DIESEL DOCTOR: Diesel fuel changes during the year
HI, MY name is Paul Smallacombe, Lubricants Technical Manager at Viva Energy representing the Shell Rimula
Heavy Duty Diesel engine oil brand.
I have worked as a technical expert with Shell lubricants for 14 years, both in the field making recommendations for the right oils for transport, mining and industrial customers, as well as working on our technical helpdesk taking calls from small and large companies wanting advice on the right lubricants to use in their machinery.
I currently sit on the Australian Transport Association Industry Technical Committee.
This year I will be writing a column with Big Rigs to help answer your questions around engine oils and fuels, which
is designed to keep you informed, and help you get to your destination as quickly, safely and cheaply as possible.
This week we look at greases, the differences between various greases, and why more than one grease should be
used to keep you on the road.
Different types of grease
There are many different types of greases available and it can get confusing for truck operators. In general terms there are three main components in a grease formulation.
The base oil, the thickener, and the additives.
The base oil is the largest component of a grease and usually it does most of the actual lubrication work.
The thickener, as the name says, may be any sort of component that helps the grease form a solid or semi-fluid
Thickeners may include ingredients such as lithium or calcium and will give the grease more enhanced properties
depending on the type of thickener.
For example, a Calcium thickener provides good resistance to water, but makes the grease more difficult to pump.
Lastly, the grease contains additives, which further enhance the properties of the base
oil and thickener.
So what grease should you consider?
There are two key activities that a grease has to perform on a truck, and they have very different requirements. The first is a grease for wheel bearings.
Wheel bearing grease must be able to withstand high levels of heat (from the bearing), and be able to handle exposure to the elements (rain, dirt, etc) to protect the wheel bearing.
So the ideal properties for a wheel bearing grease are resistance to heat, a medium level of viscosity (not too think so that it impedes the bearings and causes overheating, and not too thin so that it drips off under heat).
The other essential grease for a truck is a fifth wheel grease.
This requires very different properties to a wheel bearing
It must be able to stay in place with the trailer on top of it and not ooze out, and it must be able to withstand
shocks as the trailer bumps up and down.
We recommend that truck operators do not use the same grease on both wheel bearings and the 5th wheel as they
require very different properties to protect the equipment.
Using the wrong grease in a wheel bearing can lead to fire (if over packed) or can affect the bearing performance.
Using the wrong grease in a 5th wheel may result in very limited or no protection as the load forces the grease out.
Resulting on metal on metal wear.
As always, our technical team would be happy to help you further with your grease requirements.
If you have any questions you want answered, send a note in to Big Rigs at firstname.lastname@example.org