stripped caliper bolt head!!

[a bum with money]

I'm replacing all ball joints on my 88 MJ, 2wd 4.0l, auto, big ton. I've tried a series of ideas trying to remove a stripped caliper bolt head, no luck. it's the LH upper 6 point bolt head.

 

one question is I was going to replace all 4 caliper bolts with a flange hex head bolts unless someone can suggest a different solution. from my understanding these bolt types were changed in 1990? 

 

right now I'm unable to remove the rotor hub assembly. was going to disconnect the brake line at the caliper and tie rod and remove the entire assembly as a whole and take it to a machine shop to have the bolt removed.

 

another idea was once I've removed the knuckle assembly, could one grind off the caliper bolt head and then remove the caliper from the knuckle?

 

I'm sure this has happened before and would like some direction as to a solution.

 

appreciate your opinions

thanks Bryce

[89 MJ]

You can try welding a nut to the bolt head. Also try pounding a smaller size socket onto the bolt head. Is there room to drill the bolt out or cut the head of the bolt off?

[Comanche SS]

They are tough ones for sure, weld a nut to it. 

I have Spares if you want to replace with OEM style instead of Hex head.

[a bum with money]

1 hour ago, 89 MJ said:

You can try welding a nut to the bolt head. Also try pounding a smaller size socket onto the bolt head. Is there room to drill the bolt out or cut the head of the bolt off?

 

 

I like that. I do have a welder, but in order to do this I still have to remove the knuckle assembly of the front axle. which I'm to do w/o a gas torch set-up. but I do have an 8# sledge and a good size pickle fork.

 

thanks 

 

[a bum with money]

1 hour ago, Comanche SS said:

They are tough ones for sure, weld a nut to it. 

I have Spares if you want to replace with OEM style instead of Hex head.

or

well is there any disadvantage using the hex head bolts over the OEM? they are 10.9 grade

 

just for the hell of it shoot me a price with approx shipping   I'm @ 97211 area code

[a bum with money]

2 hours ago, 89 MJ said:

You can try welding a nut to the bolt head. Also try pounding a smaller size socket onto the bolt head. Is there room to drill the bolt out or cut the head of the bolt off?

 

 

yes I did and broke two sockets trying. but I like the welding idea

[pizzaman09]

I've been successful with the welding technique on similar bolts.  It might take a couple welding applications and a few nuts to pull off.  The heat from welding helps the nut break free.  I recommend getting as much heat into the bolt head as possible if you are trying this.

[a bum with money]

5 minutes ago, pizzaman09 said:

I've been successful with the welding technique on similar bolts.  It might take a couple welding applications and a few nuts to pull off.  The heat from welding helps the nut break free.  I recommend getting as much heat into the bolt head as possible if you are trying this.

 

 

I agree

[a bum with money]

success! I was able to weld a 5/8" thread nut on the caliper nut and it was a cinch to get it out and proceed with the ball joint replacement.

 

thanks again to the members for their input. greatly appreciated!

 

Bryce

[89 MJ]

[pizzaman09]

Woohoo! 

[AnotherOldJeepGuy]

Congrats on the successful extraction!

 

Just FYI, I recently purchased new ones from rock auto that fit perfectly and did not cost much.

https://www.rockauto.com/en/moreinfo.php?pk=1133353&cc=1181720&pt=10281&jsn=6

 

Lubricating the ones you put in should help this from happening in the future.

https://youtu.be/Yj6f8crrwZ4

 

[a bum with money]

On 4/5/2025 at 10:22 AM, AnotherOldJeepGuy said:

Congrats on the successful extraction!

 

Just FYI, I recently purchased new ones from rock auto that fit perfectly and did not cost much.

https://www.rockauto.com/en/moreinfo.php?pk=1133353&cc=1181720&pt=10281&jsn=6

 

Lubricating the ones you put in should help this from happening in the future.

https://youtu.be/Yj6f8crrwZ4

 

 

I saw those. but mine are the caliper bolts with the 6 point star head that held the caliper to the knuckle.