shock absorber screws
 

on the 1998 xj the two rear shock upper bolt heads twisted off on one side. will probably be same on other side, no way to get them out.

is there enough meat to drill out and enlarge the thread to m10 (from m8) or are these just some thin walled inserts? in that case the only other option i see is to try welding on studs.

thoughts?

Use an air hammer to break off the captive nuts. Then you can either use new bolts and nuts, accessing the head of the bolt on the inside by slipping a wrench through a hole in the crossmember, or use something like this:

Welcome to the club, lol.

do this.
I did this exactly.

I pounded out all 4 of mine last week using a hammer and 10” chisel. No picnic. A multi day event in fact.Then just scotch tape new 5/16 bolts to a wrench and drop them down.

i dont have an air chisel and just a small compressor for tires. how hard is it to get rid of the nuts with a hammer?

edit: upon inspection the portruding screws seem to be contacting the upper sheet metal. so i dont know how how the nuts would react to pounding. but others have done it, right? is there any sign of the screws in the trunk (before i rip out the carpeting)?

No, you can't get àt them from the inside. If you hit them hard enough with a punch and hammer they will break away. Hammering uphill while laying on your back builds character.

Yep what he said. I also heated with a propane torch. Hot as you can get them, gas tank out. What helped also was raising it high enough to get a good swing. You really need some blows on it. On the passenger side I also had to cut the back exhaust hanger and pull it out of the way with some wire. I’m not gonna lie it’s a true PITA but if you have self discipline and patience and perseverance they come out. After you get the first one it’s a confidence builder. You’ll be a better person in the end.

Air chisel is 17 bucks at Harbor Freight. Chisel kit 7 bucks.

An air compressor is an essential tool.

Air chisel trick takes seconds.

How much is your time and staying free of aggravation worth?

Flintstone mechanic.

You’re no fun.

thank you so much everbody.

it was quite an easy job in the end. those nuts are only weakly tacked somehow, two good spot welds would have survived the procedure.

i used a 900w construction-hammer grinding the tip of the chisel a bit flat. 3 nuts came out after about 20 seconds each, the fourth screw twisted off convex and portruded a bit. i had to grind it concave with my chinese dremmel-on-steroids and a carbide bit. on top of that the air hammer gave up the ghost, so i finisched it off with a hammer. actually i guess this can be done with a hammer only. the screws are very short, i was wrong before.

i fished out 2 of the nuts, 2 "disappeared".

so i glued in four ss m10 studs into flange nuts and and milled 7mm flats on the ends. had to grind one slot in the whishbone a bit longer. now the instal is super easy.

first i tried to handle the nuts with a magnet but used a wrench in the end. one of the nuts is easy and can be inserted by taping it to a box wrench (angle is just right). the other one needs an open wrench (cant lift the box wrench) and its a bit finicky to get the nut at the proper angle but can be done. if i had to do this repeatedly i would bend a wrench to suit (17mm).

My floor was rotted anyway so it was easy to get to them from the top. After replacing the floor, I planned on drilling 1 inch access holes and installing rubber plugs, but then I discovered the flag nuts in the Amazon link. So quick and easy.