Big-truck sales in Canada fell 8.7% last month, with three of the five classes recording losses, WardsAuto data shows.

Class 8 sales fell 14.3% as most manufacturers suffered declines, including International, down 28.8%. Falloffs at both Freightliner and Western Star sank Daimler sales 28.5% below year-ago.

Volvo Truck deliveries were up 6.3%, on a 24.7% gain at its namesake brand, the biggest jump among Class 8 marques.

Total medium-duty sales climbed 5.9%, as strong growth in Classes 6 and 7 offset drops in the smaller-truck groups.

Class 7’s 36.1% increase, the biggest among all groups in August, was a result of gains at nearly every manufacturer. International posted the biggest spike, up 92.6%, while PACCAR sales climbed 42.9% on positive results for both the Kenworth and Peterbilt brands.

Ford’s 42.2% drop was the group’s largest, albeit on small volume, while Hino Class 7 sales fell 26.9% from like-2012.

In Class 6, a 45.0% increase in volume-leader International’s deliveries was the sole gain recorded among truck manufacturers last month. The Illinois-based company’s 125 units offset losses at nearly every other OEM and buoyed the group’s sales to a 27.7% gain from year-ago.

Losses among most brands and manufacturers brought Class 5 deliveries down 7.6% vs. year-ago. No.1-seller Ford’s 19.4% reduction was the biggest factor in the group’s slump, though low-volume PACCAR recorded the largest percentage decline.

Ford lost about six points of market share in Class 5, with Chrysler the beneficiary. Its share rose to 28.5% from 23.4% year-ago, thanks to a 12.8% increase in sales.

Ford also was the culprit in Class 4’s 21.1% drop, with sales sliding 29.0% to 70 units.

Isuzu’s domestically built trucks posted the biggest increase in Class 4, up more than 100%, but on just 11 units sold.

Year-to-date, Canadian medium- and heavy-duty truck volume was down 9.7% through August from like-2012.