yungupgrade Posted December 20, 2022 Share Posted December 20, 2022 The 3 13 mm 12 point bolts holding the wheel bearing to the knuckle are stripped and I'm not sure what to do to get them off. I used my impact wrench with the 13 mm socket but now it only spins when trying to unbolt them. I can't hammer the 12 mm into the bolt head as its just slightly too small. I know people who weld old bolt heads onto these things to get them off but I unfortunately do not have access to a welder. Is there any other tricks I can try to get them off before I have to take my truck to a mechanic? I'm going to try using map gas tomorrow as well. Link to comment Share on other sites More sharing options...
ghetdjc320 Posted December 21, 2022 Share Posted December 21, 2022 Try using a bolt extractor or use the next step down on a standard socket instead of metric and hammer it on. Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted December 21, 2022 Share Posted December 21, 2022 You need to use a 1/2 inch 12 point socket. Link to comment Share on other sites More sharing options...
Airborne Janitor Posted December 21, 2022 Share Posted December 21, 2022 If you have access to oxy fuel heat up the knuckle around the bolts super hot. If you can't get any bite on the bolts with a big pair of vice grips, try grinding 2 flat spots on the bolt head opposite sides of each other so you can get an open end wrench on there. Highly recommend heat before any other destructive methods. Link to comment Share on other sites More sharing options...
MiNi Beast Posted December 21, 2022 Share Posted December 21, 2022 Been here before. I used a grinder and cut the heads off and hammered out the bearing and install new bearing and bolt and antiseized both. Link to comment Share on other sites More sharing options...
GrandBoost98 Posted December 21, 2022 Share Posted December 21, 2022 Heat is always helpful. some good vice grips or bolt extractor set could do it. Mostly recently, I had a caliper bracket bolt strip out on me. Nothing was working and then I had a thought to try a pipe wrench. Figured if it could grab and turn a pipe, why not a rounded off bolt? A little bit of heat and the pipe wrench turned it out no problem Link to comment Share on other sites More sharing options...
gogmorgo Posted December 28, 2022 Share Posted December 28, 2022 You might get lucky with a half inch socket, but they’re not a ton smaller than the 13mm. It’s critical to have the socket seated all the way with no angle. I’ve also cut the heads off the bolts in the past, as well as welding nuts on. Before you’re at the point of stripping the head out, getting heat onto it will definitely help. Heat the bolt or the hub where it threads in, not the knuckle. You have access to the back of the threads for heat, also penetrating oil. But both those options require you having something that will grip the head of the bolt to turn it. In terms of professional level tools, an induction heater is a huge help in this situation. They’re $$$$, but I use mine far more often than I do a torch. It’s just so much cleaner, more precise, you don’t have to worry about heating things you don’t want to, or setting things on fire… but again it is $$$$. Slide it over the bolt head, get it hot enough things start smoking (no real need to get it glowing hot unless you’ve tried a few times with no success), then clamp the bolt head with some vice grips and spin it loose while it’s still hot. From experience, hot metal looks the same as cold metal, so let it cool down before touching. My experience with extraction sockets is they often will do more damage than good, especially the spiral fluted kind. They do sometimes work, but if they bite but don't turn the fastener because it’s seized, they’ll turn your slightly stripped bolt head into a smooth, shiny cone. I’ve also had bad luck with lesser quality ones not really wanting to grab and losing their cutting/biting edge. Link to comment Share on other sites More sharing options...
OldSch88L Posted January 1, 2023 Share Posted January 1, 2023 Aww man, I hate those bolts!!! I got mine out by pretty much using all the tips mentioned here, but of course, a LOT of heat and PB Blaster helps a lot. I got some new ones with Hex heads so I won't have to fight them as much in the future! Link to comment Share on other sites More sharing options...
yungupgrade Posted January 2, 2023 Author Share Posted January 2, 2023 Update: 1/2 bolt extractor plus some mapp gas and PB blaster did the trick! No idea why those bolts were 12-point to begin with Link to comment Share on other sites More sharing options...
