Hello,
I accidentally cross-threaded the exhaust stud on the front cylinder of my motorcycle (a 2017 FLHTK). Luckily I was successful in removing the damaged stud with the head still on the bike by using a 5/16 stud extractor made by Assenmacher Specialty Tools. However, now that the offending stud is out I'm not sure what the procedure is for reinstalling a replacement stud (harley part number 10900015A). Unless I'm missing something, the installation of the stud in to the head is not addressed in the Factory Service Manual.
Does the new stud just thread in until it bottoms out in the head? Is there a specified torque value to utilize? A specific seating depth to install to?
Any insight you fellas can provide would be much appreciated.
Thanks!
Over the years I have replaced a few and I have generally used never seize on them and just screwed them in until they are hand tight.
I have seen and read on lots of forums over they years to use............
Red loctite
Blue loctite
purple loctite
grease
nothing at all
which one works and what is correct? I don't know I just know what works for me.
Quote from: Scotty on December 24, 2019, 09:56:34 PM
Over the years I have replaced a few and I have generally used never seize on them and just screwed them in until they are hand tight.
I have seen and read on lots of forums over they years to use............
Red loctite
Blue loctite
purple loctite
grease
nothing at all
which one works and what is correct? I don't know I just know what works for me.
:agree: That's all I do is install with anti seize, if you want to torque it double nut it and torque it to the exhaust flange nut torque and remove the double nuts. Using any kind of Loctite is counterproductive has the exhaust temp will burn it up and possibly give you galling problems if you ever try to remove it. Bob
If you cross threaded a steel stud into aluminum threads, fixing the buggered threads in the head needs to be your first concern.
I liked those M8 Studs when I first saw them
easy in, easy out, easy peachy as they say
I've not used any as yet but would just bottom them out gently and go from there
AND i'd use them on TC's and Evos as with the reduced hex drive they are a no-brainer
Quote from: Breeze on December 25, 2019, 04:22:43 AM
If you cross threaded a steel stud into aluminum threads, fixing the buggered threads in the head needs to be your first concern.
The cross-threading happened when I was attempting to attach the flange nut to the exhaust stud. Thankfully the damage was limited to the stud itself, and NOT the internal threading of the head.
Measure the length of the other stud and just screw in the new one to the same length. This is not a critical dimension. I use blue loctite on them myself. I believe it is an interference thread which helps prevent the stud from coming out should there be corrosion or cross threading of the nut. That said however the interference thread is diminished after the removal and stud replacement due to the soft metal. That is why I use the loctite. The nuts should have some anti-seize on them and torqued to the factory very conservative setting. This prevents pushing the gaskets in the port which blocks flow. If the exhaust leaks then retighten after running it. Still leaks look for the mismatch in the gasket and the pipe end. The factory cone shape gasket sometimes does not match the pipes flange design and a flat gasket works better. YMMV
Unless you use high temp Locktite I don't see the point in using it. Most general use thread adhesives have a max temp of 300F and maybe up to 450F. The area around the exhaust port certainly get hotter than that!
" I believe it is an interference thread which helps prevent the stud from coming out"
The Evo and TC are.
Quote from: PoorUB on December 25, 2019, 06:53:17 AM
Unless you use high temp Locktite I don't see the point in using it. Most general use thread adhesives have a max temp of 300F and maybe up to 450F. The area around the exhaust port certainly get hotter than that!
Point taken and agreed. One less thing to put chemicals on.
Quote from: 2017FLHTK on December 25, 2019, 05:29:47 AM
Quote from: Breeze on December 25, 2019, 04:22:43 AM
If you cross threaded a steel stud into aluminum threads, fixing the buggered threads in the head needs to be your first concern.
The cross-threading happened when I was attempting to attach the flange nut to the exhaust stud. Thankfully the damage was limited to the stud itself, and NOT the internal threading of the head.
Thank you. I DID read it wrong. I wondered why no one else mentioned that.
Update: I installed the exhaust stud with no drama. I simply threaded it in and seated it to the same depth as the other stud in the head. I opted to use a light coating of anti-seize.