Flat plates welded to trailer axle and spring mount points.
Flat plates welded to trailer axle and spring mount points.
(OP)
Good evening everyone
I bought a trailer fitted with electric brakes the other day and while underneath it I noticed one of the flat plates welded to the axle and spring mount points had cracked.
I pointed this out to the manufacturer and he stated that the primary role of the plate was to hold the axle in place during assembly and that the 'U' bolts prevented the axle from rotating when the brakes are applied.
I accepted this explanation until I was told by another manufacturer the exact opposite regarding the plates.That is, that the primary role of the plate was to stop the axle from rotating.
My experience tells me that the 'U' bolts are there to hold the axle in place and to prevent it from rotating.
Does anyone have the definitive answer?
Regards Bob
I bought a trailer fitted with electric brakes the other day and while underneath it I noticed one of the flat plates welded to the axle and spring mount points had cracked.
I pointed this out to the manufacturer and he stated that the primary role of the plate was to hold the axle in place during assembly and that the 'U' bolts prevented the axle from rotating when the brakes are applied.
I accepted this explanation until I was told by another manufacturer the exact opposite regarding the plates.That is, that the primary role of the plate was to stop the axle from rotating.
My experience tells me that the 'U' bolts are there to hold the axle in place and to prevent it from rotating.
Does anyone have the definitive answer?
Regards Bob





RE: Flat plates welded to trailer axle and spring mount points.
Can you post a picture? for easier if we can see your problem.
desertfox
RE: Flat plates welded to trailer axle and spring mount points.
Bob
RE: Flat plates welded to trailer axle and spring mount points.
When the brakes are applied, the front of the spring dips and the rear of the spring catches to prevent further dipping. This attempts to rotate the axle, but since the plate is bolted to the axle, the friction of the U-bolts against the axle tube resists rotation. When you have a plate welded to the axle tube, it is usually done so with gussets under the plate and conforming to the tube radius. When brakes are applied to this configuration, the welds are subject to radial shear to prevent rotation. The intent here is to prevent rotation of the plate around the axle, to lessen the bending in the spring. The spring works best when load is applied in the same direction on both shackles. When braking, the load on the shackles is not the same, in fact one is usually up and one is usually down.
Either system can assist in the trailer assembly as the plate defines "top dead center" of the axle tube.
RE: Flat plates welded to trailer axle and spring mount points.
RE: Flat plates welded to trailer axle and spring mount points.
RE: Flat plates welded to trailer axle and spring mount points.
Since the tube is perpendicular to the plate, there's not as much chance for cracks to migrate into the tube...usually isolated to the plate.
I got the impression this was a used trailer. If new, I agree...don't accept with cracked plate.....even used, have them fix it.
RE: Flat plates welded to trailer axle and spring mount points.
Yes, it is a second hand trailer and yes they will now be welding the plate and redoing the other side as well.
Have a safe and enjoyable Christmas.
Regards Bob