SPL SUSPENSION PARTS - Page 13

DaveC113 · 05-10-2024, 10:15 PM

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 · 05-11-2024, 04:33 AM

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 · 05-11-2024, 05:29 AM

Just ordered a set....great catch!

Sephx1 · 05-11-2024, 11:21 AM

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 · 05-11-2024, 03:03 PM

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 · 05-12-2024, 08:14 AM

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

Thanks all!

cdrptrks · 05-12-2024, 11:56 AM

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

Quote:

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 · 05-12-2024, 02:44 PM

Quote:

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.

Slurpee · 07-26-2024, 08:45 AM

So I tackled some of these installs along with my MCS 2WNR.

The SPL rear upper arms were very easy to install. Since my struts were already coming off, I had more room with the coils removed. Still needed to use a wrench on the nut with the frame in the way and a socket on the head. Also had to torque the head and not the nut, no room to get a socket on the nut.

The rear camber lockout was more of a pain. I could not get the arms into the inboard position, so I put the washer in the middle position on both sides. I messed up one side, the washer flats were not in full contact with the arm so I needed to redo it. Witness marked everything, so we'll see how I did later on. I increased camber from -2.4 to -2.1 since my outsides barely looked worn after Ozark. Alignment shop said there was no issues getting -2.1

The front tension rod also was much easier than anticipated, I was dreading this one. I bought the harbor freight ball joint separator and a Dremel, but I hit the nut with the newest M18 1/2 high torque impact and both sides fell out after the nut was loose. I also only have 7500 miles on the car.

I also decided to go the route of loosening the aux coolers instead of cutting the bolt out. I think this was the right way to do it, as it was pretty easy. Having quickjacks made this much easier I'm sure, as I had plenty of room everywhere. Removing the wheel liners is a bunch of 7mm bolts, a couple of 10mm, and torx screws. After removing, the 3 bolts on the aux coolers are relatively easy to loosen with a wrench. The brake deflector is also 2 pieces, at least on my 2020. You can pop out the piece that is blocking the bolt for more access to remove the bolt. On the driver side, I had to fully remove the aux cooler bolts to get enough room to pull the bolt. Driver side I didn't.
I was a bit confused on how the install with the SPL tension rod to knuckle, so gave them a call. You want to use the least amount of anti dive spacers on the bolt, which in my case was 2 of the big spacers and 1 small spacer. 2 big spacers there wouldn't be enough threads to fully tighten the nyloc nut.

Speaking of which, torquing those nuts was very difficult. 110 lb ft on lubed threads was pretty hard. Had to use a 12mm 1/2 breaker bar on the hex on the bottom of the bolt to hold the bolt in place while tightening the nyloc nut.

kropscamaro16 · 07-26-2024, 10:42 AM

i installed full spl parts kit first and then the mcs coilover kit later had no issues

Slurpee · 07-26-2024, 11:13 AM

I have SPL front tension rods, SPL upper arms, and SPL toe arms. Feels like an absolute dart after the alignment. There is some oscillations on bumps and dips in the road, so need to increase the damping, but wow, can't wait to get on track.

Edit: 3760lbs without driver and 1/8 tank of gas (forgot to fill up, rip). Puts her at 4045lbs with a full tank and driver.
Based off of this post, https://www.camaro6.com/forums/showp...26&postcount=2 I have shaved off 69lbs.

05-10-2024, 10:15 PM	#169
DaveC113 Drives: 2018 Camaro 1SS 1LE Join Date: Sep 2018 Location: Front Range, CO Posts: 1,977	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. __________________

05-11-2024, 04:33 AM	#170
Kezos Drives: 22 1SS 1LE Join Date: Mar 2021 Location: IL Posts: 18	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 __________________ 2022 1SS 1LE M6 Summit White

05-11-2024, 05:29 AM	#171
khcoaching Drives: 2021 1SS 1LE Join Date: Nov 2020 Location: 98548 Posts: 633	Just ordered a set....great catch! __________________ Follow my build - https://www.camaro6.com/forums/showthread.php?t=594295

05-11-2024, 11:21 AM	#172
Sephx1 Drives: 18 ZLE, 18 SS1LE, 16 SS, 23 ZL1 Join Date: Jan 2021 Location: Phoenix Arizona Posts: 427	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. Last edited by Sephx1; 05-11-2024 at 11:34 AM.

