Tapping stripped threads

[featherbedder]

Originally Posted by OTRA15

[emphasis added]

Did you take into account how thin the receiving part may be? Are you sure you were into the "frame?"

I have built racing motor cycles, stock cars engines, fabbed many projects in steel certified mechanic, extensive wood work, have many tools metal and wood including lathes for both welding equip, many tools only shops have, so I no dif. whether in frame or other. Also have much exp. w/helicoil, rivnuts etc. have worked with tools for 80 yrs. my exp. is vast not newbee.

[Rich W]

Well I got the other 3 out today, more or less. It's pretty ugly. The one most forward, front left was tapped into the A frame. I drilled it out, with no small amount of effort. This Irwin extractor kit to remove broken bolts leaves a lot to be desired. The first bit snapped off and the next size up doesn't do much without a lot of pressure. I was able to drill up far enough through the bolt that I think I can get one of the grade 8 bolts in there. The other 3 feel solid but I haven't put a wrench on them. I can see threads.

The 2 most forward on the right side were both in the A frame steel...solid. I was able to drill both of those deep enough to get a punch in between the bolt and edge of the frame to push the remainder of the bolt out of the way. I plan on doing the same with these two as with the forward one on the left side. Put a grade 8 bolt in and turn madly. I will then remove that one, grease a fresh one with waterproof grease and insert.

If I can get these reassembled and installed back on the AS, I am never taking them off again.

[Melucy2airs]

I have the same problem I still need to address for my AS rear stabilizer, the machine bolt just keeps turning without biting. I have never used a rivnut before but I think it would be a great addition to my toolbox.
Just ordered a box of rivnuts (stainless steel) from Amazon and will tackle the problem this weekend. Thanks for the suggestion!

[AldeanFan]

Originally Posted by ROBERTSUNRUS

Hi, it's been quite a few years now since I had some bolts pull out of my stabilizers. I drilled 1" holes in my belly pan so I could slip a boxed end wrench in the hole with a nut in it. I only had to do the very inside bolts because that is where all of the pressure was. I just taped over the holes with silver duct tape. They will never strip out again.

I did this too, I used nyloc nuts.

[Rich W]

Originally Posted by ROBERTSUNRUS

Hi, it's been quite a few years now since I had some bolts pull out of my stabilizers. I drilled 1" holes in my belly pan so I could slip a boxed end wrench in the hole with a nut in it. I only had to do the very inside bolts because that is where all of the pressure was. I just taped over the holes with silver duct tape. They will never strip out again.

Originally Posted by AldeanFan

I did this too, I used nyloc nuts.

If you have to take them off again to clean and paint, how will you do it? Take the tape off and reverse the process?

[ROBERTSUNRUS]

Originally Posted by richw46

If you have to take them off again to clean and paint, how will you do it? Take the tape off and reverse the process?

Hi, Yes.

[ROBERTSUNRUS]

Hi, warning! Using well nuts or nutserts can be very bad "IF" the hole is too large and the crimp is not quite tight enough. Nothing worse than trying to tighten or loosen a bolt while a well nut or nutsert spins.

[Rich W]

I thought about that. Mine will be solid in the hole and I'll add waterproof bearing grease to the bolt. It won't be tightened too much because it just needs to support it during travel or sheer support while parked.

[AldeanFan]

Originally Posted by richw46

If you have to take them off again to clean and paint, how will you do it? Take the tape off and reverse the process?

Basically yes.
I actually riveted patches over my access holes so I’d have to drill out pop rivets.

My stabilizers are aluminum and galvanized and they look ok after 43 years so I won’t be painting them anytime soon.

[Rich W]

Originally Posted by AldeanFan

Basically yes.
I actually riveted patches over my access holes so I’d have to drill out pop rivets.

My stabilizers are aluminum and galvanized and they look ok after 43 years so I won’t be painting them anytime soon.

