Page 23 - Aeronca 7A Interactive Service Manual

LANDING GEAR GROUP

GENERAL
The Aeronca Champion is equipped with the now famous Aeronca hydraulic-spring type landing gear
assembly.

CASE FRAME
The oleo case frame assembly, Part Number 4-540, incorporates the frame or cylinder which houses the
spring and hydraulic unit. This frame attaches to the fuselage at Station 2 and 2½ using bolts AN6-15 front
and AN6-27 rear. This welded tube structure is X4130 steel, not heat treated. A bronze bushing is pressed
into the lower end of the case frame for the bearing surface of the oleo piston action and can be replaced
when worn oversize. THIS REPLACEMENT SHOULD NOT BE ATTEMPTED BY ANY OTHER THAN
AN AIRPLANE MECHANIC.

OLEO PISTON ASSEMBLY
This assembly consists of spring, plunger, and hydraulic oil retaining cylinder. It is important that this
cylinder be full of oil.

To fill the oleo, (using Teleo oil or any good hydraulic oil), prop up the front of the ship, remove the
connecting bolt at the axle strut and raise the oleo up to a level where you can remove the brass screw plug;
then pour in oil until it is completely filled. If it is necessary to change the graphite packing, release oleo
unit from the oleo case assembly by removing the bolt at the top of the oleo case.

Drive bushing out of spring retaining washer and remove retainer and oleo spring. Pry the plug at the top
of the cylinder loose and remove old packing. Press the new into place around the piston rod and replace
parts. Extreme care should be taken in replacing the oleo in the oleo case. Be certain that the bolt passes
through the retainer at the top end of the oleo. If this is not done, the oleo will fall out when the aircraft
takes off. This can be checked as follows: Lower one wing until the wheel on the opposite side is clear of the
ground. This should be done by having one or more persons grasp the wing struts at their attaching points
to the wing and then pull down. One other person should then stand on the raised wheel and test with his
full weight. If the wheel drops down and the oleo pulls out of the case assembly, the bolt holding the oleo
unit in the case has not passed through the provided hole in the retainer. On the front lower end of the oleo
case assembly, there is an alemite fitting. Apply grease with a gun until it is forced out of the bottom of the
oleo case assembly.

AXLE STRUT
This assembly consists of X4130, not heat treated, steel tubing, welded and formed to accommodate the
wheel assembly. It is attached to the fuselage center landing gear yoke at the upper end and to the oleo
assembly at the lower fitting as shown on the landing gear assembly drawing. It is not advisable to attempt
straightening this axle if it is bent more than ⅛” from a straight line.

All landing gear parts are interchangeable, left and right.

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