Just recently I've heard a rather loud "clunk" from my trailer when stopping or accelerating. I have an '04 180 Horizon and trailer. I'd always had this since new, but now it was even louder. Decided the brakes needed bleeding. After looking at the master cylinder and all, I decided on a new MC, rather than diagnose and repair the old one as it was a dirty mess. During removal, one thing I found is that the second nut that connects the dampener rod to the coupler plate was missing. Either it was never on, or came off. Went to Tie Down Engineering website and found that I needed repair kit 47267K for my Model 70LP button latch hitch. Ordered one from Champion Trailers. It all arrived, and I started putting it back together. First thing is that plastic cuff wouldn't fit, so off it goes (didn't have one originally anyways). Tried to slip it all back into the coupler body and it won't quite go. Pulling it all out and looking underneath I see there's a tab hanging down from inside that the top of the master cylinder slips in to. Well, the tab on the new master cylinder is too large to fit. What the heck?
So I go back to the Champion website, and now I see the disclaimer "***Cannot be used with Four Winns, Tracker, or Ranger trailers. Warranty will be voided if used on these brands of trailers*** Ok..that one's on me, but I don't have a warranty anymore. I called Champion and asked them why it would void a warranty. They said it's because Four Winns modifies some of the parts. Going back and looking at the old MC, I see the MC top mounting plate is way thinner that the new one. Carefully, I remove the new one (saving the gasket) and switch them out. Put it back together again and this time it seats perfectly.
Now it's time to put the rollers in. Rear one goes in and works. Front one doesn't move. Pull it out and compare it to the original one. The new ones are machined probably just 1 or 2 mm longer, so it won't work. Glad I saved the old pieces. Put the old one back in, and all is good. Bleed the brakes and no "clunk" at any time. Smooth as silk.
Now I go back to the Tie Down Engineering website and look at their repair kits. Most of them are missing the top MC plate! They give you a gasket and you're to switch the plates.
Bottom line...save all the old pieces. You may need them later. Anyways, hope someone can use this info in the future.
Rick