A tractor trailer alignment can save you up to $3500 per year

A tractor trailer alignment can save you up to .25 miles per gallon. That is right. You can raise your mpg from 6 to 6.25 just by re-aligning a trailer that is out of alignment.

Most companies do not think of alignments as parts of their maintenance program. Usually you only worry about semi-trailer alignment after a driver or two has complained about dog tracking, or your trailer is shedding tires left and right. Did you realize that a miss-aligned trailer could be costing you and extra 500-700 gallons of diesel fuel per year per trailer? 500 gallons at $2.19 per gallon is $1095.00. 700 gallons at 4.95/gal is $3465.oo per trailer. How many trailer are in your fleet?

A trailer alignment is a fairly straight forward procedure that you can perform in your own shop. All you need is the proper tools. If you do not have a shop, you can bring your trailer to any qualified repair shop. You should expect to pay 2-2.5 hours of labor for a semi-trailer alignment plus some incidentals. Make sure you express your desire to be notified of any other necessary repairs before additional work is started. Depending on your maintenance program and age of your trailer, you may need some additional parts to perform the alignment. Lower radius rods are often frozen and bushings wear out which will require a re-bush prior to performing the alignment.

A semi-trailer alignment is performed by gathering information on two unique measurements. The thrust angle and the scrub angle. The semi-trailer industry specification is ±.1°. This is equivalant to ± 1/8 " difference in the measurement of the king pin to the axle track thrust angle or measurement "A" to measurement "B". Tire manufacturers are little more lenient. They allow for a trust angle of ±.2°. Therefore, our tractor trailer alignment must have a thrust angle of less than ±.1° or 1/8".

Any axles behind the front axle are part of the scrub angle measurement. The trailer industry standard is 1/16". All scrub angle measurements are taken from the front axle regardless of how many axles you have remaining. Large fleets and multi-axle trailers are good reasons why a trammel arm could be a good tool to have to perform a semi-trailer alignment.

The 3 things you'll need for a tractor trailer alignment

You will need to accomplish 3 tasks for a tractor trailer alignment. Click the links below to go to each procedure.

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