Had that problem on out King of the Road.
It was a Barker Mfg. slide.I found the manual
extension handle(it was mounted between the
two axles) was bouncing apparently and had loosened the mounting bolts for the motor and
gear box.It eventually broke the mounting ears off the motor/gearbox..Possibly they could
get under and look at the motor/gearbox mounting bolts.Then again,maybe some silicone on the slide rails is all it needs.
When I talked to a tech at Barker,he said that the slide should not be run against the clutch motor very long on extend and retract.In other words run it in,when it clicks(clutch) let up the button,same on extension.People tend to hold the button (click,click click) too long and put undue wear on the clutch. We don't have that trailer now and I don't have Barker's web page.Theirs may not be a Barker anyway.FWIW
2001 Volvo 770MH
2003 36'Travel Supreme 5er36RLQSO