GM’s G80 Locking Differential Gets The Traction Job Done
9 hours ago
by Bruce W. Smith
The dirt access road along the section of new highway being built on the Mississippi Gulf Coast was slippery and rutted from all the equipment passing over its surface. The red clay base, drenched by heavy rains the day before, was like potter’s clay only worse.
I was riding along with one of the surveyors headed back to resume his work shooting grades when his Chevy Silverado’s right front suddenly took a nosedive. The truck came to an abrupt halt.
It didn’t take much of an inspection to see a temporary culvert running beneath the road had collapsed as his diesel 4×4 rolled over it and now the pickup was ingloriously parked in a two-foot-deep quagmire that no amount of four-wheel-drive or deep-lugged mud tires was going to overcome alone.
Fortunately my driving partner wasn’t that worried; the big winch mounted on the front of his pickup was there for that very reason—the unexpected.
Like true pros, we ran out the cable to the last few wraps, slipped a nylon strap around a big stump, connected cable to strap, and proceeded to yard three tons of mud-bound 4×4 to firmer ground.
Over the decades I’ve learned a winch is a lot more useful than just a tool used for getting my own vehicle moving. More often than not I find it invaluable for helping others get their vehicles out of trouble, or its mechanical muscle called upon around the job site.
But having the right winch combo is the key to it all. Choose wrong and it’s wasted money.
Before you begin to physically shop for a winch it’s important to understand how winches are rated in pulling power. The pulling power of a winch, stated as “line pull,” is the maximum load the winch can exert before it stalls.
Line pull is based on which layer of wrapped cable the load is exerted. But winches are only marketed by their maximum pulling power—a figure derived pulling from the innermost wrap on the drum.
A winch drum is actually another gear in the overall scheme of winching power: As more cable winds onto the drum, the larger the working diameter gets, which decreases the winch’s load-pulling capacity.
As a general rule of thumb, the second layer of cable above the drum cuts the winch’s rated pulling power by about 10-percent. Succeeding layers reduce effective pulling power anywhere from 5 to 15 percent. (See “Winch drum cable pulling power illo.”)
So when maximum pulling power from a winch is needed, run the cable out until it’s down to the bottom layer while leaving at least five wraps of cable around the drum.
Another factor to consider is line speed in and out. Those speeds, under full load, can vary from 3 feet-per-minute (ft/min) to 8fpm depending on model and brand.
No-load speeds can range from 16 ft/min to 75 ft/min. What you choose depends on how fast you need to winch something or retrieve the winch rope or cable.
Last on things to consider is the size of the motor. If the other factors are similar, favor the one with the biggest motor.
For example, a 6-hp electric motor will take less amperage for the weight being pulled and will run cooler longer than a 4.5hp. Integrated circuitry to prevent over-heating is also a great feature.
That brings up another point: Which is better, wire cable or synthetic winch rope? Synthetic winch rope has the advantages of being a lot lighter and much easier to work with than the old-fashioned aircraft cable.
But beware synthetic winch rope is a lot more susceptible to being cut when pulled across or against sharp edges such as rocks and frame parts.
It has to be kept clean, too; mud, sand, or other debris on job sites
It has to be kept clean, too; mud, sand, or other debris on job sites has the same abrasive effect when that rope is put under a load, and the individual strands compress against each other, as if you were putting a knife or file to the them. (The same applies to nylon winch and tree-saver straps.)
So unless you are the type that comes home after every outing and washes and cleans anything that got dirty, stick with good old winch cable and let the posers use the winch rope.
ELECTRIC OR HYDRAULIC
Flip the coin here. Electric winches are less expensive, much easier to install, and provide some margin of pulling capacity when the engine isn’t running.
However, that power is dependent on a strong battery. Electric winches also generate a lot of heat in operation, so long, tough pulls are hard on the motor and solenoids.
Hydraulic winches, which typically operate off the vehicle’s power steering pump, are unequaled for the ability to pull a load for as long as needed – or as long as the hydraulic pump is operating.
