[DaveC113]

I just replaced the outboard toe link bolts, both it and the inboard bolts were slightly untensioned. The issue with the knuckle bolt io it's in single shear and the bolts are not specific to the application and have a very long threaded length. So the bolt sees single-shear loading in the threaded area of the bolt. Further, a TTY bolt is often weaker than a regular bolt because it's intended to permanently elongate. Once used it's yielded permanently, and thus weakened.

From my armchair, this is sloppy engineering. I think using a double shear type attachment to the knuckle seems obvious, or at the very least don't put single shear forces into a threaded TTY bolt.

In any case, the ARP bolts do fit well and have a far less threaded length. Looking at the old bolts. the ARP bolts have just enough threaded length for the application, which will make the bolt last much longer before it reaches it's fatigue limit vs a threaded bolt shank. This, and the high (180 ksi) strength and manufacturing quality of the ARP bolts are the reason I used them.

TTY is an inexpensive and reliable method of assembly, but their use may dictate some differences in the design of the part vs regular bolts that I am unaware of, and replacing TTY bolts with regular bolts without a thorough engineering analysis may not ne a great idea. If the ARP bolts break and I survive I will report back, but I think the ARP bolts likely have an order of magnitude or two longer fatigue life vs OEM.

[Kezos]

Checked mine, one was a half turn under 75 ft lbs other was a about a quarter turn under. Kinda scary, just did a 900 mile round trip to the track. Got a new set of GM bolts but will probably order ARP ones.

Thanks for the heads up

[khcoaching]

Just ordered a set....great catch!

[Sephx1]

I’ve been running all SPL on the rear of my ZLE for a while now. As far as the outer toe bolts, I will add that when I first heard of them breaking (from SPL tech) I went to replace them and I could see the bolt wobble slightly as I backed it out. If they are bending they are weakening especially if you are taking them out and reinstalling them. SPL recommended using new OEM bolts, at least when I talked to them about it 6 months or so ago.

The biggest problem I have is no matter which of the best alignment shops in my area that I use, none of them seem to understand that the hiem ends need to be able to move freely and not bound up by being clocked against each other. The first thing I do after any alignment is put the car on a lift, get my 9/16 wrench and 3/16 Allen and fix this.

[wakespeak]

Bolts replaced, torqued to 74 ft/lbs + 105deg (I think - the bar stopped at around there). Old bolts not anywhere near hand tight but also not at 74ft/lbs. The old bolts were about 1.5mm longer than the replacements. TTY is single use!

[Osbornsm]

What's the replacement bolt part # here. I'm seeing conflicting info.

Thanks all!

[cdrptrks]

This is the bolt part # I used (with orange threadlocker) and it has stayed tight for the last 5 track days since then:

"11609598 is the outer toe link to knuckle bolt part number. You will need one for each side."

https://www.camaro6.com/forums/showp...&postcount=154

Originally Posted by Christian1LE

Just checked mine before my next track day and it was loose. Saved me, ty.

I have spare ones in hand so it was easy to fix.

You're welcome. That's scary. Do you remember what torque value you used on those reused bolts originally when installing the SPL arms?

[Christian1LE]

Originally Posted by cdrptrks

This is the bolt part # I used (with orange threadlocker) and it has stayed tight for the last 5 track days since then:

"11609598 is the outer toe link to knuckle bolt part number. You will need one for each side."

https://www.camaro6.com/forums/showp...&postcount=154


You're welcome. That's scary. Do you remember what torque value you used on those reused bolts originally when installing the SPL arms?

I used 74. Just cranked them 100 degrees more and I'll keep an eye on them.