By Russ and Tiña De Maris
A few months back we talked about an annoying phenomenon that travel trailer RVers sometimes face: hitch clunk. Slop in the hitch system allows the trailer a bit of room to move on the hitch, and as you pull forward from a stop you may hear a “clunk!” and perhaps another when stopping. Writer Dave Helgeson offered a suggestion on resolving this nettlesome noise.
Well, as everyone declares, there’s more than one way to quiet a clunk. Reader Mel Goddard weighs in with a solution of his own, one that he feels might even be a simpler fix.
When Mel’s hitch became a problem child, he whipped out a feeler gauge and took a measurement of the space between the hitch “stinger” and the receiver. He discovered there was .064″ of space for both side play and top-to-bottom play. His solution?
“I made two .060 shims from steel strapping, drilled a pin hole in one, and use them to stop the slop. Notice also in the photo that there is a .040 shim between the head and the ‘clevis’. This is due to the fact that there is play between those two, and cranking up the bolts will not close the gap.”
Still, Mel had a concern. He determined that the gap could close, resulting from a loosening up of mounting bolts — which could be a serious safety issue: a fatiguing of the bolts. To handle this eventuality, Mel replaced the bolts. “In lieu of the Grade 5 hardware (120 KSI), I used Grade 8 bolts and nuts (150 KSI) to clamp the assembly. Reason? Just because!”
When installing the hitch, Mel greases the shank with heavy grease “because it still moves a little, and anything that moves should be lubed.” He falls back on an old military adage, “If it moves, oil it; if it doesn’t, paint it; if it talks back, salute it.”
What about a hitch pin? Mel uses an aircraft bolt that he specs out as MS: 21250-10, with a DSC: 97-10, along with two MS:2002-C10 washers, which he lightly snugs. And yes, because the operation could be a bit messy, Mel advises you wear gloves when you install your hitch.
Mel reports he’s used this setup for six years without problems. He concludes, “I believe in the old saw: K.I.S.S. (Keep it simple, silly.)”
Thanks, Mel, for yet another look at doing something.