Overslung and Underslung of Trailer Axles

                                       

Before purchasing mechanical suspension and air suspension which contain  trailer axles, you need to ensure which type do you want, overslung or underslung?

 Underslung have the trailer leaf springs assembled under the trailer axles and overslung have the trailer leaf springs above the axle. This won't make any difference for their strength but the overslung can avoid bump while riding on the rough road because of the gap between the axle and the chassis.