Nutz About Bolts Prius Maintenance Videos

The 12mm triple-square points are very slightly further out. Also, each point is 90 degrees (corner of a square) whereas with the 10 mm double hex the corners are 60 degrees (corner of hexagon). The latter just fits better, same shape as the head bolt pocket.

part2: just getting into it, the summary of the Toyota gasket kit is very helpful, with inset pics for each application. Never seen anyone else do this summary.

 

Here’s the 3rd video

 

Yeah, because of the different geometry, a 12 mm triple-square and a 10 mm double-hex are about the same size, and they both fit the head bolts. It's just that the Toyota head bolts are double-hex, so the double-hex bit fits them better.

 

Glad to know that, will try that next time and see if it feels differently or not.

nvm

 

Mendel drew this picture six years ago or so. Magenta for triple-square, cyan for double-hex:



Putting the triple-square driver in the double-hex bolt head kinda transfers torque only at the points of the square. The double-hex driver will have its faces flat against the bolt-head faces transferring torque.

 

thanks, yeah I can see how different it can be. So far, I don’t have issues with it. It’s like a 6 point socket and a 12 point socket, which one gives better bite. All works the same, just better torque when tightening it down.

 

Curious, did you reuse the head bolts? Likely all good.

 

Yes, I reused the head bolts, I asked the parts guy if they sell head bolts and he said they do, but they rarely replace head bolts. So I just reuse it. It was expensive for 1, I believe it was 8$ or 18$ for one I think.

 

Did you measure them? They are stretch bolts, and they stretch.
I bought new ones from Toyota, I believe it was less than $50.

 

$50 is relatively cheap, comparable to Felpro bolts.

 

@Mendel Leisk can you link this double hex for sale please, I can’t seem to find it. I can only find regular hex and triple square bits. I also looked at Tektons website and couldn’t find anything there either.

 

Googling:

10mm double hex

I eventually got to this on Amazon.com

An intermediate step, description found on Amazon Canada:

CTA Tools 9292 10mm Head Bolt Wrench

the manufacturer’s website page:

CTA Tools - 9292 - Toyota Head Bolt Wrench - Double Hex - 10mm — CTA Manufacturing

 

You might have to go to Snap on to get one.
Toyota won't sell them to the public. Unless you know someone that works there that will
get it for you.

 

Snap-On has one too:

Snap-on Store

There's a caution in the "Features" paragraph, regarding the triple-square.

 

no i didn’t measure them