1.0 PURPOSE:
1.1 This instruction explains the procedure to assemble Moeller Mfg Click-Loc® inserts in typical borescope and drain plug ports. It explains the interfacing dimensions and assembly tooling and provides general information which may be useful. It is provided to assist the users in developing their own work instructions.
2.0 SCOPE:
2.1 This instruction is applicable to Moeller Mfg., (Cage 08244), part number SW31319, SW31320, SW31321, SW31405, SW31406, SW31407 and similar inserts. This instruction is for reference purposes only and is not a controlled document.
3.0 APPLICABLE DOCUMENTS:
3.1 The following links are included as part of this instruction:
Typical Port Configuration
Insert Assembly Tool
Alternate Assembly Tool
Insert Assembly Step 1
Insert Assembly Step 2
Insert Assembly Step 3
pry bar
Insert Removal
3.2 The following documents are referenced in this instruction:
MS9901
MS9902
MS33649
4.0 SYNOPSIS:
4.1 The lockring inserts are a component of a self-locking device for borescope and drain plugs and similar components. The inserts fit into specially machined counterbores added to ports that are functionally equivalent to typical design standards. Retention of the insert is by controlled interference fit between the insert and the counterbore. The insert has a scalloped form machined in the ID, which functions as detents. The flexible beam fingers of the plug act against the detents in the insert to generate a ratcheting-type prevailing torque that prevents the plug from loosening.
5.0 PREPARATION:
5.1 The port must be machined as specified on the insert drawing. See Typical Port Configuration for an example of a typical port. The counterbore diameter should have a microfinish of Ra125 or better. For ease of assembly of the insert we recommend the outer edge of the counterbore be chamfered approximately .005 – .015 inch.
5.2 The insert should be approximately .003 – .005 inch larger in diameter than the counterbore. Precise dimensions are shown on the insert drawing. Before assembling the insert both the insert OD and the counterbore ID must be checked to assure the dimensions specified on the insert drawing are maintained. This is important since there are oversize inserts available and it is possible the counterbore is already machined to accept an oversize insert.
5.3 An assembly tool is required to assemble the insert into the counterbore. We have special tools available for all of the GE90 inserts. These tools are pricey but very nicely made. We will give you a copy of the drawing if you think you can make it yourself for less cost. See Insert Assembly Tool for a picture of one. Alternatively, a commonly available conventional threaded plug such as a MS9901 or MS9902 plus a washer will also make a suitable assembly tool. See Alternate Assembly Tool for a picture. Regardless of the tool being used it is recommended that the tool be tested in the port first (without an insert) to be sure it does not bottom out on anything inside the engine, and that the thread is long enough for full engagement (if shoulder bolt type plug is used for tool).
6.0 ASSEMBLY:
6.1 The assembly operation is done at room temperature using hand tools only. No special training or skill is required.
6.2 Apply oil to the threads and shoulder (and washer if used) of the tool and to the inside of the counterbore. Oil with high film strength (i.e. STP) or waxy oil (i.e. Safety-Draw 722) is recommended.
6.3 Put insert on tool. The insert is symmetrical so it cannot be put on upside down. Thread the tool into the port by hand as far as possible. When the tool will go no further by hand the insert should be visually centered and square, properly oriented for assembly. Also at this point at least 3 full threads of the plug should be engaged in the port. See Insert Assembly Step 1.
6.4 Tighten the tool with a suitable wrench forcing the insert into the counterbore. Continue tightening the tool until the insert is completely inside the counterbore. See Insert Assembly Step 2. Loosen and remove tool.
6.4 Visually inspect the assembly operation to be sure the insert is properly installed in the counterbore. It should be flush +/- .005 inch with the face. See Insert Insert Assembly Step 3.
7.0 ADDITIONAL NOTES:
7.1 The interference fit for inserts is typically within the range of .002 – .005 inch and the nominal interference fit varies directly proportionally to the thread size. The Moeller “SW” drawing for the insert always specifies the precise dimensions required for that insert and takes precedence over this instruction. High-limit interference fits with small diameter inserts (i.e. for .625 inch threads and less) will require substantial torque be applied to fully seat the insert. Be sure the tool has enough threads so that at least 3 threads are engaged before applying a lot of torque.
7.2 If the insert gets damaged or worn it can be removed by using either a small pry bar or a blind hole bearing puller. The pry bar method is the quickest and easiest. There is a slight gap in the port immediately below the insert. Insert the tip of the pry bar into the gap under the insert and it will pop the insert right out. See Insert Removal.
Snap-On Tools makes an excellent blind hole puller set, which is part number CG40CB. This set will remove all sizes of inserts that we presently manufacture. The web site for Snap-On Tools is http://www.snapon.com and as of the date of writing of this procedure the puller set can be purchased through their web site. The puller set comes with instructions for use. If a Snap-On Tools puller isn’t immediatly available then substitute the same type made by a different manufacturer. Blind hole bearing pullers are fairly common tools used for automotive repair so something suitable should be available.
Moeller Aircraft Division Homepage
Revised March 1, 2012