How strong are retapped threads?

[dlundblad]

Originally Posted by Astro14
Originally Posted by FlyNavyP3
I also like timeserts and keyserts in addition to helicoils. Seems there is a rash of garbage helicoil kits especially the taps on the market these days, the taps just won't cut. In search of a decent kit I came across a supplier who uses US Made taps, inserts and drills, beautiful products in all sorts of sizes. I can't recommend them highly enough. The business is Thread Tool Supply out of Wisconsin. Link ---->>>> Click Here

To the OP, if it's only the first thread or two that is mangled I wouldn't be concerned. I'd me more concerned if the damage was 50% or more of the thread engagement.


Thread Tool Supply looks like a great resource!

Even places like Fastenal don't have a good selection of thread inserts. Thread Tool supply has a great selection.


I think it's pronounced Fasten-Nothin.

 

[R18Civic]

I got the engine in so if 24 lb ft and loctite don't hold I'll grab helicoils and luckily can access this area from the wheel well.

 

[nthach]

I think you should be fine, the more critical part about this is the transmission-engine interface but the position of the torque converter on the input shaft and the flexplate to TC bolts are more critical here.

 

[SteveSRT8]

Originally Posted by Chris142
Originally Posted by SteveSRT8
We are drill and helicoil fans here. Just used a GIANT one to rethread the crank bolt on a 13 6.0 Chevy. Then torqued to 100+ foot pounds plus like 45 degrees rotation! The helicoil folks have a lot of data for you if you are interested.

What do you think about time serts?



I feel just like most here, the TS's seem like a higher spec, but I can assure anyone they hold fantastic. That crank bolt we did is HUGE and requires extremely high torque and then an additional rotation that puts amazing strain on the threads. No issues even on a 6.0 powered van with a PTO setup on the crank as well as standard accessories.

 

[Trav]

The Heli Coils work fine on blind holes the problem with them is through holes eg oil pans, brake caliper mounting brackets, head bolts, etc they can "walk" during installation and removal.
I did a VW knuckle last year that had the caliper mounting cast into it then threaded, the iron is soft and easily stripped and the pins are are oddball thread 9 x 1.25, the Time Sert has a lip on it that gets recessed so installed that on the same side as the pin goes into. A perfect flush repair with even stronger threads than OE that will "walk".
Cost of the installation tools is the only drawback over Heli Coils that I can see but once you have the common sizes the inserts themselves are not expensive.

 

[R18Civic]

Both holes that go hold the bracket to the trans are stripped. Tap ran in straight after trying to walk the first few threads. Quite a bit of aluminum came out and the bolts go straight in but they're not even holding 25 lb ft. I got them as snug as i felt comfortable with after using red thread locker. As stated above the bellhousing and T/C bolts carry most of the load and are fine so I'm not concerned.

 

[The_Jeff]

Originally Posted by Hemispheres
As stated above the bellhousing and T/C bolts carry most of the load and are fine so I'm not concerned.


Yeah this, those braces do help hold weight but are also part of a noise/vibration/harshness scheme to deaden vibration and make the powertrain act as one unit.

Do you know if the first buggered threads were actually retapped or were they just chased, probably b/c the meathead mechanic started the bolts with an impact and chewed stuff out?

I assume you inspected your bolts for perfection, because if you lost three threads on the outside of your hole, you could have lost three on the tip of the bolt, and now you have problems with six threads. (Since steel chews up aluminum your bolts are probably fine if someone cleaned them up.)

If I were worried I'd run studs. I wouldn't be worried in this situation though. And because I'm a dirtbag I'd probably go through my junk drawer for slightly longer bolts then put washers under their heads until I get full yet tight engagement, LOL.