Helicoil kits

[Anonymous]

Hi folks,

I'm wondering if anyone has used a Helicoil kit before, and could give a wee bit of info? Myself and my boyfriend are currently trying to get a recently acquired 1980 GSX 400 back on the road but have run into a problem. When removing the sump plug, we discovered that at some point in the past the thread has been stripped, and the previous owner has repaired it using a Helicoil kit. Unfortunately, now the Helicoil has come out, and won't go back in. So the current plan is to buy another Helicoil kit and do the same thing again. The problem with this is that we're not sure what size you order the kits by - the sump plug is 14mm, and the hole has been drilled out to 16mm, so do we need a 14mm kit, or a 16mm one?

Thanks,
Tina

[spots25]

you buy the kit for the size of BOLT that you need to put in it. 14mm is the one you need, but what thread pitch?

[SqDancerLynn1]

Before you buy & expensive helicoil kit Check into getting a new oil pan

[DaveDanger]

The problem with fairly large helicoils is that they tend to not stay in place. The helicoil installation procedue requires you to drill any hole oversize, so that when you insert the helicoil in place, it brings the hole/thread size back down to original. If your actual plug threads are 14mm (and some specific thread pitch, coarse or fine), then that is the size of helicoil kit that you order. The outside of the helicoil will probably be 16mm, the inside will be 14mm, which is what you desire. The entire helicoil kit is required, unless you already have one, in which case you only need to buy a new helicoil insert. The kit has a drill bit in the specified larger size, a threaded tap to cut the new larger threads (to accept the helicoil insert) and a special driver tool that is required to screw the helicoil insert in place. Once an insert has come out, there's no way to reuse it. I suspect that a helicoil kit in that diameter will be a tad pricey. Just guessing at a metric fine pitch of 14mm x 1.5.. a kit lists on the net for about $36.00 USD. The second problem you're going to probably run into is the thickness of the material (oil pan) you're repairing. Helicoils work incredibly well in thicker material, because there's a lot of the insert going in, and gripping the material. It tends to stay put and lock itself in very well. In a thin material, there will be very few threads of the insert being gripped, and as a result, it will grip much less tightly. For something as critical as the oil drain plug, I'd be awfully concerned about it wiggling loose and falling out while riding. A replacement oil pan would maybe cost more and be more initial trouble to replace, but I think it'd do you better in the long run.

[ptm]

I agree that replacing the pan (actually on the 400 I think it's just a round plate that has the drain plug in it) would be better, but it could take a while to find one. If you do get the helicoil kit (or if someone on the forum would give you just the insert - the kit comes with several of them) put 'red ' thread lock on the threads on the pan (after they're throroughly cleaned) before putting the helicoil in - that will help. As Dave mentioned it isn't very thick so there aren't many threads for it to grip.

The last coil on the insert has a tab that sticks in toward the center and the kit has a tool that uses the tab to screw the insert in. Once it's in you break off the tab. Without the tab it's impossible to get the insert to thread into the hole. With one that big you could use needle-nosed pliers to grab the tab on a new insert to install it.

Try posting in the 'parts wanted' section and see if anyone has a spare insert they will give you. The whole kit will be pretty expensive.

[Red_Phil]

OK I have a plan.
I'd still have to take the sump pan off the bike,but hopefully this would work longterm and not require finding a new sump.

find one of these (or similar) at a plumbing merchants.
http://www.plumbworld.co.uk/259-1676

Fit it through the hole in the sump, drilling it larger if needed.
A couple of O-rings should stop leaks.
find an end cap that fits the threads to cap the fitting.
Finding an end cap shouldn't be to hard as plumbing stuff all tends to be
in standard sizes.


Your thoughts?

[Pete Logan]

Looks like a good plan, though obviously you'll be checking the inside clearances cos that thing's gonna take a little more room by the look of it.

I was gonna suggest simply welding an appropriate size nut over the hole on the outside.

Pete

[Red_Phil]

The fitting mounts with the flat plate with the 2 tangs on it facing inwards.
It looks like it'll poke into the sump less than the current bolt does.

Any suggestions on what to use to seal it?

[Pete Logan]

Ah Right (Never looked inside mine). Just my guess, but I would think standard rubber/plastic water seals would do it. If not, then maybe crush copper seals if you can find some the right size, or make some flat copper seals.

Or maybe just a liquid gasket maker.

Hopefully someone's got a better idea

Pete

[mixongw]

The fitting mounts with the flat plate with the 2 tangs on it facing inwards.
It looks like it'll poke into the sump less than the current bolt does.

Any suggestions on what to use to seal it?

The handy-man's secret weapon (no, not duct tape)... JB Weld.

[Anonymous]

General consensus seems to be that this was not a wise use of a helicoil, so we're going to go with a solution that doesn't involve one. Will let you all know how it goes. Thanks for the advice.
Cheers,
Tina.

[Planecrazy]

An even better choice than JB Weld (which is always a good choice), is HTS-2000. It looks like welding rod, but you use it kind of like solder to fill aluminum cracks, holes, etc. It has a lower melting point than the aluminum (by 500 degrees) and is stronger.

What's really nice about this stuff is that you can build the thickness up in the area the plug needs to be and reduce the chance that it'll ever strip out again.

Check out http://www.aluminumrepair.com/. There are similar products, like Alumaloy, but HTS-2000 claims to be more forgiving when used with even slightly contaminated materials.

Good Luck!
Steve 8)