SERVICE MANUAL & ICA
WIPLINE 3730 & 3900 FLOATS
Page 30
Revision K
P/N 1002551
The nose gear uses a spring leaf leg very similar to a Cessna style with a hydraulic driven truck-track retracting
mechanism. A hydraulic ram is connected directly to the truck to which the spring leaf is mounted. The rear two
rollers on the truck assembly which make up the over-center lock section follow a deeper groove in the track
casting and for this reason do not go around the corner but straight ahead to make the over-center down lock.
The upside has no mechanical lock and uses only friction and air pressure and the hydraulic lock to hold the gear
in. Magnetic proximity switches located on the right side of the actuating cylinder sense a magnet mounted in the
hydraulic ram. These can easily be adjusted from the front compartment access covers, as per Figure 6 in the
appendix. On older floats (Serial Numbers 37390 and under) the magnetic proximity switches are located on top
at the front and rear of the gear well housing and sense a magnet mounted on the hydraulic ram. These can be
easily adjusted from the front compartment access covers.
6.1 OPERATION
The nose wheel and fork pivot 360 degrees around the fork shaft and use no shimmy damping devices. A spring
loaded cam rides in a groove in the fork shaft and serves the purpose of holding the shaft in the housing and
centering the wheel during flight by means of a “flat” in the circumference of the groove. A nylon thrust washer is
located on top of the castoring pin.
6.2 WHEEL AND CASTOR
Needle type grease fittings are also used in the nose gear and retracting mechanism. There are two-needle style
and two normal styles in each nose gear. The needle styles are on the truck pivots and the standard fittings are on
the nose wheel pivot shaft housing and wheel axle.
The nose wheel main bearings should be greased using the same procedure as the main gear. A long greasing
stick or brush should be made and used to spread grease along each track in addition to the gun greasing.
6.3 LUBRICATION
The whole nose gear and retracting assembly is removed by removing the nose bumper and both hydraulic lines.
There are then six ¼ inch bolts through the nose bulkhead and two ¼ inch allen head cap screws through the
#2 bulkhead into the track castings that must be removed and the end unit should slide out. Sealant must be cut
between nose box and bulkheads.
6.4 REMOVAL
The nose gear retractor travel is preset and does not require adjustment. Side play in the gear leg can be taken
up by slightly tightening the side-play take-up bolt. Caution: be careful not to over-tighten. It is recommended that
a gear check on the ground be accomplished afterwards to make sure gear operates smoothly. The switches are
the magnetic proximity type and their adjustment is self explanatory and can be done with the unit installed in the
float.
6.5 ADJUSTMENT
