Limited private car testing is taking place at MOT centres in Northern Ireland.
An inspection of all vehicle lifts in the centres detected signs of cracking in 48 of 55.
Drivers across Northern Ireland due to take the road worthiness test suffered disruption.
The Infrastructure Department said anyone who had a test rescheduled would be refunded half of the MOT fee.
It added: “All DVA test centres are providing MOT tests today, with limited private car testing at a number of centres.
“There is a rolling programme of inspection, repair and re-inspection to all lifts being used in test centres with lanes becoming operational as this process progresses.”
Belfast, Cookstown and Newbuildings lifts are fully operational, with two of three lifts operating in Coleraine Test Centre and three out four now operating in Craigavon Test Centre.
The remaining test centres will be inspected and any necessary repairs carried out over the coming days, the department said.
Due to a fault identified with some of the vehicle lifts, it was necessary to take the precautionary measure to suspend the use of vehicle lifts until they had been inspected and, where necessary, repaired, it added.
This meant that some test lanes had to be closed at short notice and appointments cancelled.
In addition to its ongoing regular monitoring programme, the Driver and Vehicle Agency (DVA) has also introduced additional inspection processes to ensure the safety of its staff and customers.
The department added: “While repairs are being completed the number of tests taking place on cars and light vehicles is reduced, but tests are taking place.”
There were 1,891 vehicle tests conducted on Thursday across test centres.
DUP assembly member Michelle McIlveen said: “It is worrying that so many lifts have been identified as faulty and it brings into question the maintenance and inspection process.”
She is expected to raise the matter with infrastructure minister Nichola Mallon.
Ms McIlveen added: “Those will be issues which pre-date the minister’s period in office but hopefully she will be able to bring clarity as to why the faults were not identified earlier.”