Third Major Blue Ox Casualty

pigman1 wrote:

2.The area of the Silverado under the Blue ox bolt heads and nuts was too little for the loads imposed by those bolts and nuts. It thinned out and this is what loosened the bolts. The thinning was verified by a micrometer. A large heavy washer installed under the bolt heads and nuts would have spread the load to "PROBABLY" (my conclusion) not cause the frame to thin and the bolts to loosen. HOWEVER Blue Ox did not furnish such washers nor did their instructions call for them.


5. ......snip...... The outline of the bolt head and the nuts in the toad frame where the thinning occurs says overload to me, and probably to most every other engineer.


7. I definitely agree that the metal quality in pivots, bolt and pin bearing surfaces and the knuckle is less than desirable. This is what is causing the excess looseness and slop that begins to overload other areas of the hitch bar and base plate and causes them to begin to fail. Regardless, poor engineering design and perhaps inadequate testing is also a major contributor to these problems. .......