From The book "44: In combat from Normandy to the Ardennes" by Charles Whiting - Chapter 4 "Breakout". In a paragraph suggesting that Allied equipment(Sherman, 6Lb A/T, Etc. Etc.) was generally inferior to German. I quote the following
	Quote:
	
	
		| The British three-ton Leyland truck also fell short of requirements, by the end of the Normandy campaign, 1,500 of them were in the workshops. | 
	
 I regret that I only add to the question - I have no idea which vehicles or what the problem was