The inner arm of mine looked like aluminum but a magnet sticks to it. The paint was scratched and faded. There was no rust on 2, the other 2 had a little rust. The black brackets bolted to the belly looked the worst, rusted and paint coming off. The pads were all rust. BAL doesn't make these anymore and the new ones require drilling and self-tapping or tapping. I think they are a C-note each.

[gspies2]

use helicoil repair kit for original bolt size., comes with correct tap and indicates required drill bit size. You drill larger hole, tap and inset the helicoil and insert original bolt

[Rich W]

Originally Posted by gspies2

use helicoil repair kit for original bolt size., comes with correct tap and indicates required drill bit size. You drill larger hole, tap and inset the helicoil and insert original bolt

Thanks, Gspies2. Greetings from central Kentucky and welcome to the forum.

I have thought about using the helicoil. I've got the rivnuts so I'm going to try those. Either of these solutions would work for the back stabilizers because they are tapped into a cross member. The front 2 stabilizers front 2 bolts (there are 4 in the outer end of the bracket) were tapped into the A frame box. Getting those out was impossible and I tried to drill them out with reverse drill bits in a kit from Irwin tools. The bits kept skating, even if I tapped a pilot dimple, so it's not a clean hole. I've ordered some new carbide drill bits to see if they will do better. I think if I can get either of those holes to line up with the bracket and use a grade 8 bolt to tap then it should hold it just fine.

[tjdonahoe]

Originally Posted by richw46

I have a machining question. The OEM 5/16-18 trilobular (Tap-Tite) self-tapping bolts holding the stabilizers to the belly have stripped the original holes' threads. The bolts are fine, but the holes are now mostly stripped. These are bolts that didn't break off, they are the ones I was able to completely remove and are mostly in good shape. (I broke off 4 bolts but I was able to remove the first one and oddly enough, the threads seem to still be there.)

I bought 5/16-18 grade 8, full thread, flange bolts to use as replacements for the OEM bolts and they screw in but won't seat, they just turn. I'm thinking to drill out the holes for all of them and use larger self tapping bolts, or maybe drill out the holes and tap them to a larger size, like 3/8-16. I'm not sure that 3/8-16 is sufficient to have enough grip for a replacement or if I should go with something like 7/16-14. In either case, the holes in the stabilizers will have to be drilled out too because the 5/16-18 barely make it through.

Any machinists out there to answer my query?

Metric. 1 size larger.

[Rich W]

Originally Posted by tjdonahoe

Metric. 1 size larger.

Are you a machinist, perchance? I have another question.

The metric size may be a solution to the rear stabilizers, but I'm having problems with the holes in the front ones, particularly on the right side. I can't drill them. I used reverse bits from Irwin to drill the bolts out. The bits skated even though I put a dimple in the broken bolt. As a result the drilled out area is not the original bolt area but most of it, plus part of the A frame next to the bolt. This is pretty thick steel.

Right now I'm stuck. On the left front I have installed the stabilizer with 3 of the 4 outside bolts, one of which is in the A frame. The 4th hole still has the bolt remnant and I can't seem to drill it out. I think 3 bolts are pretty solid.

On the right side the 2 front A frame holes are open, I can get the Irwin 5/16 reverse drill bit into them but a 5/16 grade 8 bolt just strips threads. A DeWalt carbide 5/16 tries to drill but snags on a rough edge and the drill just goes to maximum torque (rattles but doesn't drill) because it can't turn anymore. It chipped a small bit off the drill bit.

The weather is turning colder for a couple of days so I'm just thinking about what to do next. I've been using a cordless DeWalt but I'm going to take my old Black & Decker 3/8" corded drill over there to see if I can make any headway.

Question: Any other possible ways of drilling out the holes/bolt? If the corded drill can't make headway I'm thinking I need to take it to an RV repair shop and have them drill and tap them.

