Ron Gratz wrote:
JBarca wrote:
OTOH If after you had adjusted the hitch as described above;
And you add extra weight to the truck bed behind the truck rear axle which is a large enough weight and or far enough behind the axle to lower the back of the truck, this can change the hitch head angle relationship to where it was originally adjusted to and add a level of tension to the WD bars. How much tension rise in the WD bar depends on how much the hitch head angle changed.
If the downward force exerted on the A-frame by the WD bars is increased, the load on the TT's axles will increase.
Since the weight of the trailer has not changed, and since the trailer axles now are carrying more load, the vertical load on the receiver must decrease by an amount equal to the load increase on the trailer axles.
Hi Ron,
I agree with you "if" there was weight added to the trailer A frame. That was not what I was saying or thinking. There is no weight change on the A frame. My thought was;
- The back of the truck was lowered by adding enough weight to truck bed (and the farthest back from center of the rear axle increases the moment)
- The added weight will compress the truck suspension to change the hitch head angle.
- The hitch head angle will tilt back the head (not a lot, but still be towards the TT)
- This head angle change will increase the WD bar tension for that point in time the weight was added
- The back of the truck will rise to create equilibrium once again but at a different lower vertical location.
- If the WD bar is sized larger, the drop effect will be less. (This is the only thing I can think of "why" they are saying this)
There will need to be enough weight change in the truck bed to practically affect this. A light suspension truck will have more affected then a heavier truck for the same amount of weight added.
Example 400# of oak firewood sitting right at the tail gate area. On a 1/2 ton truck that will cause a lot of truck drop ~ 2" - 3". On a 1 ton truck not so much but still movement ~ 1/2 to 1".
Ron Gratz wrote:
JBarca wrote:
That is the only way I can figure (right now at least) why they feel you need to upsize the WD bars. If there are other ways, please point them out.
I have no idea why they feel you need to upsize the WD bars. Perhaps they'll change this recommendation just as they have changed their recommendations for amount of front axle load restoration.
Ron
I agree, I am scratching my head on why they are trying to create a 1 size fits all recommendation. And they carry the same recommendation from a 600# WD bar to a 1,700# WD bar.
