Forum Discussion

johnmark's avatar
johnmark
Explorer
Jun 27, 2014

Exhaust manifold bolt ... advice needed!

I recently purchased a 1997 Ford Class A with a 460 engine. The exhaust manifold issues have been well documented and so I decided to put Banks headers and exhaust on it. All my manifold bolts seemed intact and so I started. The first one came out fairly easy but the infamous rear passenger bolt broke off. Only the head of the bolt broke so it is now flush with the manifold. Reading the horror stories of seized bolts and extraction nightmares and an upcoming trip in 3 weeks, I am thinking of just replacing my exhaust system but not the manifold at this point (which should lower the manifold temps). Since the bolt is flush and accessible I am wondering if it is possible to just weld a washer and nut on there and take it on my 3,000 mile trip. I have not had any leaks and the manifold looks good. I have attached a photo and would like to get some input on whether this is doable.



Another option I thought of was to just weld the hole shut since I will be replacing the manifold with headers after I get back from my trip anyway.

Any thoughts would be greatly appreciated! Thanks!
Class A
  • indyzmike's avatar
    indyzmike
    Explorer
    Jun 27, 2014
    Leave drill in the toolbox. There is no need to drill since so much of the stud is sticking out. You can put the rest of the bolts back in until your trip is over, or take the manifold off to expose the stud. Once the manifold is off, do like others have said, use penetrating oil, like Liquid Wrench or Aerokroil to soak in around the threads. WD-40 sucks at loosening bolts. Do this for a couple days by spraying a couple times a day. You can weld a nut on the stud to turn it, or use a small pipe wrench to grip on the stud. If you weld a nut onto the stud, weld it about a quarter inch from the engine and use a box end wrench to turn it. This allows more rotational force and less side, or radial force to snap the stud off. While carefully applying pressure to turn the bolt, tap on the end of it with a hammer, like pounding in a nail. The penetrating oil and the shock of the hammer should make it back out. Do not force the stud to turn, the stud sticking out is a luxury. Don't break it off. If it breaks off, THEN you go to the toolbox and get out that drill.
  • JimM68's avatar
    JimM68
    Explorer
    Jun 27, 2014
    being a confirmed do it your selfer, driving it to a shop for the minor task of freeing a rusty bolt is simply not an option.

    If you want to make that trip coming up, the best bet for now will be to put the other bolts back in and leave it. If it didn't leak before it probably won't leak now.

    When the time comes, you need to get that manifold out of the way so you have room to work that bolt.

    And then you just get to it. Use all the usual. soak in PB blaster, repeatedly. weld a nut on the end and try to work it off.
    Using an impact wrench, low torque, low air pressure, to rattle it in and out may help break it loose.
    And of course heat.

    Nice thing is, usually in a motorhome, there is lots of room. Take off the tire on that side, you can sit under there and work it for weeks.
  • PastorCharlie's avatar
    PastorCharlie
    Explorer
    Jun 27, 2014
    Drive it to a reputable shop and allow them to use the proper tool for a broken bolt removal. There is a stud removal tool that will grip the stud from the outside and prevent having to drill it.

    Soak it often and long with Blaster penetrating oil.

    The Banks intake and exhaust kit is a great upgrade for the 460 engine.
  • rgatijnet1's avatar
    rgatijnet1
    Explorer III
    Jun 27, 2014
    Sooner or later the broken bolt will have to be removed. I would center punch it and just use progressively larger drill bits until I got it to the point where I could tap the hole with the correct threads. Might as well fix it right now instead of going to a bunch of trouble with welding, etc to make a bandaid.
  • the_bear_II's avatar
    the_bear_II
    Explorer
    Jun 27, 2014
    There used to be mobile bolt extraction services. They would come to you to take out the bolt.

    From the photo it looks like ther may be room to get an angled drill in there to drill into the bolt so an extraction bit can be used.

    I've removed broken bolts in the past by using Marvel Mystery Oil (get at most auto parts stores). Heat up the engine and then squirt the oil around the bolt let it sit while the engine cools down. Then drill into the bolt insert the extractor and crefully remove the bolt. If it won't budge try more oil and let it sit over night. It once took me 3 days to get a bolt out using this method.

    Another option is to drill the bolt using larger and larger bits until there's just a shell left. Then use a metal pick to break out the bolt from the threads.

    A 3rd option is to drill into the bolt and tap it to use a smaller grade 8 bolt and washer to replace the larger bolt.
  • RayChez's avatar
    RayChez
    Explorer
    Jun 27, 2014
    IF you are a good welder you can weld a nut to the stut sticking out. Put some penetrating oil and let it set for a couple of days. You should be able to unscrew it right out.

About Motorhome Group

38,706 PostsLatest Activity: Jan 20, 2025