Several times a month, vehicles come in with major damage caused by trying to tow too much weight. Information on towing is plentiful, but often inaccurate and incomplete from a repair standpoint. Surprisingly, most trucks we see will NOT tow their rated capacity without problems.
Information on towing capacity is sometimes slanted by those who benefit from your choice
Gettinghonestadviceisimportantandmanytimesdifficulttoobtain.Thisisespeciallytruewhenbuyingatrucktotowalargeboatortraveltrailer.Folksusuallybelieveanytruckwillreliablytowanyamountitcanphysicallypull.Unfortunately,thisisnotthecase.Whenatruckisusedtotowmoreweightthanitshould,damageisbeingdone.Thecomponentalmostneverfailsimmediately,butthelifemaybedrasticallyshortened.Oncethedamageoccurs,failureisinevitable.Thisholdstrue,regardlessofhowfewtimesthevehicleisoverloaded. Over loading a vehicle one time can cause damage and shorten its life.
"I don’t tow that often," makes no difference to overloaded components
Becauseavehiclewillphysicallypullagivenweight,doesnotmeanitcan beusedto. Theengine of a truck isnevertheweaklinkinthechain.Almostanyenginewillpullthefullratedcapacityofthetruck.Thetransmission,brakesandreardifferentialarewhere problems occur.Ratedtowingcapacityisapopularsalespointwithtrucks.Manufacturers tendtoover-ratetheirvehiclesandreliabilitysuffersasaresult.
A more realistic guide, from a standpoint of reliability, is to tow no more than two-thirds of the rated capacity with any truck. For example, a truck rated at 7,500 pounds towing capacity, will reliably tow 5,000 pounds. Buying a vehicle, rated at least 33% over the weight to be towed, results in far fewer repair bills.
Four-wheel drive does NOT add to the towing capacity of a vehicle
Most four-wheel drive vehicles use the same transmission, differential and brakes as their two-wheel drive counterparts. A half-ton four-wheel drive will tow no more weight than a half ton two-wheel drive. Four-wheel drive increases traction on slippery surfaces, but does not increase the amount that may be towed. Rather than four-wheel drive, a three-quarter or one-ton truck is a much more reliable choice.
Larger tires do NOT increase the towing capacity of a vehicle
Using an oversize tire may actually decrease the weight a vehicle will reliably tow. Larger diameter tires increase the effective rear axle ratio, and increase the loading on drive-line components. Taller tires also significantly increase the loading on brakes. The distance from the road surface to the center of the wheel may be thought of as a lever, working against the brakes. The longer the lever created by the tire, the greater the load on the brakes.
A "towing package" adds very little to the actual capacity of a vehicle
The phrase "towing package" is often little more than an advertising slogan. A towing package may merely have a transmission cooler and possibly an extra leaf in the rear springs. Adding a cooler to a transmission, that is too light to pull the weight it has to pull, will not increase longevity.
Selecting the proper gear for towing
Towing a light amount (under 2,000 pounds) requires little extra input from the driver. When towing heavier amounts, it may be beneficial to shift out of overdrive. This is particularly true if the vehicle appears to be straining or downshifting a lot. If the vehicle is equipped with a "Tow/Haul" button, it should be in Tow position. This allows the power control module to change the shift strategy applied to the transmission.
Shifting the transmission into first gear or manual low will help to protect it,especiallyonaslipperysurface.Anexampleiswhenpullingaboatupaboatlanding.Ifthedrivewheelsareallowedtoslip,thetransmissionmayshiftintohighergears. Shifting while spinning can causedamage to occur.Shiftingthetransmissionintomanual-lowappliesadditionalclutchesandhelpspreventup-shiftingifthewheelsstarttospin.
Whentowing alsoconsiderthefullweightbeingtowed. Theweightoftheboat,trailerortravel-trailer is part of the total weight.Thereis also theweightofthethingscarriedinthetrailerorboat.Passengersaddtotheloadbeingpulledandshouldbeconsidered.Besuretoaddforwaterandwastetanksanditemslikeclothing,food,toys,etc.