How bad is this - How to fix stripped threads

[Captinjack]

I have a chinese Kama 554 tractor that I recently noticed that a couple of bolts were loose. I tightened them and found out that they were loose again in a short time. After the third time, I removed the bolts and it appears that they are stripped of the threads and I'm also concerned that the female threads are stripped as well.

This is a picture of where they come from.

It's the bolts holding down the 3 pt. hitch tank. Only the two bolts closest to the top link are stripped. I'm guessing that upward forces from the back hoe and ground engagement implements has caused this problem.

Here is a picture of the two removed bolts.

And a closer up look at the worst threads.

I appears that some of the female threads came out with the bolts.

My question is.............How can I easily fix this? I know the tank would have to be removed to do it right, but I want to try some other easier fix first and do the good repair later when I MUST remove the tank for other reasons.

I'm thinking JB weld or red lock-tight or something like that. A heli-coil insert is what would be best, but I know there is someone out there that has been there before and would have some real life experience to help me out.

I don't know whether the female threads are closed off at the bottom or whether the theads are open and a longer bolt could "go thru" making bolt length less important.

I'm planning on buying new harder bolts and giving it a try the next time I get to visit my property.

Thanks in advance for any tips. I'm thick skinned so if I'm "peeing down my leg" thinking I'm getting warmer, don't hesitate to say that I'm SOL and will have to fix it right.

 

[ToadHill]

I would use a hyle-coil (sp) you use a drill, an oversized tap and with the tool that comes with the kit you insert the coil, brand new threads, usually a lot stronger than came on the equipment. The ones I used were stainless steel.

I used to use them on my race car anytime I stripped the threads out of a hole. In fact before I built a race engine, I put a coil in every threaded hole.

 

[ToadHill]

Second point, when you cut the new threads with the tap, if you grease up the tap and drill, it will hold the iron shavings and you shouldn't have to remove the unit.

 

[6sunset6]

Helicoil would be best. Next best , there are thread rebuild kits. Essentially epoxy that bonds to the walls and a release agent on a new bolt. Shove it all in there and let it cure. The bolt will release due to the release agent. Only issue is the hole must be absolulty clean .
I have used both and both work. Helicoil kits get expensive pretty quick.
Check McMaster Carr for Form A Thread and helicoils
Thinking more I would use a helicoil. Metric thread probably Mcmaster has them

 

[AndyMA]

Heli-Coil

Heli-Coil ( HeliCoil Inserts ) Helicoils Screw Thread Inserts | Emhart.com

Andy

 

[Diamondpilot]

I did the same thing to one of my bolts on my Jinma. What I did was get the "about" same size sae stud. I then cleaned out the holes with brake parts cleaner and filled them with JB Weld then put the studs in. The JB Weld acted like a bonding agent and its held better then new. Just let it dry over night. The good thing about this type of fix is you do no take away any meat and if needed later you can drill and retap.

Chris

 

[SPYDERLK]

See if the bolts used the full hole depth. If not, buy a high speed steel plug tap of original size, and tap carefully all the way to the bottom in stages, cleaning chips alternately. Buy new bolts that use all the threads and use Loctite Thread Repair Compound in the holes. If you can get at least two more threads engaged in good metal and then combine with the loctite compound you will be able to put a reasonable torque on the bolts. The loctite will give some thread strength, but the major benefit is that it will make the hole very snug on the bolt and prevent any wiggle or turning. This will make the bolts stay torqued. The loctite is applied so as to not bond to the bolt so they will be able to be removed and reassembled when needed.
larry

 

[RickB]

Keenserts are better than Heli-coils by a wide margin.

Key lock threaded inserts - Keensert - CAMLOC - Insert

 

[Scooby074]

Keenserts are better than Heli-coils by a wide margin.

Key lock threaded inserts - Keensert - CAMLOC - Insert[/QUOTE

I agree., Timeserts are good too. ++ TIME-SERT Metric Kits ++ thread repair kits and inserts repair stripped threads damaged threads repaired threads threaded inserts for metal thread inserts for metal aluminum inserts threaded inserts for aluminum

If it was me, id probably drill and tap to the next standard or metric size, if possible.

 

[Soundguy]

I think I'd drill and tap larger as a first choice, use a thread insert as a next choice, and lastly.. if you wanted to get expensive.. drill and tap for a piece of larger allthread.. install it with a retainer fluid.. then drill that and tap for oem.. seen block repairs like that done.. worked great.. but a bit time consuming..

soundguy