Stripped threads

Mrakulous · #1 (**permalink**) 10-20-2009, 01:04 AM

The threads one one of the exhaust stud holes is stripped out. My dad told me to use safety wire to make a "redneck" helicoil, but it didn't work. I just got it all back together and i really don't want to take it apart. Will a helicoil work in there because i don't see how a tap can get all the way into it. Or can I use some kind of epoxy type stuff to "glue" the stud in place.

Thanks,
Mrakulous

bandito · #2 (**permalink**) 10-20-2009, 01:12 AM

Can you tap it out to the next bigger size, say from a 5mm to a 6mm.

xlite · #3 (**permalink**) 10-20-2009, 10:09 AM

Why not use JB Weld? Just kidding, that is ridiculous.

Re-tapping to 7mm or 1/4" is the only reasonable fix.

bandito · #4 (**permalink**) 10-20-2009, 11:14 AM

If tools are an issue a sheet metal screw the right size works.

xlite · #5 (**permalink**) 10-20-2009, 05:54 PM

Quote:

Originally Posted by bandito

If tools are an issue a sheet metal screw the right size works.

If your talking about self tapping sheet metal screws that would be a bad choice. Unlikely you'd get out of the driveway. Allthread or a bolt with head cut off makes more sense.

Drewd · #6 (**permalink**) 10-23-2009, 01:53 AM

timesert thread repair worked great for me several HT engines.

bandito · #7 (**permalink**) 10-25-2009, 09:48 PM

Xlite Ive had some pretty crappy cars back in the day the kind youd pay $300 for and drive them till they died. I remember a few times where a 8mm bolt would strip out doing a water pump or what ever and I used a sheet metal bolt, the kind where it has huge threads on them to repair it. They dig into aluminum really well especially if the thread is just bigger than the hole. Doing it right? No but tools and money were an issue, I used what I had and it worked. I wouldnt do it now but its an option.

bairdco · #8 (**permalink**) 10-26-2009, 01:44 AM

timesert kits are what, 80 bucks? might as well buy a new engine.

a-dam · #9 (**permalink**) 10-26-2009, 02:18 AM

Quote:

i don't see how a tap can get all the way into it

There are blind taps (also called bottom taps) that can thread a not-all-the-way-through hole.

My $20 Harbor Freight tap & die set has gotten a lot of use, mostly on aluminum. At that price you could buy two sets and chop down the tap on one set to make your own blind tap, if the need arose. When chopping it, you would have to be careful not to overheat and ruin the hardness of the steel.

xlite · #10 (**permalink**) 10-27-2009, 05:58 AM

Quote:

Originally Posted by bandito

Xlite Ive had some pretty crappy cars back in the day the kind youd pay $300 for and drive them till they died. I remember a few times where a 8mm bolt would strip out doing a water pump or what ever and I used a sheet metal bolt, the kind where it has huge threads on them to repair it. They dig into aluminum really well especially if the thread is just bigger than the hole. Doing it right? No but tools and money were an issue, I used what I had and it worked. I wouldnt do it now but its an option.

It might be possible to get away with it on a car water pump but considering the difference in vibration, shear, and tensile forces on a HT exhaust unlikely to last more than a few minutes. Look how many fine thread studs fail. Sheet metal screws? Yeah..right!