Commercial trailer backlogs reached 101,244 units in April. While backlogs grew during the month, net orders posted a 30 percent decline from the previous month, according to ACT Research.

ACT also noted that industry backlog is 141 percent above levels at this time last year, while build was nearly double the rates witnessed in April 2010.

"The 30 percent decline in April net orders follows extremely strong industry performance in March. Additionally, the industry's normal order pattern actually calls for a strong first quarter followed by a mid-year lull", said Frank Maly, director CV Transportation Analysis and Research with ACT Research. "April net orders were the start of that seasonally anticipated lull."