Checking axle alignment
I was wanting to check the alignment of the axles on my trailer and was thinking of tying a weight to a string and hanging it from the kingpin then marking that spot on the ground. From there measure...
Forum Discussion
BoonHauler wrote:RCMAN46 wrote:rhagfo wrote:dbbls wrote:
As long as both axles are parallel it doesn't matter about the distance to the king pin. If it is off a little all it will do is make the trailer follow a little to one side. Not enough to matter. It is not uncommon to see big rigs tracking sideways.
Not true! If the trailer is going down the road cocked to one side you will have tire scrub and if enough could be clearance issues in narrow spaces.
Not only that but the trailer will go to one side then snap back to center.
This can result in a little sway.
Most of us have seen some small trucks and vans that do this.
dbbls is kind of right and kind of wrong.
The lead axle MUST be set exactly perpendicular to the long axis of the trailer.
If the axle is perpendicular to the frame the distance from each spring hanger to the king pin will be the same. That is what that measurement checks. So he is dead wrong.
Once the lead axle has been set the trailing axle/s centerlines must be held equal on both sides.
Uneven side to side loading on the axles can also cause the Dog-Tracking
Here's a few links Trailer Design Considerations
and Trailer Resource Library
I set my axles to a 1/16th of an inch tolerance.
The spring hangers have to be welded in the correct location on the frame first and foremost. If they are not then the trailer probably will not tow well and will probably result in excessive tire wear.
Lippert has benn known to mess this up as a friend of mine found out.
