[drew1]

I have seen timeserts installed in engine cases, but have not actually seen or installed one. From what I saw from the installations, no tool other than a threaded fasten with jammed nuts could be used in installing, instead of a special tool.

I think helicoils are the best all around internal thread repair. As others have said, I have used on new parts made from aluminum and plastics to increase the original strength and life during hardware removing and reinstalling. Besides cross threading in use, the only failure is can they start to come out after multiple threading in and out of bolts. Removal is fairly easy, needle nose or easyout, if one is coming out or is damaged. If one comes out on the bolt or stud, no more trouble to get off than other inserts. I do not like to use them in situations where they can be long and stick through through holes. They distort when cutting to length with a cutoff wheel.


Well I said only failure, but in several times where I was not happy with myself. In a wallowed out hole and hand drill, it is hard to drill in the right place so that everything will line up, to end up the right size hole for tapping, and end up with a hole normal or perpendicular to the surface. I have had to open up holes in the mating part or put a washer to give a larger area for forces in a reciprocating pump when there wasn't much contact with the crooked bolt head. These could apply to any insert. One thing helicoil could do is lip the drill in their kits so it does not hang, but I generally do this when barely enlarging any hole.

When a good hole will be too big for helicoils there are solid inserts such as Carr-Lane make in machine screw sizes. No special tap or installation tool is needed. A problem with the solid inserts is having enough meat left if close to a edge. Keensert or Kleansert and Acme make solid inserts with the same internal thread sides with thin and thick walls. They are held in place by pins or keys on the outside diameter. No special tap is needed and a little piece of round stock comes in each bag of inserts, One end has a hole drilled for the insert to help get it started straight and the other is flat to drive it flush. If this gets lost or 'borrowed' another one can be easily made on a lathe. Although a flat screw driver can be used to thread the insert in the hole and the little driver tool used for the pins, easier and more reliable installation tools are made in case you have multiple holes of the same size.

Australian recoil interchanges with helicoil. Installation tool gets missing, one such as the recoil one can be easily made.