Stripped bolt hole!

Tue Aug 02, 2011 9:55 pm

Boy, if it's not one thing, it's another. It's tough working on 3 tractors at one time...hard to keep track of all the problems!!

So my problem that arose today occurred when I was installing the hydraulic line/manifold back on the SA. The middle bolt at the TC end seems to be stripped out. Just my luck...I had THREE TC units, and rebuilt (at Boss' VA Fest) the one that had a problem!!!

My question is: since I don't have the expertise and equipment to do a helicoil, can I just drill and tap this to the next larger size? There SEEMS to be plenty of "meat" on the block, but don't know if this would be a problem. Any help would be greatly appreciated. Just realized I need to check the manifold to see if there was enough room for a larger hole...will do that tomorrow.

I'll post some general progress photos when I'm not so tired, but it IS going together rather well...new tires on all round, seat, fenders, hydraulics (mostly!), distributor, exhaust manifold, etc, are all back on. Just keep bolting things back on until the shelves are empty!!

Still looking for a better grill, though...

Dale F

Re: Stripped bolt hole!

Tue Aug 02, 2011 10:11 pm

Dale, the only difference between placing the helicoil and tapping to the next size bolt is the insertion of the helicoil itself. Unless you already have the drill and tap for the next size bolt, you probably won't spend that much extra to get a helicoil kit and keep the bolt the correct size. I'm not sure what size you need, but you may want to ask at the body shop where you are doing the tractors and see if they have that size. Otherwise, most auto supply, or lots of places online.

Bob

Re: Stripped bolt hole!

Tue Aug 02, 2011 10:17 pm

BDFinch wrote: can I just drill and tap this to the next larger size?

NO, don't do that. It just makes a mess for the next guy. Remember, the next guy may be you. The only short cut I would consider is to check the depth of the bolt hole, see if a longer bolt would catch some remaining threads at the bottom of the hole. You can check the depth and remaining threads by screwing the bolt in without the manifold in place. See how far it goes in and if it seems to reach some good threads. Then find a bolt that will go to nearly the same depth with the manifold in place. Since it is the middle bolt, you can probably get away with torquing it to the low end of the normal range.

If this won't work and you can't helicoil it, get somebody to helicoil it for you.

Re: Stripped bolt hole!

Tue Aug 02, 2011 10:25 pm

Yeah, I knew both procedures involved drilling out larger holes, but I think I DO have the larger tap, and aren't the helicoil kits pretty pricey? Of course, when I look at the manifold end, there just may not be enough room for a larger hole. Won't know til tomorrow when I look.

What do suppose the odds are that of the three TC units I COULD have rebuilt, that this is the ONLY one with a problem??!!!

Dale F

PS :?: Another question: do the smaller/forward ends of the leather boots on the TC pistons get wired around the piston shaft or just left open? I already have the larger ends around the opening wired on.

Re: Stripped bolt hole!

Wed Aug 03, 2011 2:35 am

I am with Jim on this one, don't screw it up with a larger bolt!!!!!! you may be able to do as Jim said, you could use a stud if there are good threads in the bottom of the hole.

Boss

Re: Stripped bolt hole!

Wed Aug 03, 2011 5:45 am

aren't the helicoil kits pretty pricey?
Not necessarily if you know the size of the bolt you can get kit from your local automotive parts store. Your local Hardware store may carry them also. The kit should have the correct drill,tap and helicoil installation tool for the helicoil. just dont drill too deep into the casting.

Re: Stripped bolt hole!

Wed Aug 03, 2011 6:54 am

The Helicoil patent expired long ago and others make the inserts and tools in addition to the Helicoil, interchangeable in every way.

http://tool.wttool.com/search?w=Perma-Coil&x=29&y=12

Re: Stripped bolt hole!

Wed Aug 03, 2011 7:27 am

The Helicoil kits get fairly expensive in the larger ones, but the smaller ones such as 5/16, which if I remember correctly is what holds the manifold to the TC block are in the area of $25 or so. You need a kit with the drill bit, tap, coils, and insert tool. The bit is not a standard size and can be purchased separately, but may have to be ordered if it does not come with the kit. Most auto parts stores, even Autozone, stock a version of them. Amazon is also a good place to look.

Re: Stripped bolt hole!

