I too have found this problem with my 8528RKSS Flagstaff 2006 unit. We were setting up a couple of weeks ago and just happened to look down and between the wheels and on the shaft off the motor which drives the slide out, what did I hind? It wasn’t a Jolly old man and 8 tiny reindeer. But a broken bolt half of it was still hanging there. I found a replacement bolt and fixed it. Then when we got home this week it was broken again so I replaced it with a stronger bolt. And like Darrell our tube had play in it. Then we tried it several times to make sure it would hold and so far its still hanging in there. Glad to see we weren’t the only ones having this problem.
I have a 2008 Flagstaff 831bhss and have had the same thing happen. The dealer (in Arkansas) said to replace them with grade 8 bolts. Said they should be grade 8 from factory. I replaced them and still had breakage. Talked to dealer in Shreveport, LA and they said the bolts were the wrong . The shoulder of the bolt should extend completely through the 1" tube , no threads inside the tube. I have purchased new bolts but am waiting until the current bolts break to replace with longer shouldered bolt.
Hope this fixes the problem. Maybe it will help you to. Remember to get grade 8 bolts.
O.K. After checking with lippert (who makes the slide out ) found you are NOT to lube rails and gear cogs (voids warranty)........Great to not have that info on purchasing unit. Found they stated to have "shoulder bolt" 1 1/2" long. Well I measured and you need unthreaded portion to reach through shaft/square tube area. I used a 1 3/4" which clears rotation of unit and puts all pressure on area not cut with threads. So far so good. Also check there website as they say to manually operate unit you must disconnect power or electrical feed back may damage motor, (voiding warranty) another thing you aren't made aware of when purchasing unit. Good luck.