Our 3580 is 2 years old last week. We have put about 8000 miles on it:
The problem: doing an inspection I found:
a) the rear axle springs on the off door side had started to "cascade" - it had about a 3/4" offset between 2nd and 3rd leaf.
b) the shock absorber had been rubbing the tire on the same axle: clearance between tire and shock on that axle side are a lot closer than on other axle.
c) found where the front axle, on the same side, the shock had never been connected (it was in the bracket but no evidence of nuts,washers, etc.) The shock is bent
d) on the door side found bent shock.
e) ALL the shocks are mounted at an odd angle to function correctly.
Had a local shop inspect and retorque (6 of 8 bolts), remove unattached shock (had to do while trailer was "hanging" to get enough clearance in the brackets). Started a conversation with Heartland about the problem, sent pictures to them and Lippert and the result was: here is a shock to replace the one that was not attached. Period.
Took a 200 mile trip and checked the bolts: two needed to be retourqued. Enough is enough so I arranged to have everything replaced from the frame down. Had the trailer weighed : neither WHEEL had over 3000# on it, so a total of 6,000# per axle (7,000# axles)
Upon removal of the Lippert axles and springs, we found:
1) the rear axle was 1/2" shorter on the off door side between the brackets and the backing plate. This was the one that was rubbing the tire.
2) ALL the shocks were bent and had been totally compressed from the original date of installation: you could not compress and remove the shocks (or install the new one sent by Heartland) as the distance between the frame bracket and axle bracket was not sufficient to remove/install a fully compressed shock. Once you hung the trailer from the frame and took pressure off the axles, the axle would drop and the shock would extend and could then be removed. One shock had threads so screwed up it had to be cut off.
3) The spring hanger bolt for the rear axle off door side in the Trail Air center bracket was worn flat on 2 sides. This is the axle the cascaded springs were found on originally
I can not tell you how disappointed I am in this. I have owned 7 RV's in the past 30 years+ and have NEVER had an issue like this and the effect this will have on my future buying pattern.
I replaced the suspension with the MorRyde IS and disk brakes. The ride is better, the brakes are AWESOME