Wed Aug 03, 2011 9:13 am

Dale:

Helicoil it. Really it isn't all that hard. If I can do it, you certainly can. Only thing you will have to do is ensure that the other orifices are protected from debris. Make a temporary cover plate say out of 1/8" masonite etc., similar to what I did when I busted a bolt off in the TC Manifold on Ellie:

Image

Helicoils are rather easy, inexpensive and the instructions are pretty clear. I think (you need to confirm that)... that it might be 3/8"-16 and if so then the helicoils will be under $20.00 for a kit including bit/STI Tap and 10 helicoils. Just check the size of the bolt with one of the good ones to be safe.

Image
Helicoil 5521-6 Thread Repair Kit 3/8-16in.

ReCoil and others make the same item. I think ReCoil and Helicoil are available at NAPA ..

Re: Stripped bolt hole!

Wed Aug 03, 2011 11:30 am

Rudi wrote: Make a temporary cover plate say out of 1/8" masonite etc. . .

For the quick solution, cover the other openings with duct tape. Those bolts are 3/8 coarse thread.

The stud suggestion is a good idea.

Re: Stripped bolt hole!

Wed Aug 03, 2011 12:36 pm

After considering things, I agreed last night with your comments about helicoiling it. I definitely like doing things right! So I might be lucky and have one coming to me today through the MAC tool guy who is also a pilot and friend.

Meanwhile, I have a shelf of other parts I can put on. The real challenge is figuring out which piece to put on next so that I do not have to take it back off to put a different part on first!! :big angry:

Dale F

PS :help: Does the leather boot get safety wired at both ends or just the large one at the base?

Re: Stripped bolt hole!

Wed Aug 03, 2011 12:52 pm

[quote="Jim Becker
... The only short cut I would consider is to check the depth of the bolt hole, see if a longer bolt would catch some remaining threads at the bottom of the hole. You can check the depth and remaining threads by screwing the bolt in without the manifold in place. See how far it goes in and if it seems to reach some good threads. Then find a bolt that will go to nearly the same depth with the manifold in place. Since it is the middle bolt, you can probably get away with torquing it to the low end of the normal range.[/quote]

I had already tried this and THOUGHT it would work. I saw that the old bolt did not appear to go to the bottom of the hole, so I carefully ran a tap down, then tried it and it seemed to be OK. However, when I was tightening it down for good, it must have had only a very slight bit of thread, and let go. Oh well, it WILL be fixed correctly.

Dale F

Re: Stripped bolt hole!

Wed Aug 03, 2011 4:47 pm

BDFinch wrote:PS :help: Does the leather boot get safety wired at both ends or just the large one at the base?


If it is like the Cub TC, it gets wired at both ends...

Mike in La Crosse, WI

Re: Stripped bolt hole!

Thu Aug 04, 2011 3:29 pm

Without seeing it myself, as I'm not sure how much "stress" is placed on that particular bolt or area, but I agree with what Jim said:
Jim Becker wrote:Since it is the middle bolt, you can probably get away with torqueing it to the low end of the normal range.

I'm wondering if a repair similar to how Carl has repaired the stripped inlets to carbs might suffice?

http://www.cleancomputes.com/Cub/Maintenance%20Tips%20and%20Techniques/Lurker%20Carl's%20Cub%20Carb%20Fixes/Fixing%20Stripped%20Threads_files/frame.htm

I've been successful using that technique on a stripped thread for a head bolt on an engine, and I've used JB Weld to make other repairs that required drilling and tapping a hole in the JB Weld repair, and it too held. There should be enough thread left that once the JB Weld cures, it should have enough bit left that the newly created threads would hold up? One thing to remember when using JB Weld is that the area has to be as CLEAN as possible in order for it to adhere, and I would wait as long as possible for it to cure to ensure it holds.

Might not work, but might be worth a shot?

Re: Stripped bolt hole!

Wed Aug 10, 2011 3:20 pm

Another happy ending!! Yes, today was a pretty good day, and some good progress was achieved!! :{_}:

I did the HeliCoil repair to my Touch Control Manifold, and have attached a link to some photos (I have attached descriptions of each photo).
http://photos.cubfest.com/thumbnails.php?album=1215

As a few of you said, it really was not difficult. I must say that it was easier after having watched this video:
http://www.youtube.com/watch?v=RFYa6sjhh_E

Thanks for the encouragement!

Dale F
Last edited by Dale Finch on Fri Aug 12, 2011 7:00 am, edited 1 time in total.