Ball joint-to-knuckle bolt size

['88 All-Trac]

Does anyone happen to know the diameter/thread pitch of the ball joint-to-knuckle bolts? My steering knuckle was slightly damaged when my ball joint failed and I don't have the time or money to rebuild a new knuckle... I just need to helicoil or maybe just tap the bolt holes and reinstall the knuckle...

[96paseo]

Originally Posted by '88 All-Trac

Does anyone happen to know the diameter/thread pitch of the ball joint-to-knuckle bolts? My steering knuckle was slightly damaged when my ball joint failed and I don't have the time or money to rebuild a new knuckle... I just need to helicoil or maybe just tap the bolt holes and reinstall the knuckle...

IIRC, its M12x1.5 Easy way to check is take the other bolt thats presumably good to advance auto. They have a sizing board that you can thread the bolt into to confirm its size. I had this happen to the 89 I had where the threads stripped out of the knuckle upon installing a new ball joint. I purchased a Grade 8 1/2"x2" standard thread bolt. You can thread that bolt directly into the knuckle since the 1/2 inch is slightly larger than the M12 and it won't trash the threads on the new bolt. You will have to file out the inside of the ball joint a little to get it to fit nicely. It will grab inside the knuckle pretty well but to be safe here's part two. Buy a nut, flat washer and lock washer to match and lock the bolt onto the knuckle. There will be just enough of the bolt sticking out the bottom to add the nut and washers. Double check the size and measure before you go shopping. Its been over a year since I did this. I got the hardware from Home Depot for about $5. Good luck.

[Doctor J]

It is M12x1.25
Drill it oversize and use "class 12" metric M12 standard pitch bolt with flanged nut of the equal strength on the other side. Torque to 90 foot-pounds

[white90dx]

Originally Posted by Doctor J

It is M12x1.25
Drill it oversize and use "class 12" metric M12 standard pitch bolt with flanged nut of the equal strength on the other side. Torque to 90 foot-pounds

I'm gonna have to do this on the right front knuckle on my Alltrac.

-Charlie

['88 All-Trac]

M12 seems awfully small... But I'll take your word for it. I spent all day trying to find a helicoil and couldn't, as sizing charts all placed it between 16 and 18mm... Leading me to believe it was a 17mm bolt, though when I tried a nut-board to find the size it came out to a 16mm thread size.

I'm not sure if the bolt was torn out or simply backed out- I did tighten it a second time at 300miles after the work was completed, but you never can be sure with the temperature fluctuations we get here...