The Transport Agency is warning that tougher enforcement from now on will mean other garages, certifiers and transport operators will get caught.
The lawyer brought in to overhaul the agency, Steve Haszard, said the agency has cleared its 850 crisis cases and stabilised itself.
Two more garages were suspended on Friday over warrant of fitness safety problems.
Mr Haszard said these latest suspensions demonstrated how the agency meant to operate from now on.
"What you are starting to see now is what you are going to see moving forward," Mr Haszard said.
"When our frontline officers are coming across conduct that is clearly unsatisfactory and there's a safety component to it, we're just taking swift action now."
An independent report earlier this week found systemic failures within the organisation. The agency admitted in October that it has not been carrying out proper checks on companies that certify vehicles.
Rebuilding would be difficult as the agency was a "long, long way away" from being up to scratch, Mr Haszard said.
It has so far recruited just a third of 30 new roles to monitor and enforce road safety rules, after these operations were stripped of people over the course of several years of restructuring that followed the creation of the agency in 2008.
They also needed a much better, joined-together data system to, for instance, track poor operators, Mr Haszard said.
The clampdown since October has resulted in more than 170 revocations, suspensions and warnings to garages and certifiers and transport operators, putting almost 30,000 trucks and cars under a cloud.
Sixty-four truck, bus and passenger vehicle companies have been given notices they will be suspended or have their licences revoked entirely, while 10 have already been revoked and five suspended.
Twenty-two service providers - most of them WOF inspectors or garages - have been suspended, five revoked and 11 face suspension or revocation.
The shift, from crisis to rebuild, meant the agency would lift a slowdown it brought in last October on approving garages to issue warrants.
The industry has told RNZ that businesses wanting to get approval to issue WOFs or Certificates of Fitness are facing waits of 100 days or so.
One garage owner told RNZ he would not have bought the business if he had known about an October directive from the NZTA board to its management to "identify options and make recommendations on how to stop or slow down the approval (and re-certification) of (new) organisations or individuals who can issue licences, certificates, warrants and other authorisations".
Slowdown action was in place for a few weeks and now the agency would speed up approvals to faster than in previous years, using a new decision-making group that meets twice a week, Mr Haszard said.