Truck modifications may have contributed to freak accident

Modifications or poor maintenance may have contributed to the freak accident in which a driver was killed by a flying truck part, a coroner heard yesterday.

Pukekohe plasterer Eddie Tavinor died instantly when a hefty part of the oncoming truck's driveshaft smashed through his Mazda ute's windscreen, decapitating him, in November 2000.

The father of three, who was in his early 30s, was driving north on Auckland's Southern Motorway on a busy Monday when, around 10.30am near Penrose, the Mitsubishi container truck's driveshaft broke off, sending the yoke of its front universal joint bouncing across the median barrier.

The solid-metal yoke is about 350mm long and weighs around 5kg.

Mr Tavinor was driving within the speed limit and the truck was travelling about 100km/h.

Crown lawyer Ross Burns said it appeared the immediate cause of the driveshaft's failure was the collapse of a needle-roller bearing housed in the yoke.

Likely causes or contributory factors leading to this were:

* Modification of the six-wheel truck - to lower the height of large containers - putting driveshaft angles outside the manufacturer's specifications and placing unnecessary strain on the drive train.

* Inadequate lubrication of the bearing, leaving accumulated debris inside where it could cause excessive wear.

* Faulty reinstallation of the bearing during servicing.

* Reuse of existing bearing retaining straps.

* Failure to notice wear and tear during servicing.

The truck, leased to Container Swinglift Services, was three years old and had covered just over 200,000km at the time of the crash. It was serviced by Roadlife Trucks, which is now owned by Mitsubishi Motors.

Senior Constable Stuart Kearns, a North Shore police crash analyst, said the truck's driveshaft had been off in the workshop at least four times, the last time 11 days before the crash for a gearbox repair job.

Removal of the driveshaft meant removing the bearing straps from the front universal joint.

He said the makers of the Dana/Spicer driveshaft warned against reuse of the metal retaining straps or saddles that hold the bearing in place.

They also warned against the use of "Loctite" thread-locking glue on each strap's two bolts.

The straps were designed to be stretched down tightly on the bearing using a torque wrench to obtain the exact bolt tension.

Mr Kearns quoted from his interview with the main mechanic for the gearbox job, Aaron White, who will give evidence before coroner Dr Murray Jamieson later in the inquest.

The policeman said Mr White stated that he had never read a manual for a Dana/Spicer driveshaft. Mr White said he reused the existing straps, applied Loctite and did not employ a torque wrench.

He was unaware that use of a torque wrench was stipulated and thought the straps should be replaced only if they were deformed, broken or had elongated holes.

Mr Kearns said a police search of Roadlife Trucks in April last year yielded no Dana/Spicer manual.

But Mitsubishi lawyer Les Taylor said later evidence would show that Roadlife did have one before and after the search.

Mr Kearns said truck driveshaft failures occurred daily, often at low speed, and their seriousness depended on many factors. Long driveshafts could be particularly dangerous if they failed.

"If the front end ... is to fail, it can dig into the road and catapult the truck in a manner like an athletic pole-vaulter.

"I attended one such incident several months after this where a bread van's driveshaft had come off at the front and had catapulted it to roll end on end."

Mr Kearns said evidence emerged in the police inquiry of truck-modification work not being officially certified.

The Land Transport Safety Authority had been told, but it had not advised the police of what action it had taken since.

"I cautioned the LTSA that if a crash occurred with any of those vehicles they could be accountable."

Mr Kearns rejected the suggestion, from authority legal adviser Tony Beach, that auditing truck-modifying companies was outside the LTSA's jurisdiction.

The inquest continues today.