We are original owners of the Domani DF300 fifth wheel and have been since late 2007 (2008 model). Our slide out rollers were replaced about 2 years after purchase due to a Carriage Recall. It appears that the original rollers carrying the slide wore through quite easily. When ours were replaced, the rollers were already exposing the bearings inside I would imagine this is the problem you're having.
We are in Southern California and have a formerly authorized Carriage repair facility, before Carriage went belly up, who do all our repairs. If you are close or would like their info just PM me or hit me up on the forums here and I'll provide it for you.
Best of luck!
Ray
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Ford F250, Super Crew, 4X4, 6.0 Liter Power Stroke Diesel with a Reese hitch.
2008 Carraige Domani DF300 fifth wheel
***And a 2011, Lance 825 Truck Camper!!***
RALLIES ATTENDED 2