Catalytic Converter...

[George B]

A quality thread chaser should not remove any material, unless a crest is flattened into the thread root, but will not cut the root deeper or the crest of the down. I would not use a thread cutting die.

Anti-seize will actually yield a more accurate torque as it relieves the friction between the stud and nut.

Yes, anti-seize will relieve the friction but most torque values listed are for "dry" fasteners. There is something to be said about reducing the torque value when fasteners are lubricated. The chart below is an example of this.
https://www.engineeringtoolbox.com/torque-lubrication-effects-d_1693.html

 

[wjburken]

A quality thread chaser should not remove any material, unless a crest is flattened into the thread root, but will not cut the root deeper or the crest of the down. I would not use a thread cutting die.

Anti-seize will actually yield a more accurate torque as it relieves the friction between the stud and nut.

Agree with using a thread chaser. Chasing threads with a regular cutting for should not cause any major issues if you’re careful but a chasing die is a little more fool proof.

I do not agree with the comment about getting a more accurate torque with anti-seize. When torquing a bolt, one needs to understand if the torque spec is a dry torque or a lubricated torque spec. Most torque specs given for our vehicles are dry torque specs. If the threads are lubricated, you should actually back off on the torque applied to a bolt as you could actually over clamp the part or over stress the bolt.
https://www.engineeringtoolbox.com/amp/torque-lubrication-effects-d_1693.html

 

[wjburken]

Yes, anti-seize will relieve the friction but most torque values listed are for "dry" fasteners. There is something to be said about reducing the torque value when fasteners are lubricated. The chart below is an example of this.
https://www.engineeringtoolbox.com/torque-lubrication-effects-d_1693.html

Didn’t see your post until after I posted. Looks like you and I are on the same page.

 

[OR VietVet]

While I completely agree with the torque spec being effected by lube I also think that is more or very critical in applications like head bolts and intake bolts....etc. The torque on these exhaust flange bolts is not nearly as critical. In all my years in a shop I never torqued to spec an exhaust flange bolt and had no problems doing so. The torque spec argument is a solid subject for all kinds of other mechanical applications but here, not so much.

 

[George B]

While I completely agree with the torque spec being effected by lube I also think that is more or very critical in applications like head bolts and intake bolts....etc. The torque on these exhaust flange bolts is not nearly as critical. In all my years in a shop I never torqued to spec an exhaust flange bolt and had no problems doing so. The torque spec argument is a solid subject for all kinds of other mechanical applications but here, not so much.

Agree 100%

 

[mijohnst]

If that would create a problem for you, I will gladly accept that $250 check so you don't have to look at it.

I wouldn't even know who to sell these old ones to. It's funny now that I think about it that all the junk cars I've been crawling in and around have those catalytic converters all cut out. Duh...

Thanks for the link on the ball joint servicer tool. I usually rent one from Autozone but I might as well just buy one.

 

[JonnyTahoe]

Didn’t see your post until after I posted. Looks like you and I are on the same page.

If you have ever been to a NHRA event and watched the crew install the cylinder heads they brush on some kind of lube to each stud before installing the nuts. And its not like the studs are old or damaged they are brand new. Then they torque them.

 

[OR VietVet]

But, you can bet that they know how that lube will effect the torque and allow for that during the torque sequence/process. I too have been in the pits and watched at NHRA drag race events and seen them tear down and rebuild the entire block that was left in the frame. I went to a drag race in Independence, Mo. at the old KCIR-Kansas City International Raceway, and watched "Big Daddy" Don Garlits and Shirley "Cha Cha" Muldowney race their top fuel cars. I used to see items that their crews would throw away and spectators would rummage in the big trash barrels and save those parts.

That response got messed up real quick. It is not part of the quote.

 

[wjburken]

If you have ever been to a NHRA event and watched the crew install the cylinder heads they brush on some kind of lube to each stud before installing the nuts. And its not like the studs are old or damaged they are brand new. Then they torque them.

Yes. ARP bolts are designed to be used with a proprietary lube that they developed to provide a very consistent clamping force based strictly on torque. This is different than the typical Torque to Yield (TTY) bolts where you tighten to a prescribed torque and then turn the bolt to a prescribe angle.

 

[OR VietVet]

TTY bolts are what we used to call "stretch bolts", like a rubber band that is stretched and holds that tension with the pull of the stretch. I know the other bolts stretch a bit as well but not like the TTY bolts. That just meant I had to but a different set of torque wrenches when that all came out and an angle gauge for 1/2" and 3/8".