gogmorgo Posted January 2, 2023 Share Posted January 2, 2023 Glad to hear you got it out. 12-point bolt heads offer better grip in smaller sizes compared to 6-point, meaning they're a better choice for tight places or high-torque applications. I've honestly found that 12-point bolts are more resistant to stripping out than 6-point bolts, probably because you have better grip on the bolt head. We had one for the starter on a Maxxforce engine in an International that we didn't initially think we'd be able to get power tools onto, but we didn't have a ton of clearance for hand tools either. I'm a bigger guy and can lift 200+lbs, but it was every ounce of strength in my body, with feet braced against the front tire, pulling on the end of a 3-foot breaker bar just to budge the bolt. The thing seemed to fight me harder once I got the bolt started. I got it unscrewed maybe two full turns before it stopped dead, and there wasn't anything we could do to move it in either direction. I spent two hours on my Friday afternoon, my boss spent the entirety of the next day. Between us we broke every single 5/8" 12-point socket in the shop. Absolutely nothing worked, heat, penetrating oil, the thing just would not move. Can't believe we didn't strip it out. This truck puts the salt on the roads, so it's rusted to $#!&, it's pretty typical to strip out the 6-point bolts on it. Keep in mind the sockets crack because they're expanding from the force we put on them, so when they fail they spin on the fastener. Again, hard to believe we didn't strip it. Eventually I got it after realizing I could get enough stuff out of the way to sneak a few feet of extension down the frame to get a 3/4" impact wrench on it. I welded up one of the cracked sockets, then slipped a piece of tubing over it to reinforce it, and cycled the bolt red hot about five times before hitting it with the impact, and it barely creeped out. Felt like I sat on it for a solid ten minutes before it was loose but once it started to turn even just a little I didn't want to let off. For clearance reasons I had to adapt down to a 1/2" extension for the last foot, and I'm surprised I didn't break anything with the impact... the gun's rated for 1600lb-ft and it was pretty new. Link to comment Share on other sites More sharing options...
yungupgrade Posted January 2, 2023 Author Share Posted January 2, 2023 12 minutes ago, gogmorgo said: Glad to hear you got it out. 12-point bolt heads offer better grip in smaller sizes compared to 6-point, meaning they're a better choice for tight places or high-torque applications. I've honestly found that 12-point bolts are more resistant to stripping out than 6-point bolts, probably because you have better grip on the bolt head. We had one for the starter on a Maxxforce engine in an International that we didn't initially think we'd be able to get power tools onto, but we didn't have a ton of clearance for hand tools either. I'm a bigger guy and can lift 200+lbs, but it was every ounce of strength in my body, with feet braced against the front tire, pulling on the end of a 3-foot breaker bar just to budge the bolt. The thing seemed to fight me harder once I got the bolt started. I got it unscrewed maybe two full turns before it stopped dead, and there wasn't anything we could do to move it in either direction. I spent two hours on my Friday afternoon, my boss spent the entirety of the next day. Between us we broke every single 5/8" 12-point socket in the shop. Absolutely nothing worked, heat, penetrating oil, the thing just would not move. Can't believe we didn't strip it out. This truck puts the salt on the roads, so it's rusted to $#!&, it's pretty typical to strip out the 6-point bolts on it. Keep in mind the sockets crack because they're expanding from the force we put on them, so when they fail they spin on the fastener. Again, hard to believe we didn't strip it. Eventually I got it after realizing I could get enough stuff out of the way to sneak a few feet of extension down the frame to get a 3/4" impact wrench on it. I welded up one of the cracked sockets, then slipped a piece of tubing over it to reinforce it, and cycled the bolt red hot about five times before hitting it with the impact, and it barely creeped out. Felt like I sat on it for a solid ten minutes before it was loose but once it started to turn even just a little I didn't want to let off. For clearance reasons I had to adapt down to a 1/2" extension for the last foot, and I'm surprised I didn't break anything with the impact... the gun's rated for 1600lb-ft and it was pretty new. Broke my 1/4 swivel trying to get the last bolt out with my impact. To be fair it was a chrome socket, but I guess you have to learn the hard way sometimes. I can't imagine trying to work on a salt truck Link to comment Share on other sites More sharing options...
gogmorgo Posted January 2, 2023 Share Posted January 2, 2023 Just now, yungupgrade said: I can't imagine trying to work on a salt truck All I'm going to say is Link to comment Share on other sites More sharing options...
Pete M Posted January 2, 2023 Share Posted January 2, 2023 2 minutes ago, gogmorgo said: All I'm going to say is truth. Link to comment Share on other sites More sharing options...
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