Just got my tanabe DF210 springs after a couple months of waiting and I知 having trouble with the front struts. Did the rear ones with ease. Everything else comes off the front fine except the upper strut nuts off either strut and it just free spins. Blasted it with WD40, then let it sit for an hour, used the 6mm hex wrench and 17mm wrench but it won稚 budge. Debated on just returning them but now I知 having trouble re-installing the stock rear springs and getting them to fit. Tried compressing them but wasn稚 able to remove the compressor tool after I had them seated. Now I知 driving a squatted fit just lowered in the rear so any help would be appreciated lol.

 

You sure the 6mm hex wrench is the right size? I'm thinking of doing my own and videos I watched show 7mm hex wrench

 

What you can try is to "double nut" above it.

What you'll need are two nuts that fit on the remaining thread at the same time. I accomplished this by slicing/trimming down a pair until they were thin enough. Once you get them both on, tighten them against each other until neither moves. Then use them as anchor with another wrench, while you try to break the original nut you wanted to remove.

Another way, if you have a new mounting hardware nut and was replacing the strut too... slice the whole top strut off. I ended up doing that to one side when I needed to replace the strut and spring. After that, I gave it to a mechanic to do the other side, figuring he'd have better tools or something... wrong, he sliced off the other side too.

It'll actually be two cuts. The main is a vertical cut down the nut to split it in half to either side of the threads. The other cut is a horizontal cut before that, just so you don't have too much material to cut through during the vertical cut.

If attempting the "original" way of Allen wrench... you'll need to make sure the Allen wrench is very strong and can be "anchored" in some way... either against some other part of the car or with a "breaker bar." I put a pipe on an Allen wrench to give me leverage, but only ended up twisting the Allen wrench itself.

 

I don't invest time messing with those top nuts anymore. Remove the assembly, compress the spring. the top nut holds the spring on and the spring holds the top nut on (as well as a good amount of corrosion due to placement on vehicle catching lots of water n dirt that goes behind the hood in a freaking cup)
After the spring is compressed I cut right through under the top nut and into its washer and the rubber mount a little bit. An $80 makita (or any brand) 4 1/2" angle grinder with a new blade just makes the distance with the guard on.

Angle grinders freak me out, so i dont try n get technical with them. Could use a reciprocating saw, but the long blade would likely hit the driveway if i just put my foot on top the assembly like normal.
​​​​​​Keeps the face farther away from the flying bits v. holding with hands.

EDIT: Oh you may be able to take the car to an exhaust shop and have a welder affix a nut to the top strut stud if the allen rounds out.. kinda lame, but an option. id likely just get new struts n mounts..
has anyone here anti-seized the top nut for struts to prevent this?

 

Well, the reason I ordered Koni Orange struts was because I thought my front struts failed... but it turned out that the top nut had managed to work itself loose (almost completely off the strut).

Between that and the upper grommet failing, I have enough fears of my struts falling out.

So, yeah... I'm not gonna put anti-seize there.

But that said, can't really win... either it's stuck or it's coming loose.