05-11-2024, 03:03 PM	#173
wakespeak Drives: 2020 ZL1 1LE Join Date: Sep 2012 Location: Austin, Texas Posts: 1,347	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! __________________ 2020 ZL1 1LE [Moroso SC Expansion Tank, otherwise stock]

05-12-2024, 08:14 AM	#174
Osbornsm Drives: 2018 SS 1LE Join Date: Mar 2018 Location: Illinois Posts: 665 View My Garage	What's the replacement bolt part # here. I'm seeing conflicting info. Thanks all! __________________ 2018 Camaro SS 1LE - 2011 370z - 2004 VW R32 - 2000 Civic Si Mods: Rotofab, Nick Williams 103mm TB, MSD IM, Kooks 1 7/8 Results: 470 hp / 447 tq

07-26-2024, 08:45 AM	#177
Slurpee Drives: 2020 ZL1 A10; Shadow Gray Metallic Join Date: Sep 2020 Location: Chicago Posts: 225	So I tackled some of these installs along with my MCS 2WNR. The SPL rear upper arms were very easy to install. Since my struts were already coming off, I had more room with the coils removed. Still needed to use a wrench on the nut with the frame in the way and a socket on the head. Also had to torque the head and not the nut, no room to get a socket on the nut. The rear camber lockout was more of a pain. I could not get the arms into the inboard position, so I put the washer in the middle position on both sides. I messed up one side, the washer flats were not in full contact with the arm so I needed to redo it. Witness marked everything, so we'll see how I did later on. I increased camber from -2.4 to -2.1 since my outsides barely looked worn after Ozark. Alignment shop said there was no issues getting -2.1 The front tension rod also was much easier than anticipated, I was dreading this one. I bought the harbor freight ball joint separator and a Dremel, but I hit the nut with the newest M18 1/2 high torque impact and both sides fell out after the nut was loose. I also only have 7500 miles on the car. I also decided to go the route of loosening the aux coolers instead of cutting the bolt out. I think this was the right way to do it, as it was pretty easy. Having quickjacks made this much easier I'm sure, as I had plenty of room everywhere. Removing the wheel liners is a bunch of 7mm bolts, a couple of 10mm, and torx screws. After removing, the 3 bolts on the aux coolers are relatively easy to loosen with a wrench. The brake deflector is also 2 pieces, at least on my 2020. You can pop out the piece that is blocking the bolt for more access to remove the bolt. On the driver side, I had to fully remove the aux cooler bolts to get enough room to pull the bolt. Driver side I didn't. I was a bit confused on how the install with the SPL tension rod to knuckle, so gave them a call. You want to use the least amount of anti dive spacers on the bolt, which in my case was 2 of the big spacers and 1 small spacer. 2 big spacers there wouldn't be enough threads to fully tighten the nyloc nut. Speaking of which, torquing those nuts was very difficult. 110 lb ft on lubed threads was pretty hard. Had to use a 12mm 1/2 breaker bar on the hex on the bottom of the bolt to hold the bolt in place while tightening the nyloc nut. __________________

07-26-2024, 10:42 AM	#178
kropscamaro16 Drives: 2016 1ss camaro Join Date: Feb 2016 Location: 909 Posts: 9,917	i installed full spl parts kit first and then the mcs coilover kit later had no issues __________________ 16 1SS NIGHTFALL GRAY METALLIC WITH NPP #BECAUSERACECAR #SAVETHEMANUALS

07-26-2024, 11:13 AM	#179
Slurpee Drives: 2020 ZL1 A10; Shadow Gray Metallic Join Date: Sep 2020 Location: Chicago Posts: 225	I have SPL front tension rods, SPL upper arms, and SPL toe arms. Feels like an absolute dart after the alignment. There is some oscillations on bumps and dips in the road, so need to increase the damping, but wow, can't wait to get on track. Edit: 3760lbs without driver and 1/8 tank of gas (forgot to fill up, rip). Puts her at 4045lbs with a full tank and driver. Based off of this post, https://www.camaro6.com/forums/showp...26&postcount=2 I have shaved off 69lbs. __________________ Last edited by Slurpee; 07-26-2024 at 11:24 AM.

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