Lippert through frame slide out gearbox ?

[Houston Remodeler]

One of our 3 slideouts stopped working today. When the DH presses the slide out button I can hear and feel the motor spin, but nothing happening in the gearbox mounted directly to the end of the motor. I suspect a shear pin or drift pin has been broken as there was no bad operation in the first 11 months / 9300 miles.

Web searching tells me I have to replace the whole motor + gear box + other bits as one unit. Is this true? Are there no user serviceable parts inside the gearbox?

Its under warranty. I'm just curious for next time.