Cross-threaded strut tower studs

How did this happen? I'm literally on the last step of the spring install, car is on the ground, strut tower brace is loose, torque wrench set to 34 NM / 25 ft-lbs (not 34 ft-lbs). Driver's side nuts torque down fine, passenger side nuts gave way. They didn't even feel close to 25 ft-lbs.

These were brand new studs from the top mount in a Dinan ride comfort kit that I installed into their camber plates. No issues with the install. I used a nut to draw them in part way and then a punch to hammer them the rest of the way. Maybe drawing them in weakened the threads somehow? It didn't feel like I was cranking on them hard at all. It frustrates me that Dinan can't sell camber plates with these pre-installed. It's $5 in material and their parent company probably has 50 machines that could press them in.

Brand new nuts as well. BMW changed the design of the nuts so they're capped off instead of open, but they had plenty of height for the studs.

I can hear it clunking slightly from the right front on my test drive. I assume it's not safe to drive. I'll see if my indy shop is willing to deal with this. Otherwise I'll have to see if I can get a nut splitter in there with the strut tower brace in the way. Then I have to decide if I want to reuse the factory original studs, try to source a replacement, or buy a brand new top mount.

I'm scared to mess with the driver's side now too. I had planned to replace the struts sometime in the next year.

Only other thing I can think of is that after loosely tightening the bolts, I loosened them slightly to confirm the studs were maxed out with negative camber. I believe they're single-use nuts with loctite pre-installed? Maybe that was enough to mess up the threads.

Some aftermarket top mount studs are only 23NM. Been there, done that.

spammysammich wrote

Some aftermarket top mount studs are only 23NM. Been there, done that.

The Dinan ride quality kit looks like what appears to be a cut-down BMW top mount. I'll call them in the morning. Maybe they could send me some new studs or know the spec on them.

Something else was wrong. Two of the bolts hadn't even bottomed out yet. The strut tower brace was still loose.

Maybe I needed to double check that the cap nuts were able to make it all the way down. It's possible there's a little extra length on the studs when installed into the camber plate and I should've used a couple small washers or something. But if that were the case, I would've expected it to be very hard to turn.

Nope, you were right. From the instructions:



Damn it, Dinan!

tjames975 wrote

The Dinan ride quality kit looks like what appears to be a cut-down BMW top mount. I'll call them in the morning. Maybe they could send me some new studs or know the spec on them. Something else was wrong. Two of the bolts hadn't even bottomed out yet. The strut tower brace was still loose. Maybe I needed to double check that the cap nuts were able to make it all the way down. It's possible there's a little extra length on the studs when installed into the camber plate and I should've used a couple small washers or something. But if that were the case, I would've expected it to be very hard to turn.

Sorry this has happened to you. I recommend calling Dinan just as you mentioned and let them know what happened. It's possible they will give you a "good-will" adjustment on new parts. If nothing else it will alert them that the part(s) have an install issue. Once you decide on which way to go remedying the situation it's probably best to let your indy shop take it from here and save yourself any more headaches or frustration. Then it's on the indy shop. Let the indy shop know what has happened just in case there's some other trick to the install such as jacking up the wheel to engage the studs into the fender or similar.

KW plates are the same spec. Bummer.

From my Subaru experience i usually only give them about 14-15 lb ft to avoid snapping them. That was plenty for keeping camber plates in place, unless the manufacturer specifically stated otherwise. Same held true for my KW.

One down. I was able to manhandle it with some Vise-Grips.



The strut tower brace paid the price. Nothing a little spray paint can't fix. I'm still not sure what the failure point is. I'll mess with it the rest of the week. Dinan wasn't helpful.

I do have the camber plates from FCP Euro. I might want a fresh set of those since they've already had a stud in there once. It ought to be fine, but...

Right now I'm tempted to reuse the factory studs from the original top mounts. I want to figure out the thread pitch, then clean up the threads really well so the nuts bottom out smoothly. Then maybe throw a dab of blue Loctite on there to match whatever goop is in there from the factory (I think?) Or just go without that and listen for a clunk in the future. Or buy some nylon nuts and call it a day.

My KW studs bottomed out in those style nuts. Almost ruined the new studs I purchased. Check to make sure you aren’t doing the same.

spammysammich wrote

My KW studs bottomed out in those style nuts. Almost ruined the new studs I purchased. Check to make sure you aren’t doing the same.

I remembered I did check with calipers and I had a few millimeters leftover. They're also the only thing BMW sells for that part number now. I don't know where to get the other ones.

But I am considering reusing the factory nuts on that side to go with the studs. I just need to clean up the threads to get whatever gunk is on them.

Were you able to get new studs separately or do you mean as part of a new top mount?

I had to order all new studs from KW because I ran mine in too tight, snapped one and stretched the shit out of the rest and didn’t trust them. My clubsport camber plates came with their own open ended nuts that extend down into the strut tower like the black ones.

I manhandled the last two cap nuts. The third one was cross-threaded too, maybe because I drove around the block with the other two loose. That one I wasn't able to rock back and forth and break like the first two. I used a 13mm long socket and pushed the ratchet hard against the side of the nut, then slowly loosened it. The threads caught and I was able to remove it normally.

The studs are all loose in the camber plate now though. No more press fit. I'm going to call Dinan and take their offer of some free replacement parts. I want to get a new 21mm strut top nut as well. I plan to get the car back together later this week for a track event next week.

I cleaned up the stock cap nuts and studs with thread chasers. I'll put a dab of blue loctite on there. Before I do that, I'll run them down to make sure everything is 100% smooth.

My final theory is I damaged the studs slightly while hammering them in. (I had them against a couple 2x4s.) That was enough to mess it up such that the hardened factory blue loctite didn't thread on properly and cross-threaded it.

I have to do this again next year to replace the struts and shocks. I'll definitely use some heat to melt the blue loctite, then hope for the best. Even if it breaks, I know I can tackle it!

Car is back on the road. My plan worked perfectly to clear out the old loctite and add a dab prior to install. Very easy.

Thanks everyone for the help!