crznZ06

I was installing a new set of shocks on my car today, and I'm pretty sure that I cross-threaded one of the mounting points on the back of the car. I'm going to go and find a tap and try to clean the threads out, but what is the solution to this issue if the tap doesn't work? Am I really going to have to cut a hole through the trunk to fix my f_ck up?

Thanks!

froggy47

I "think" it's a captured nut that you screw into & IIRC access is pretty good. You could either run a tap (correct size) & see if you can get the bolt to tighten or maybe use some red loctite if you don't think it'll tighten

or

my preference, tap it one bigger and up size the bolt.

Replace the original bolt even if it looks ok, those threads will be compromised also.

POST BACK what you do, to help others.

crznZ06

Thank you. I'm going to try the tap tomorrow morning.

Anyone else have any tips? Thanks!

crznZ06

So, I tried a cheapie tap from Harbor Freight, M8 x 1.25, but it didn't feel or look like it was seating properly as I tried to thread it into the mount. The shank did not seem to be seating perpendicular to the face of the mount, so I didn't force the issue. I'll try a better quality tap.

Does anyone have any other suggestions?

Thanks!

0Randy@DRM

Try to get the tap to work. If that doesn't work there is a helicoil that would work. http://www.stanleyengineeredfastenin...ands/heli-coil

Randy

crznZ06

Thanks Randy! I'll give it another shot.

froggy47

Sometimes a tap will straighten out as it cuts into the hole. But you need to lean on it a little to keep it straight.

Han Solo

Be leary of this "lean on it" advice.

I had the same thing happen and broke a tap off in the captured nut. Talk about a pain in the ****! I managed to build my own tap extractor and got it out. At the end of the day I got the threads cleaned up and was able to tighten the bolt. I used a new bolt as suggested above.

froggy47

"Lean on it a LITTLE" was the full advice.





If it's clearly wanting to track in on an angle, you can't just keep going or you end up with an oblong hole.

victorf

If you have a set, start with the one having the most taper. Which is the No.1 taper starter. Stay away from the bottoming finish tap.

Gently feel your way, maintain perpendicular, unless female thread is grossly crossed. No. 1 taper tap will have a chance - gotta have patience.

If the internal threads were grossly crossed, even if the cleaned up is successful, once damaged internal threads are compromised. So you have to decide.

crznZ06

I really appreciate all of the advice and tips from everyone. I'm going to look into finding a set of taps, as the one I got is probably a finishing tap. Are there any particular brands to look out for? Thanks again!

UstaB-GS549

You can get a decent tap at Ace Hardware or McMaster-Carr

http://www.mcmaster.com/#standard-taps/=uu92le

Make sure it is a starting tap and the pitch is correct. There are several M8 pitch taps available.

Don't let the tap go in crooked. Feel your way in.

victorf

I don't ever go cheap on tools, you get what you paid for. Good taps are made with quality tool steel, last a lifetime, especially when you go easy along with cutting fluids. I normally go with US, European or Japan made!

HTHs!

crznZ06

Thanks everyone! I forgot about Mcmaster Carr. It's actually somewhat local to me, so I'll be heading there shortly. In the event it works, I'll take some photos and post them for the next person who rushes things in the driveway!

crznZ06

Do these look like the right McMaster part numbers for the job?

8305A19 M8 x 1.25 starter tap
8305A39 M8 x 1.25 through hole tap
2546A25 tap driver

Also, are any of these alignment tools worth getting? I can't think of how they would actually be attached to the face of the shock tower to guide the tap.

http://www.mcmaster.com/#tap-aligners/=uuljst

Thanks again!

Bad Karma

For thread repair in an area that is more structural/sees a lot more stress I am always wary of a heli-coil fix, just doesn't seem string enough and I've seen the pull out. I was pointed to this year's ago as something stronger by a guy building some high stress turbo engines.

http://www.timesert.com/html/mtrcsert.html

v8pwrd

Another option is to use a thread forming tap. These do not cut threads they form threads by displacing the material. I've used them successfully to repair a damaged hole.

froggy47

1. What are the specific advantages of TIME-SERT over Helicoil or coil style inserts?
TIME-SERT® is a thin wall, solid bushing, self locking insert with positive placement.

TIME-SERT® inserts are a thin wall solid bushing insert. This guarantees easy installation and allows for full load use of tapped hole, ensuring protection against stress and vibration.
TIME-SERT® inserts are "timed" internal to external which gives a very thin wall thickness which means TIME-SERTs can be installed in areas of limited space and clearance.
TIME-SERT® being a solid bushing insert gives it added strength, easily withstands high temperatures without damage or deforming. TIME-SERT® inserts have no prongs or tangs to break off or deal with down in the hole, which can be a problem in deep holes.

TIME-SERT® inserts are self-locking having an actual locking feature which will prevent them from coming out when a bolt is removed. On installation the bottom few internal threads of the insert are cold rolled to expand into the mating external threads of the base material locking the insert in place.

TIME-SERT® inserts have a flange, which will give them a positive placement on installation for “accurate specific depths”. This ensures that the insert does not wind down into the threaded hole.
Thin wall, self locking , solid bushing insert with positive placement .

Customers have asked if they may also use Loctite® adhesives for additional strength. Yes you may due to the solid wall design. There is no danger of loctite passing thru the threads of the insert and locking up the bolt as in coil types. Time-Sert inserts are used in Aluminum, cast iron, steels and even some hard plastics. MADE IN THE USA
Click here for close up tooling video

rbl

Here is my 02¢

I think you are getting OD's with replies.

If the tap you have has a blunt end it is the wrong one. You need the one with the pointed end and it can be had at Home Depot, Lowe's or Ace hardware. there is nothing "magic" about McMaster.

Be sure you have the thread properly ID'd so you know for certain what it is and have the correct tap.

As Froggy said you will have to lean on it a little to get started. This simply means that you have to get it started straight and it will requite some pressure and holding. More than likely the first thread is damaged and that will not let it start straight unless it is forced to do so.

Once/if you can get past the first thread you should be able to run it through. Best case is you will have a weaker attachment. However, for a top bolt to the shock I am not so sure that matters all that much.

I agree that heli-coils are a poor choice compared to what is available today. The Timesert is superior but not as easy as it looks for the application. You need the kit and they are about $70 on Amazon.

I think you will find that the nut is quite hard and it will be hard to drill it straight and or tap it straight. If it is as hard as I think it may be you can easily snap the tap, no matter who you buy it from, as they are quite brittle. If you do then you will have another problem bigger than the original.

Start the tap and keep it straight with some pressure. Turn it just a touch and back it up. Turn, back, turn, back and so on. Keep it lubed. Try to barely make a cut before you relieve the pressure and do it again. If you can get it started you may need a thru hole one as well. Just buy a cheap one and grind the end down and run it through since you have good threads at that point.

Report back with your success

froggy47

I do all mine (well not THAT many - I'm careful) with a cheap HF set.

Not sure how you crossed it, but ALWAYS get as many turns as you can by hand before you put a ratchet on.

I was in a hurry one time and used an air wrench on a sway bar bolt into the sub frame.

NEVER TRIED THAT AGAIN. But I did clean it up with a cheap tap.