NT 40x48 Tounge Extension - Attachment Advice

[Glenn Butcher]

I just acquired my extension tubing - 3/16 gauge, 2 1/2" x 2 1/2" x 6', ~$37.00 at a local steel outlet. I intend to attach it to the frame at the existing tongue holes with bolts that go through the entire tube, with nylock nuts. For those who've done it already, is that enough to secure it to the frame? I'm contemplating also incorporating square U-bolts through the cross-members, but is that overkill?

[bobhenry]

That's all I did but I ran my tube all the way to the rear so I could use it as a receiver for a bike carrier insert.

Taking it full length takes the strain out of the second cross member.

If you have ever seen a badly overloaded short tongued trailer the second cross member is sagging downward.

[KCStudly]

My preference for thru bolting would be to install anti-crush sleeves. The preferred method is to drill thru an oversize hole and install steel tubing (or pipe) that has an ID that suits the bolt size. The OD of the sleeve and/or the hole in the box tubing can be chamfered to enhance weld penetration.

If welding is not an option (...which sounds really silly for me to type, because welding is always an option; you just might have to work harder and pay a little to make it happen) you can cheat; just drill one side of the box tube to accept the sleeve and leave the other side hole to fit the bolt. The sleeve will be captured between the inside of the tongue tube and the underside of the xmbr w/o welding; but I would go out of my way to get the sleeves welded in.

Without crush sleeves, I would rather see the square U-bolts w/o the thru bolts. They won't weaken or crush the tubing the way a thru bolt would. Don't try to fit them all the way thru the 'C'-channel. Just drill thru the bottoms and put the nuts inside of the channels, that way you don't have to worry about crushing the channels and having the U-bolts loosen.