when you remove those 3 nuts during a suspension refresh, and having the car off the ground, you still have to compress the spring to get those studs out of the holes.

That's actually a good idea! Or try using a screwdriver and wedge it under the stud right at the flat head in the fender well side and see if you can turn the nut off. The stud might come out but you can always put it back in afterwards.

Don't worry about driving around without one bolt, I did on my ZHP for over a year with NO issues.

[JPMo]

Thanks everyone for the advice, I think I may try the hacksaw route. It really stinks being in an away from home in an apartment haha no garage, no random tools from your basement, but tons of strange looks.

[BCS_ZHP]

Ran into my Indy mechanic when out at dinner tonight. Told him your dilemma and what I recommended, he said he'd do exactly the same thing, although he'd use a power/air-tool cutter vice a hacksaw because he has a shop and has those tools readily available. Give the hacksaw cut a shot and report back how you it worked out for you.