On the road from Alabama to VT we were in NY and went to bring in the main slide and the kitchen end chucked a bit and made a noise. We have had no main slide issues so I went to see what was up. The slide rectangular tube drive system that was made by Lippert (now owned by Power Gear) used a pair of Delrin rollers in the system to support the drive tube. Housed between two of the rollers is a welded bar type gear on the bottom of the rectangular tube that is used to keep the two slide drives, one on each end of the slide, in sync. They used a square tube as an axle and a round gear coupled to the bar gear as a rack and pinion system. See Photo.
My problem was one of the Delrin Rollers cracked and broke. I called Mike at BCS who had them in stock and had him ship me 4 new ones. They are reasonably priced, ask Mike for PN 520014. BCS was a great help and I would not hesitate, and would prefer to go there to have this repair and slide maintenance done, if within any rational striking distance.
I spoke with Sean and he says those rollers do break from time to time, I would guess age is a factor. Obviously the kitchen end of the slide puts more stress on the rollers and if I was at BCS for work anyway, I would consider changing out 10 year old or older Delrin rollers at the heavy end of the slide as a part of maintenance and have them clean and lube the mechanicals.
I have read about slide maintenance and typically they tell you to use just a dry lube which I have done yearly before I head out. Sean shared that they have used white lithium grease on any friction point and the gears for many years and oil some of the shaft ends where they pass through the rectangular tubes. I think that is excellent advice.
I always try and use the best materials so I went looking for a grease that would not wash out, not be too messy to work with, and in particular one that was compatible with Delrin and Super Lube (which I am a fan of) with teflon was an excellent choice. I also looked for a highly regarded dry lube and found that Protect All made one which seemed to have more body to it then some. I travel with a can of spray chain lube onboard which I used to handle the shaft contact point oiling job. Links below.
https://www.amazon.com/Protect-All-40003-Slide-Out-Protectant/dp/B001FCB1JG/ref=sr_1_1?ie=UTF8&qid=1468350777&sr=8-1&keywords=protect+all+slide+out+dry+lubehttps://www.amazon.com/Super-Lube-41160-Synthetic-Translucent/dp/B0083R1FME/ref=sr_1_2?ie=UTF8&qid=1468350847&sr=8-2&keywords=super+lubeThe steel gears had some rust on them which is why I think the greasing is a very good idea. I wire brushed any gear rust, also any rust on the rectangular tubes that would contact moving surfaces. I greased the gear teeth putting it on with a putty knife and a short bristle brush and also where the rollers ride on the square shaft with the Teflon clear grease. I then sprayed the sides of the inner square tubes while extended that ride against some pads in the outer housing square tube. I also greased the bolt shaft that the rollers rode on when I had it out replacing the rollers.
Sean shared this procedure for changing the roller if you ever face this on the road. I milled a 3ft length of 4x4 to mate with the extrusion shape of the aluminum at the bottom of the slide, basically cut out a 1 1/2 inch by 1 1/2 inch L shape removing one 4x4 corner. This is the shape that accommodates the bottom fin on a 2002 Marquis slide bottom aluminum extrusion, others may vary.
To replace the rollers bring the slide in about 1/3 of the way leaving just enough room to work. Drop the coach so it is not resting on air, and turn off 12V and AC power to the coach for safety. Center the 4x4 under the vertical bracing to the left of the door that houses the air unit if those are the rollers you are changing. Jack just enough until the rollers will rotate by hand. Remove the bolt and replace both rollers. I used a two ton car floor jack to do the lifting. Air up and move the slide out and lube it. If you do nothing else consider this lube procedure.
My slide goes in and out so easily and smoothly now, that it is now clear to me that without the lube and grease on the gears and the better dry lube, that I had some binding during slide travel that I did not recognize was taking place. This has made a world of difference. Given our main slide is so heavy and large that I think it requires more then the customary dry lube as Sean has recommended. Photos of the broken Delrin roller and the roller and rack and pinion arrangement in the slide drive tube. The cleaning and lube should take about an hour and changing the rollers, if you need to, is about an hour job. I was able to get the slide in and back out once while it was riding on just one roller but I do not think with the loads involved, that one roller would last very long so I am carrying two spares.
I would like to thank BCS again, in particular, Mike in parts, and Sean in service for all the support they gave me and other Beaver owners in times of trouble on the road. Top shelf outfit, wish they were closer to home. Hope this helps.
Later Ed