[ITSNO60]

Drill first with a smaller bit, go slow and use cutting oil. Going fast will not only heat up and ruin the bit but it will "work harden" the bolt you are trying to drill into. Keep your hand on the back of the drill motor when you push so the pressure is in line with the bit like a drill press, this will help to keep from snapping the bit. Holding a drill like a gun makes it too easy to snap smaller bits.

[ITSNO60]

edit: I may have mis-understood. Do you mean you got the bolt drilled out but there is a snag in the hole that is stopping your RH bit? When this happens I just punch the drill in and out quickly while it is on full speed till it clears the snag, you may have luck with the corded drill if your cordless can't do it. Beware when you punch it in, the snag will try to follow the flutes and pull the bit in, be ready to pull back on it. If you go in too slow you will chip the bit.

[Rich W]

Originally Posted by ITSNO60

Drill first with a smaller bit, go slow and use cutting oil. Going fast will not only heat up and ruin the bit but it will "work harden" the bolt you are trying to drill into. Keep your hand on the back of the drill motor when you push so the pressure is in line with the bit like a drill press, this will help to keep from snapping the bit. Holding a drill like a gun makes it too easy to snap smaller bits.

Left Side:
3 holes threaded, 1 bolt remnant broken off. I used a punch to make a dimple in the center (best as I could). I used a reverse 5/16 Irwin bit using WD40 as cutting oil in a cordless DeWalt drill, slow speed. The bit never got hot, heavy pressure on the back of the drill. I was able to drill out some but not all of the bolt. I used a small chisel and was able to break off some of the bottom of the bolt.

I tried a day later with a 5/16 carbide bit (DeWalt) but I didn't have my WD40 with me. This DeWalt bit has a starter point tip. I think that tip isn't digging into the bolt and it's not drilling on center because the first (Irwin) bit kept walking, despite making a dimple in the bolt. I think the remaining 3 bolts will hold the stabilizer but I wish I could get that 4th one in.

Right Side:
The 2 most forward bolt holes are mostly clear. I can get a smaller size bit into the holes well past the length of the bolt. I used a punch to hammer these bolts out of the way, forcing them left. I think that remnant on the bottom of the bolt is what my carbide tip is catching on and stopping. I tried tapping with grade 8 bolts but they just stripped. These are drilled into the A frame, some thick steel.

Originally Posted by ITSNO60

edit: I may have mis-understood. Do you mean you got the bolt drilled out but there is a snag in the hole that is stopping your RH bit? When this happens I just punch the drill in and out quickly while it is on full speed till it clears the snag, you may have luck with the corded drill if your cordless can't do it. Beware when you punch it in, the snag will try to follow the flutes and pull the bit in, be ready to pull back on it. If you go in too slow you will chip the bit.

I can try the corded R/H drill (no reverse on this) but I have a corded hammer drill too. Would this be a better choice?

[ITSNO60]

I know just the Dewalt bits you are talking about, that tip will not dig in and they will break. You can also buy the Dewalt carbide bits without that tip but in this case I would just use a cheap jobber bit to punch through that snag.

[Rich W]

Originally Posted by ITSNO60

I know just the Dewalt bits you are talking about, that tip will not dig in and they will break. You can also buy the Dewalt carbide bits without that tip but in this case I would just use a cheap jobber bit to punch through that snag.

Here's my current bit collection of good bits. I have smaller ones that are junk bits, none large enough to do the job. I can ruin one of these. The largest Irwin is 5/16 and I think I used that to get as far as I have, it is probably dull now. I think it's the one that goes all the way up but the DeWalt doesn't; snags. I need to take some notes and pictures on my next trip out there. I'm getting confused on which hole is which. I just know the right 2 snag. I think the left one just won't drill out.

[RFP]

Originally Posted by gspies2

use helicoil repair kit for original bolt size., comes with correct tap and indicates required drill bit size. You drill larger hole, tap and inset the helicoil and insert original bolt

The thickness of the material is too thin for helicoil installation.