B45 wrote:Hi All,
I'm at the planning stages for a long term restoration of a basket case Harvard IIB. Quick query regarding L/G seals. I am thinking of overhauling the L/G first whilst I collect the missing airframe items but am concerned over the shelf life of the overhauled items. Will the seals dry out if not used or, once overhauled, can they sit on a shelf indefinitely? Also, any tips for the overhaul?
Cheers,
Mike
As long as you have fluid in the strut, Nitrogen in the strut (not air with contains moisture) and have grease or other lubricant (I use Aeroshell #6 or7) on the seals and lower bearing it should last and be no different than one installed on a flying A/C.
However, the top of the upper strut has the down lock pin as a part of the . The lug it locks against is mounted onto the wing spars. There are fits and clearances involved between the two so you might want to do that with the strut disassembled. Also the Alum trunnion that the strut mounts to can't be slid onto the pivot shaft as a complete assy unless the outer wing is off and the end ribs of the center section are removed.
There are many different thickness shims on the gear pivot shaft where the Alum Trunion that the gear strut bolts into. You have to fit the upper strut into the truion and tighten the 4 bolts. Rotate the lock pin to engage the lock lug. Make measurements and remove the upper strut and trunion. Mess with adding,subtracting or changing shims on the pivot shaft and them repeating the process. Its easier to do if its just the upper strut.