8 minute read
Tow Manager
Tow MaNager Proper Use and Maintenance of Dollies
By Brian J Riker
Brian J. Riker is a third-generation towman, with 25 years of experience in the ditch as a tow operator, and president of Fleet Compliance Solutions. He specializes in helping navigate the complex world of federal and state transportation regulatory compliance. He can be reached at brian.riker@fleetcompliancesolutions.net In certain situations the dolly is a preferred method for towing.
Wheel dollies are an overlooked piece of equipment on wreckers until they are needed. Most towers do not use their dollies often making their upkeep and inspection a low priority which can lead to a failure at a critical time resulting in serious damage, injury or even death. As with all other tools and equipment on your truck, dollies must be inspected daily and serviced as required to ensure they are safe to use when needed.
As you conduct your daily walk around or pre-trip inspection you must inspect your dollies to make sure they are properly secured in their mounts, none of the components can come loose from the truck, the tires do not show signs of excessive wear and are properly inflated. You should also check the wheel bearing for excessive play by holding the dolly frame securely with one hand while attempting to wiggle the tire and wheel assembly side to side with the other hand. If you can feel any movement or a “popping” sensation your dollies should be serviced by a qualified professional as this indicates excessive play in the wheel bearing assembly that will lead to a catastrophic failure while in tow.
When used properly dollies are a safe and efficient method of towing vehicles that would otherwise require a carrier or be damaged due to low ground clearance. With the increased popularity of lowered vehicles dollies are a must have tool for dealing with these heavily modified vehicles – often the better choice than using a carrier.
It is important to read the owner’s manual for your exact make and model of dolly as they are not all the same regardless of their similar appearance and function. There are significant differences in the maintenance procedures, speed and weight ratings as well as the steps to load and unload different models and especially among different manufacturers.
There are many things to consider when deciding to deploy dollies as an alternate to using a carrier. Since there are many differences between available products my suggestions contained in this article are for general guidance only, always follow the instructions for your specific make and model of dolly.
Your first consideration should be the weight rating of your dolly as compared to the weight of the vehicle you wish to ◀
tow, keeping in mind which end of the vehicle is heavier and what level of access you have to the vehicle based on its position. Most light duty dollies have a weight rating between 3,040 and 4,280 pounds with the maximum capacity of the tires being the primary determining factor. Always make sure the end of the vehicle you intend to support with dolly wheels will not exceed the rating of your equipment. Whenever possible you should lift the heavy end of the vehicle in tow with your wrecker.
Is the vehicle in a position that will allow adequate access to install the dollies and is the vehicle on a hard surface? In general dollies are only intended for use on-road, it is not advisable to use dollies off-road due to the uneven stress that will be placed on them.
Can you install the dolly axles without placing yourself into harms way? This is especially important on highways where you must avoid stepping into the traffic lane to place an axle under a vehicle. Keep in mind the space required to use the lift bar to raise the dollies into transport position and where you would land should you slip and fall while raising the dollies.
Once the decision to deploy dollies has been made you need to make sure the vehicle will not move unexpectedly. The best way to accomplish this is to secure one end to your wheel lift before beginning to install the dollies. Depending on the dolly manufacturer it is recommended that once secured to the wheel lift the vehicle be placed in neutral and the parking brake released to allow the vehicle’s wheels to rotate as the dollies are raised and reduce stress on the dolly assembly while in tow.
As you remove your dollies from their mounts on the wrecker or carrier give them a quick inspection for missing, loose, cracked or damaged parts. Pay special attention to the locking and release mechanisms, tires and axle tubes.
When you place the cross bars under the vehicle to be lifted adjust them so that they just protrude past the sidewall of the tires on the axle you are lifting. Keeping these tight reduces the flex (bow) of the dolly cross bar and improves the overall strength of the dolly assembly as well as reduces your overall width making driving safer.
Next you would install the dolly cross bars into the dolly frame as per the operator’s manual, being sure to set any safety locking mechanism in place before attempting to lift the dolly wheel into place. This is a good time to triple check the locking and lifting mechanisms for damage.
It is critical to install and use the swing-over or pry bar as recommended in the operator’s manual. Always hold the bar firmly with both hands and be sure you have solid footing before attempting to lift the dollies into transport position. A slip in this critical step can cause the bar to release rapidly and result in serious injury to your body, arms or face possibly even causing you to fall into traffic.
Once the dollies are in transport or lifted position make sure the transport locks are engaged as per the operator’s manual. Some dollies have secondary locks that must be engaged, others have a specific position to install the wheel strap to work as an extra safety measure to prevent unintentional disengagement of the dolly axles.
To strap or not to strap? This shouldn’t even be a question yet it is often the subject of debate among towers of all experience levels. The simple answer is yes, straps are a must. Every dolly manufacturer requires them in their operator’s manual and the Federal Motor Carrier Safety
Regulations also require them as part of load securement.
The regulations do not specify exactly how the vehicle must be secured, only that it must be secured with adequate tie downs installed either over the tires or to points on the vehicle and designed for such use by the manufacturer.
Given that all dolly manufacturers provide specific instructions on the use of straps they are the only appropriate method to secure the dollied end of the vehicle into the dolly assembly. When selecting straps always use the design and type recommended by your dolly manufacturer.
Here are some basic guidelines for selecting straps, hooks and ratchets for use with your dollies. Pick a working load limit equal to or greater than the maximum load rating of your dollies. Look for straps with built-in edge protection to reduce wear and extend the working life of the straps. Always stay with the hook design ◀
from the original equipment manufacturer to avoid stressing tiedown points. Your dollies will have specific attachment points for the straps that should always be used. It is not advised to use other points on the dolly assembly as they may not be rated for the stresses applied by the straps. Never modify the design of your dollies without consent of the manufacturer.
Long distance or short haul only? The answer to this question depends upon the make and model of your dolly assembly. Among the two major manufacturers Collins shows an unlimited distance limit provided that the speed never exceeds 60 MPH while In The Ditch recommends only short distances at or below 50 MPH. With all dolly assemblies never exceed the tire speed and load ratings as they are the weakest link of the assembly. Always make sure the tires are properly inflated. Tire pressure is critical to load capacity. Keep in mind a tire is considered flat when it is just 20 PSI below the recommended inflation pressure.
With all dollies you must avoid high speed potholes and slow to a crawl over railroad tracks to avoid damaging or dislodging the dollies.
As with all equipment proper maintenance is a must. The most critical, and often overlooked, component on dollies is the wheel bearing assembly. Bearing freeplay should be checked daily and torque must be checked at least monthly, more often with more frequent usage. Depending on design the bearings may need to be disassembled to grease. Most newer bearing assemblies are equipped with some type of grease fitting system to allow an operator to easily pump grease into the bearing without disassembly. There are many aftermarket upgrades available such as the Bearing Buddy which replaces the dust cap with a grease fitting.
Cleaning your dolly assembly often will extend its life by reducing corrosion and abrasion caused by road grime. It will also allow for easier inspection helping you discover defects before they become critical. Pay attention to the springs and locking assemblies and always apply recommended lubrication after cleaning as per the operator’s manual.
In conclusion, dollies are a very useful tool to have available. When used properly they can safely support many towing operations beyond simply lifting a drive axle off the ground to prevent driveline damage. With some additional equipment dollies can even transport vehicles with missing wheels or damaged suspension.
