Exhaust stud question

[Mark99GT]

The manifold to mid pipe studs on my 97 are 12 x 1.75. One stud's threads were destroyed (lower passenger side) so I had to extract the stud. What a bitch that was, but I got it out. Thankfully the stud didn't snap and the manifold threads look good. I can run a 12 x 1.75 bolt all the way through the manifold.

So I got a dorman stud kit from AAP, 62mm 12 x 1.75. It was the only one I could find in the 12 x 1.75. Before installing I was just checking out the fit of the dorman nuts on the dorman studs (the new kit I just bought) and the nuts barely thread flush with the end of the stud and then stop. It's the same for both sides of the stud.

I asked the guy at AAP and he said the nuts aren't perfectly round and that's supposed to happen so they don't vibrate off? Sounds like bullshit to me. I'm very reluctant to use these as I don't see how I'll (1) get them installed all the way in the manifold and (2) I don't see how I'll get the nut tightened all the way down on the h pipe flange if it stops turning with well over an inch to go. I don't want to make a mess out of this. Am I missing something? I went to the Ford dealer and they don't sell the OEM studs or nuts anymore. Should I order a kit from somewhere else?

 

[Bullitt1448]

The manifold to mid pipe studs on my 97 are 12 x 1.75. One stud's threads were destroyed (lower passenger side) so I had to extract the stud. What a bitch that was, but I got it out. Thankfully the stud didn't snap and the manifold threads look good. I can run a 12 x 1.75 bolt all the way through the manifold.

So I got a dorman stud kit from AAP, 62mm 12 x 1.75. It was the only one I could find in the 12 x 1.75. Before installing I was just checking out the fit of the dorman nuts on the dorman studs (the new kit I just bought) and the nuts barely thread flush with the end of the stud and then stop. It's the same for both sides of the stud.

I asked the guy at AAP and he said the nuts aren't perfectly round and that's supposed to happen so they don't vibrate off? Sounds like bullshit to me. I'm very reluctant to use these as I don't see how I'll (1) get them installed all the way in the manifold and (2) I don't see how I'll get the nut tightened all the way down on the h pipe flange if it stops turning with well over an inch to go. I don't want to make a mess out of this. Am I missing something? I went to the Ford dealer and they don't sell the OEM studs or nuts anymore. Should I order a kit from somewhere else?

Odds are those are Stover nuts. They are a type of lock nut that pinches the threads on the stud so they don’t come loose. If you look at one side you should see that it isn’t round, more of an oval shape. The other side it will look like a normal nut and will thread on easily till it reaches the oval part. Use a socket and ratchet and torque as per spec.

 

[Mark99GT]

Thanks for the information. Are the OEM nuts Stover nuts? Mine are kind of rusty so they don't thread nice and smooth either way. But I can see the advantage of them for this application.

 

[Bullitt1448]

Thanks for the information. Are the OEM nuts Stover nuts? Mine are kind of rusty so they don't thread nice and smooth either way. But I can see the advantage of them for this application.

I don’t remember if the OEM ones are or not, been too long since I took mine apart. Sorry.