While an electric winch’s pulling time is determined by the electrical components ability to withstand heat build-up and the condition of the battery, the hydraulic winch’s performance is entirely dependent on the operation and strength of the hydraulic pump. The two-speed versions usually pull in low gear and retrieve line in high gear.
Mile Marker and Warn Industries offer both types of winches, and both company’s products can be found in a wide range of capacities on many heavy-duty pickups and military/tactical vehicles around the globe.
“In heavy duty, or demanding work situations, it is important to consider the construction and duty-cycle of the product before you make your purchase,” advises Mile Marker’sTim Hasse.
“For example, our winches feature galvanized roller fairleads, steel cables, and heavy powder-coat finishes for a lifetime of corrosion free performance.
“In addition our patented Mile Marker hydraulic winch has a submersible design, stainless steel hardware, and provides 100% Continuous Duty Cycle., which translates to non-stop recovery until the job is finished,” says Hasse.
“Electric winches, by design, remain intermittent tools,” says Hasse, “and must be carefully monitored when used for extended duration pulls and pulls of heavier loads, as their DC motors pull high amperage from the 12 volt DC Battery system. This can lead to a dangerous heat level at the motor, and without a proper cool down period, can lead to winch failure, and even fire hazards.”
So look carefully at the most difficult task the winch is going to be used for and select the right size and type winch to meet that heavy duty pickup demand.
Electric or hydraulic, figuring out where and how the winch is going to be mounted also plays a role in your purchase decision.
Low-profile winches are great for pickups and SUVs that have small grilles or ones used in hot climates where good airflow to the engine is vital.
Portable winches mounted to hitch drawbars/shanks are nice because they allow the winch to be used on any vehicle or ATV/UTV with a standard 2”receiver. But they are really heavy and may require a second person to help lug it from vehicle to vehicle. They also require a quick-disconnect system for battery power.
Mounting kits that keep the winch above the factory bumper are good because they 1) keep the winch out of the muck; 2) they can be easily swapped to another vehicle of like make/model; 3) they keep the package cost down because you don’t have to buy a dedicated winch bumper.
Such winch mounts attach to the frame and bumper, so there’s no worry of failure. Almost all have provisions for extra tow hooks and auxiliary light mounts, which are great around job sites.
My winch-mounting preference for a pickups used in the demanding conditions of a work environment is a dedicated heavy-duty winch bumper.
The best ones are built from heavy steel and have provisions for the winch, turn signals, lights, tow hooks and jacking points. Custom winch bumpers are expensive—but well worth the investment.
From self-recovery and recovering other vehicles, to removing downed trees or winching a piece of equipment onto a trailer, a winch is a must-have for any contractor’s vehicle.
The key is investing in the right winch for the task.
What I base a winch selection on for pickups and SUVs is multiplying the vehicle’s “Gross Vehicle Weight Rating” (GVWR) and adding another 25-percent.
GVWR is the weight of the truck and its maximum payload capacity as noted on the vehicle’s door tag – or in the specifications pages of the owner’s manual, and adding another 25-percent.
For example, a 2010 Ford F250 Crew Cab 4×4 diesel has a GVWR of 10,000 pounds. Multiplying 10X1.25 = 12,500. So, a winch with at least 12,000-pounds-pulling capacity would work fine for most contractor’s situations.
And going to a hydraulic winch might be a good consideration instead of electric if you are going to be using it a lot for long pulls.
Overkill? Not if you think about the physics involved in winch recovery work.
When a vehicle gets stuck in mud, sand, or aggregate, the tires dig down. That leaves a step the tires must get up and over before the truck can move again. So the winch has to literally have the power to both lift and pull a vehicle to free it.
Hence my criteria in using the vehicle’s fully loaded weight as the basis for choosing the right winch. That way you should always have pulling power in reserve.
If you rarely take your heavy-duty pickup off-pavement with a load in the bed, you can squeak by with a little less winch. But I wouldn’t go any smaller than 10,000-pounds capacity if your pickup is a ¾-ton 4×4 or larger.