Already in May 1938, after cracks had been discovered in the conventional armour of the M36 vehicles, the ministry of defence had asked DAF whether their type, using untried welding techniques, could also be prone to cracking; in the summer of 1938 the commander of the "1e Eskadron Pantserwagens" while testing the demonstrator vehicle had also expressed his concerns on this matter. Despite the warnings by Addink, Van Doorne pretended that he was unconcerned. Nevertheless the May 1939 contract had contained a warranty clause, instructing DAF to weld all connections tension-free and making DAF liable for all defects of this nature. Late March 1940 during cleaning it was discovered that on three of the six vehicles the welds of the machine gun mounts were cracking. One vehicle was sent to DAF that rewelded the crack and reinforced the glacis by riveting a steel plate behind it. Soon however, it transpired that next to the reinforcing plate a new crack had appeared. In April the number of cars showing cracks had risen to five and on some of these the welds between the glacis and bottom plates were starting to crack also. According to DAF the defects had been caused by attaching the mounts after the vehicles had been largely finished. The "Comissie Pantserautomobielen" concluded that, as war was imminent, DAF should be allowed to quickly repair the cracks by rewelding and fitting reinforcement plates but that ultimately the armour plates had to be completely replaced.