Adding bronze bearings to the aluminum aileron or flap blocks.

The "sleeve bearing" specs are for 1/4" inside diameter by 5/16" outside diameter and 3/4 " long. Available at Granger Portland Part number 2X355. Package of three less than $5. Oilite part number AA347-04B. McMaster-Carr part number 6391K401.

In many cases out the aileron or flap surface will bend away enough to do the job without removing it but not for all hinges.

Use a 1/4 inch pilot reamer with a reaming diameter slightly less than the 5/16 in bearing. Driven by a hand drill. Use oil.

Drill from both sides of the block for a perfect clean outside but once started the reamer part will keep the hole aligned.

DO NOT REAM THE STEEL PART OF THE HINGE. LEAVE THAT AT 1/4 INCH. IT DOES NOT WEAR LIKE THE ALUMINUM.

NOTE: If you have already used the top hat STC which did ream the 2 steel ends of the hinge you can leave the top hat in the steel part to keep it at 1/4 inch. Because the clevis pin is being held on both ends there is less twisting moment so it may even work without the top hat. The major wear has usually been in the aluminum block not the steel part of the hinge. Finally if you have already reamed the aluminum for the top hat you can try using the shaft of the old top hat on the 1/4 in pilot portion of the reamer if it does not align well enough without it.

Freezing the bushing makes it easier to insert but it can be done at room temp.

Press in with our bushing press tool. Note that the bushing is too long and the next shorter is too short.

Excess must be filed off with a hand file. Keeping an old clevis pin inside helps. Run a 1/4 in reamer through to be sure.

The order of the thin spacers are. One small thin washer on each end. One larger diameter thin washer on each side of block.