2005 - Sterring Knuckle Caliper Bracket Bolt Holes are threaded - Heli-Coil repair?

There are no M9x1.25 bolts on any Toyota vehicle.


If the bolt has a 14mm hex head, the bolt is M10x1.25. Toyota uses J.I.S. or Japan Industrial System fasteners.

 

Heli-Coils and Time-Serts work well. I'm more familiar with Heli-Coils, Time-Serts might be newer (but regarded as sturdier). Nothing I've repaired with a Heli-Coil gave me a problem.

On the other hand, the caliper mounting to the knuckle handles substantial forces, and there's not a whole lot of meat around those holes, and some of it goes away when you bore oversize to put the insert in, and the knuckle only sets you back a shade over $200 even if you get one in a red and white Toyota box.

 

You'll be just fine with the HeliCoil. The weakest link in a fastener is always the bolt, which is under tension when tightened,

Failure always occurs with the shearing, by either ductile or brittle fracture of the bolt, not the threaded hole or the nut. Ductile fracture occurs with low tensile bolts, while brittle fracture occurs with hardened bolts.

Failure of the internal threads only occur from corrosion ir mechanical upset, such as cross threading.

A larger diameter threaded hole is much stronger than the original.

HeliCoils are approved for mission critical fasteners in aircraft. They are often preinstalled in soft and weaker frangible materials like plastics and aluminum to achieve greater impact resistance in harsh environments.

You'd be just fine, if you use a HeliCoil.

 

Is it possible to use a longer bolt and put a nut on the other side?

 

Both 14 and 17 mm hex heads are used on Toyota M10x1.25 bolts. To verify which you need, just measure the width in millimetres across the tip of the bolt. Toyota only uses 1.25 thread pitch bolts.

 

17mm is the size of wrench you would use on the bolt, but the diameter of the bolt itself is not 17mm.

 

If you don't have a metric ruler just fit a 10 mm open end wrench over the tip to check the width,

 

Correct

 

It might be an M12 bolt, so 12mm diameter. And if you do decide to get a longer bolt and use a nut make sure the new bolt is the same grade as the old one so it doesn't break.

 

It's a special necked down collar bolt. If you a longer want one, it would have to be custom made.

 

This is true about the specialty bolt...using a different type could have negative effects on braking. I think they are called shoulder bolts with a flange, or flange bolts with a shoulder. Maybe just go to a junkyard and buy a used spindle part for a few bucks.

 

Ummmm. You DO realize that according to the service manual, the bolts that hold the front brake caliper mounting brackets go THROUGH holes in the steering knuckle and into threads in the bracket itself? (torqued to 81 lbs-ft)

That said, I wouldn't be surprised if you had a bunch of corrosion built up IN the steering knuckle holes (around the bolt shanks).

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Here's another pic.

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Why you don’t consider to buy a used part from junk yard? It’s only like 50$
Don’t play or experiment with a brakes.