cross threaded bolt

[60apache4]

I'll be darned but I cross threaded a grade 8 fine thread bolt on my truck yesterday and need to know how to fix it. I may be able to re-thread with a tap but there are clearance problems, or will i need to heli-coil it. Thanks for your help...Tom.

[Jeepster376]

It depends. The threads are damaged now. if you re-tap it you can clear the way to proerly thread the bolt in, but the threads are still damaged and weaker than original. If this bolt neads to be torqued the threads could strip out, and probably should be helicoiled. If it's a shear loaded bolt that doesn't need to be torqued, then you may be OK without the coil.

[68LSS1]

Sonce it's a grade 8 bolt I'll assume that it's use is more for clamping (as opposed to say a grade 5 for shear strength). I would run a thread saver in it and then torque the bolt. If the threads pull then heli coil it. If it holds the torque it will be fine. A thread saver is not the same thing as a tap by the way. There are meant for cleaning and restoring threads not cutting them like a tap. Similar to a thread file but for holes.

[Stepsides 4Ever]

I learned a long time ago to always start a bolt with my fingers...if it binds, find out why and fix it, don't just grab the impact.

Where is the bolt located, and what is the type of metal that is damaged? There's a thread repair item called a kee -something that is a hardened insert with internal and external threads. You thread it like a helicoil, screw the insert in, then there are 4 little keys on the OD of the insert that you drive in with a hammer to keep it from turning. I'm sure there are others, but a lot of it depends on what you are trying to fix and the type of material that needs repair.

[Jeepster376]

I think that's a Keen-sert your refferring to

[60apache4]

Thanks for the help guys; I'll work on getting it fixed this weekend. The bolt attaches the backing plate to the flange on the end of the axle tube. 3 of the 4 bolts are fine. I did thread it by hand to start but must not have been far enough because when I put the air wrench on it the impact must have caused it to fall out and by then it was too late...

[toddtheodd]

Maybe it's just me, but can't you replace the bolt. I bought a sh**load of different sized grade 8 bolts and whenever I'm working on something I just replace the bolts and nuts with new ones. Lowes has tons of different sizes and thread patterns.

[Jeepster376]

Originally Posted by toddtheodd

can't you replace the bolt.

The bolt isn't the problem, it's the axle flange that was damaged.

[muddbugg72]

could you tap the flange to the next size bolt and just drill out your backing plate to fit new bolt size