MECHTRONIK
Member
The recent Toyota vehicle recall and admission by Toyota president Akio Toyoda who said that Toyota has, for the past few years, been expanding its business rapidly. Quite frankly, I fear the pace of which we have grown may have been too quick," I would like to point out here that Toyota's priority has traditionally been the following: first - safety, second - quality, third - volume. These priorities became confused."
This got me wondering about a problem that has been apparent to me for many years of off road dump truck runaways.
A lot of the off road dump trucks sold in the world in the last 40 or more years’ run an automatic transmission with hydraulic disk brakes. The problem is they have also fitted a spring applied, hydraulic or air off park brake.
While this park brake system works fine when properly fitted and adjusted there is no failsafe system were this to fail and fail they do with disastrous consequences. There have been thousands of truck runaway incidents around the world and a lot of death and destruction.
This brake relies on constant maintenance to hold the truck when not attended Problems I have personally encountered on new and old units are pad wear out from faulty automatic adjusters and from driving units with the brake applied. Disk mounting bolts shearing off. Calliper actuator seizing from lack of grease. Calliper mounting bolts coming loose.
Mining companies and contractors around the world have been getting around this problem by parking in spoon drains and installing wheel chocks. No one trusts a parked truck!!!
I think it is time dump truck manufactures have another look at the incident reports that have been flooding in over the years and have the guts like Akio Toyoda and admit there is a problem before someone else gets killed.
MECHTRONIK does not design dump trucks; we check them over before you buy. Yet I can’t help wondering why a parking pawl is not fitted as a failsafe.
A parking pawl is a device fitted to a vehicals automatic transmission in order for it to lock up the transmission. The parking pawl locks the transmission's output shaft to the transmission casing by engaging a pawl (a pin) that engages in a notched wheel on the shaft, stopping it (and thus the driven wheels) from rotating.
Ok maybe the transmission manufactures are not fitting this to their larger transmissions to avoid damadge in case of accidential engagement but that doesn’t mean this well known saftey device should be left out of the truck design completely as there are many other parking pawl systems available to truck manufactures.
MECHTRONIK
This got me wondering about a problem that has been apparent to me for many years of off road dump truck runaways.
A lot of the off road dump trucks sold in the world in the last 40 or more years’ run an automatic transmission with hydraulic disk brakes. The problem is they have also fitted a spring applied, hydraulic or air off park brake.
While this park brake system works fine when properly fitted and adjusted there is no failsafe system were this to fail and fail they do with disastrous consequences. There have been thousands of truck runaway incidents around the world and a lot of death and destruction.
This brake relies on constant maintenance to hold the truck when not attended Problems I have personally encountered on new and old units are pad wear out from faulty automatic adjusters and from driving units with the brake applied. Disk mounting bolts shearing off. Calliper actuator seizing from lack of grease. Calliper mounting bolts coming loose.
Mining companies and contractors around the world have been getting around this problem by parking in spoon drains and installing wheel chocks. No one trusts a parked truck!!!
I think it is time dump truck manufactures have another look at the incident reports that have been flooding in over the years and have the guts like Akio Toyoda and admit there is a problem before someone else gets killed.
MECHTRONIK does not design dump trucks; we check them over before you buy. Yet I can’t help wondering why a parking pawl is not fitted as a failsafe.
A parking pawl is a device fitted to a vehicals automatic transmission in order for it to lock up the transmission. The parking pawl locks the transmission's output shaft to the transmission casing by engaging a pawl (a pin) that engages in a notched wheel on the shaft, stopping it (and thus the driven wheels) from rotating.
Ok maybe the transmission manufactures are not fitting this to their larger transmissions to avoid damadge in case of accidential engagement but that doesn’t mean this well known saftey device should be left out of the truck design completely as there are many other parking pawl systems available to truck manufactures.
MECHTRONIK