Cam Bolt Question

[Shoeless]

I have a question on my cam bolt installation. I started to clean one of the cam bolts up on the wire wheel before my installation and decided to test fit it on the frame. Started to tighten the nut by hand and it froze up way before getting tight.

https://i.imgur.com/Ilg7F6p.jpg

https://i.imgur.com/RfAqbO1.jpg

I thought this was a bit odd, so I checked all of them and they all seem to “bottom out” well before hitting the offset washer. I then flipped the nut over to check the threads and it will barely even start on the bolt.

https://i.imgur.com/mf95m86.jpg

Am I missing washers for all my cam bolts, do you think I have the wrong ones, or am I missing something?

[beeman]

I'm guessing wrong nuts

[SerpantFL]

I will defer to the class A machinists out there, but when I worked on the Brown and Sharpe single screw machines, we could set the depth of the threads on the pieces we made. Maybe the nut is defective in that the threads don't run completely through. Someone didn't use the go/ no go gauge on that nut? Have you checked the thread on thread gauge to determine English or Metric? My (USA made Harley had metric items, shhhh.)

[NAZ]

Are you sure your kit didn't come with Stover nuts? These are a type of lock nut that have a slight crimp on the outer end.

[Shoeless]

I'm guessing wrong nuts

I hope not, I just went through all my donor stuff and no other nuts available.


I will defer to the class A machinists out there, but when I worked on the Brown and Sharpe single screw machines, we could set the depth of the threads on the pieces we made. Maybe the nut is defective in that the threads don't run completely through. Someone didn't use the go/ no go gauge on that nut? Have you checked the thread on thread gauge to determine English or Metric? My (USA made Harley had metric items, shhhh.)

Go figure a Harley with the metric hardware. I do not have a thread gauge to double check the threads. I wouldn't think defective as they came in my list of donor stuff that I ordered. Wouldn't be the first time I ran into issues, but it made me think different model number than the ones I should have. BTW the bolt has an O above a 10.9 stamped on the head of the bolt.


Are you sure your kit didn't come with Stover nuts? These are a type of lock nut that have a slight crimp on the outer end.

I think we have a winner here. I'm not 100% up on Corvette hardware and didn't want to wrench on these things incase I did have the wrong stuff. I just went in the garage and put a little more torque on a couple of them and they seem to tighten up as expected.

Thanks for the help NAZ, the forum saves me again :D

[beeman]

More torque is always the right answer!

[rev2xs]

Hey guys,

this is actually a defect with the chassis, common issue which will cause alignment creep if not sorted.

Crash sells cambolt washers which sorts this as does Shane. So in a nutshell, the stock cambold washer needs to be a little thicker as to make sure it seats proper due to the seating area being narrower on teh GTM's chassis vs a stock Corvette. Or something like that i believe.

Crash's solution is really good for setting up the precise wheel alignment you want (especially when it comes to changing aligment often for track use), and Shane's solution is ideal for the street (not saying Crash's isnt) and a little cheaper.

[lance corsi]

Sounds like it could be a locking nut. I wouldn't run a tap thru it for that reason.

[VRaptor SpeedWorks, LLC]

Yes, these are steel lock nuts....they are designed this way so they won't come loose. If you have a Gen II, they should tighten down nicely.....I would recommend roughing up the powdercoat under both sides of the bolt (under each cam washer) so that the cam washers won't "slip" so easily and will hold their position once torqued down.

[crash]

I agree that it looks like a lock nut issue you are experiencing there. The kits we sell come with bolts that have more threads on them to deal with the second issue of them not tightening down and bottoming on the threads. If you have this issue and insist on using the cam washers, then adding a thick washer under the head of the bolt should do the trick. IIRC this is how Shane goes about it?

[Shoeless]

Many thanks for everyone chiming in here. Especially Shane with scuffing the powder coat as this knowledge is only out there for guys that have worked through this many times.

Another question. Which orientation is best for adjustments once the car is all together. Bolts inserted from the inside of the control arm out, all pointing rear,...different orientation for the fronts vs. rear?

Crash, maybe this is my inexperience and not asking enough questions. Is your shin kit a replacement for these cam bolts? Hey

[VRaptor SpeedWorks, LLC]

All of the cam bolts need to be installed with the head of the bolt toward the center of the control arm. If you don't do this, then once the car is together, you won't be able to get any of them out if you would need to remove a control arm.

As for cam orientation, going from memory, once we get the car aligned, the rear cam bolts end up slightly inboard.....standing behind the car looking at them, the LH bolt would be at about the 1:00 position and the RH bolt would be at the 11:00.

For the front suspension, we run the rear cam bolt all the way outboard as far is as it will go (max caster), then the front ones end up similar to the rear suspension bolts with both of them slightly inboard.

[crash]

Yes the http://www.myraceshop.com/Alignment_Shims.html replaces the bolts and washers that are stock Vette. You would still use the same nuts you currently have.

[beeman]

GM C5 torque specs btw..
Lower Control Arm (Fr) Cam Bolt Nut 145 N·m 107 lb ft
Lower Control Arm (Rr) Cam Bolt Nut 95 N·m 70 lb ft
Is anyone going higher torque?

GM Parts #
Bolt: 10254819
Cam washer: 10254818
nut: 11516382

[Shoeless]

All of the cam bolts need to be installed with the head of the bolt toward the center of the control arm. If you don't do this, then once the car is together, you won't be able to get any of them out if you would need to remove a control arm.

As for cam orientation, going from memory, once we get the car aligned, the rear cam bolts end up slightly inboard.....standing behind the car looking at them, the LH bolt would be at about the 1:00 position and the RH bolt would be at the 11:00.

For the front suspension, we run the rear cam bolt all the way outboard as far is as it will go (max caster), then the front ones end up similar to the rear suspension bolts with both of them slightly inboard.

Geez, one would think this would be pertinent information that should be in the build manual LOL.

Thanks everyone for chiming in. Definitely gaining knowledge and making me more at ease as I continue my build.

[VRaptor SpeedWorks, LLC]

That is what we end up with based on the alignment specs I use. A lot of guys are using much different alignment specs than me, so the cam bolts are going to end up in different positions.

[Shoeless]

GM C5 torque specs btw..
Lower Control Arm (Fr) Cam Bolt Nut 145 N·m 107 lb ft
Lower Control Arm (Rr) Cam Bolt Nut 95 N·m 70 lb ft
Is anyone going higher torque?

GM Parts #
Bolt: 10254819
Cam washer: 10254818
nut: 11516382

Hey Beeman,

My Gen2 manual says front cam bolts 125 ftlb, rear cam bolt 107 ftlb, and rear bolt 71 ftlb.

[NAZ]

Since you have a conflict with torque values you should check the size & property class against a generic torque chart for a sanity check. Or if your manual shows the size and property class of the fasteners it's calling out torque values for that would also give you some level of confidence. If you use the wrong torque value it can result in either applying too much torque which can damage the fastener or insufficient clamping force which can result in the adjustment you set moving on you.