CONTINUOUSWAVE

While setting up a bunk trailer I've noticed a couple of things that worry me.

On my single-axle roller trailer, where the rear crossmember joins the side rail of the trailer, the crossmember has a bent over part (a tang) that rests on top of the trailer frame and a single bolt that holds it in place. The bent over part appears to be bending up and coming off the frame. This will result in only the bolt holding the cross member onto the frame of the trailer.



On a tandem-axle used trailer I bought, I've inverted the crossmember mounts to get the crossmembers to sit lower on the trailer frame. The crossmember and the load on them will only be held in place by a single big bolt on either side, as seen in Figure 2.



Q1: Will [the method of attachment on the tandem-axle used trailer described above and illustrated in Figure 2] be enough to support the weight of my 1988 Revenge 20 W-T?

[Moderator's note. I have revised the illustration marked as Figure 1, based on an elucidation of what the image was supposed to be illustrating. I have revised the caption for Figure 1 to explain what is to be illustrated by the image. I have deleted six posts in this thread in which the purpose of the image originally shown as Figure 1 was explained. The attachment method for fastening the crossmember to the frame shown in Figure 1 is not used for the method of attachment for a different trailer, a tandem-axle trailer, which is shown in Figure 2.]

The tandem-axle trailer crossmember and bracket look identical to the hardware and design of LoadRite's products: I own several LoadRite trailers.

The single bolt is sufficient to hold the load presuming it is the original factory bolt.



Note there are two slots for bolting the crossmember to the bracket.

See:

https://www.loadrite.com/trailer-parts/frame-components/crossbar-brackets/crossbar-hanger-bracket-5-frame-galvanized-2/

Q2: in [Figure 3] what is the purpose of that rod shape welded to the back of the bracket?

On my [used tandem-axle] trailer that rod piece is positioned at the bottom of the trailer's [longitudinal frame] and will not add any weight carrying capacity.

My [used single-axle] trailer had the brackets reversed and that rod-shaped part sat on top of the trailer side rail leading me to believe its purpose was to create extra weight carrying capacity.

floater wrote:...trailer had the brackets reversed and that rod-shaped part sat on top of the trailer side rail leading me to believe it's for extra weight carrying.

I think if the welded-on rod sits atop the longitudinal frame, it helps bear the weight onto the frame, rather than relying on just one bolt to carry all the vertical loading. The orientation would 180-degrees flipped from as shown in Figure 3.

The [bracket is oriented so] welded-on rod sits on the underside of the frame rail.

Why does the rod sit under the frame? Is it to keep a cross member from going upwards when you go over a big bump in case the bolt fails? I just see no use for that rod in the position it's in.

In [Figure 1] there is a 9/16-inch rusty bolt that holds on the crossmember bracket. Above that bold the bracket [tang] curves over the top of the trailers side rails. This set up give the crossmember two support point: the bolt as one and the tang bearing on the frame. The [tang] is stretching upwards signalling to me that the bracket and possibly the bolt are weakening. [That sign of weakness that I perceived by the bending of the tang in the single-axle trailer was the reason I bought the used] tandem axle trailer.

floater wrote:Why does the rod sit under the frame? Is it to keep a crossmember from going upwards when you go over a big bump in case the bolt fails?

The rod must either help the crossmember shifting upward or shifting downward, depending on how it is aligned with the frame.

I would presume that the intended orientation of the crossmember bracket as shown in Figure 3 is to be installed as shown below in Figure 4, which corresponds to the narrative description by PHIL T given earlier.



When installed as shown in Figure 4, the bracket has three options for the mounting height of the crossmember; the crossmember can be be located below the height of the longitudinal frame. This is useful for setting the height of keel rollers that will be attached to the crossmember and for bunk brackets that will be attached to the crossmember

I have [the same cross-member mounting brackets as the ones illustrated and discussed above] on my trailer. I was told [by someone unidentified that] the welded rod [on the mounting bracket] was to keep the cross member from turning inside the frame.

My trailer is an [all floppy] roller trailer.

I thought [the trailer manufacturer] would put the [welded-on ]rod [on the crossmember bracket] on top of the frame to add support to the bolt. I removed the 1/2-inch rusty bolts on my Venture trailer and replaced them with Grade-5 5/8-inch-diameter bolts. I hammered down the tangs and added U-bolts to keep them down.