The Maxx Air covers are a really good investment. They are also made from a better plastic to hold up to the UV rays of the sun. However, I too have found that if they are left untreated in their natural state, after 6 to 10 years they too will become brittle if the camper live outside all the time. The bolt slots are the first to crack and then the cover can fly off. Having had older and now newer Maxx Air covers, I have seen Maxx Air has changed the mounting slots a little to help this cracking issue the way they mold the slot. The new ones have a reinforced area by the slot were the older ones (year 2003 - 2004 ish or older vintage) do not. This added reinforcement helps this cracking issue.
I have found that when you buy them new (or even when used and you acquired them) that spraying the inside and the outside of the cover with a 303 UV protectant when installing them can really help extend the life. Also spray the vent lid and the gasket under the vent lid while you are at it. https://www.goldeagle.com/product/30...ace-protectant
They sell 303 in a lot of places. Amazon, Walmart, Auto parts stores etc. I use it on all plastic, vinyl, roof caulking, the rubber roof on the camper. It for sure helps extend the life before the brittleness comes. Apply each time I wash the roof to the outsides of all things up there.
On the Maxx Air covers, I also have found that the cracking of the mounting slots is aggravated by the tightening of the mounting bolts. While you need to tighten them enough to not come loose, if they are over tight they create a stress point were the splits will first start. I have found this now on several of the campers I have repaired and my own original covers. To help combat this issue, I use this mounting method.
1. Buy, 4 extra 1/4-20 stainless full hex nuts per cover.
2. Place the flat washer against the slot provided by Maxx Air.
3. Gently tighten the Maxx Air provided nut against the flat washer. This "gently" means, take out all the play in the joint and then only a little more tension. This is enough to hold the cover from moving but not enough to prevent nut backing off under vibration.
4. Add the 1/4" lock washer on top of the nut in step 3.
5. Add your second added 1/4-20 full nut on top of the lock washer. Using a wrench on the bottom nut to hold it from moving, fully tighten the top nut against the lock washer. This is a double nut with a lock washer in the middle setup. This anti vibration mounting method will not come loose and will not put extra pressure on the plastic trying to keep the nuts from comeing loose. This is a very old machinery method to keep fasteners from coming loose under high vibration.
See this pic of what I described above. I have been using this now for 9 years and between the 303 and the double nut setup, no cracks and no brittleness has been seen.
Hope this helps
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC
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