RC Guys Super Decathlon ARF Assembly Manual page 13

Install a wheel collar on the axel, then the wheel pant with the wheel
inside, add the second wheel collar. This is a bit tricky as they all
must be properly positioned together on the axel.
Center the wheel in the pants and tighten the lock collars. Make sure
the wheel turns freely.
NOTE: You may need to enlarge the hole in the bottom of the wheel pant for the wheels to turn freely.
Using the supplied hardware, 2 x 6­32 bolts and washers, secure the
wheel pants to the gear legs. Make sure these are very tight.
NOTE: Be very careful that you do not cross thread any of the
bolts as this may loosen the T nuts.
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