The electric tongue jacks are noisy
in normal operation. I believe it is the nature of the beast. Mine and the few others I've heard have ALL been loud
I didn't see any lubrication mentioned in my manuals.
One thing that is a problem is getting water inside the unit. Most use a bucket, plastic wastepaper basket, or a bag over the top to keep water out. If your used unit did not come with something to keep water out, you may want to check it or have it checked.
Sherm & Terry w/rescues Steve (std Poodle) & Eydie (min Schnauzer)
2015 Jay Flight 27RLS (Camped: 102 nights 2015, 90 nights 2016)
2006 Ford F350 6.0 PSD, Lariat, 4WD, CC, LB, SRW, auto., Camper pkg.