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  • Diesel Truck Sled Pulling Information - Burnin' Rubber

Diesel Truck Sled Pulling Information - Burnin' Rubber

Sled-Pulling 101

Matthew R. Amero
May 1, 2006
Photographers: Matthew R. Amero
Photo 2/2   |   diesel Truck Sled Pulling sled Pull
So, you want to learn how to start sled-pulling? Think you're up to the task? Keep in mind you'll be hooking your truck up to a weight transfer sled that weighs around 55,000 pounds-enough weight to pack the dirt track surface underneath it high into the Rockwell hardness scale! But, don't let that minor detail scare you off. Mechanical failures of your truck's drivetrain can be significantly reduced (or eliminated), if you prepare and pilot your vehicle according to a few simple guidelines. We hope to dispel some of the misconceptions concerning sled-pulling, as well as provide some helpful hints that will give you a competitive advantage right out of the box. Now that we've got your attention, here's what you need to do.
First and foremost, carefully read the rulebook pertaining to the sanctioning body you will be pulling with. Members of the Diesel Hot Rod Association (DHRA) are mailed a printed copy of the rules as part of their membership package, and an electronic version of the 2006 rulebook is also available on the website, www.dhra online.com. If after reading the rules you discover that the whole scenario seems daunting, come on down to the track anyway. The best pullers out there all had to start somewhere, and you can put money on the fact that they were in the stands watching other people pull back when they were in your shoes.
Depending on the class you decide to participate in, the level of required preparation can vary greatly. Your best bet is to start out in a "stock" category class. These classes allow ordinary 4x4 diesel pickups and travel trailer haulers to get out there and take a swing at pulling the sled.
In most stock categories, the engine should be the least of your worries, as long as it is in good mechanical condition and doesn't exhibit any obvious signs of premature wear. Pulling the sled is hard work, so you'd be best advised to perform preventative maintenance and top off all fluids beforehand. Depending on the age, type, and condition of your transmission there are a few things to remember. Manual transmissions themselves are usually built strong enough for pulling-the same can't be said for the clutches that drive them. Pulling can outright destroy a brand-new factory clutch, if you are not careful. With a large number of aftermarket clutches rated for pulling available on the market, this is one area manual transmission owners should invest some money. Automatic transmission owners have fluid coupling inside the torque converter as a built-in fusible link that helps prevent shock-loading the drivetrain. Selecting a proper transmission gear is easy if you do some quick research by asking other pullers with trucks similar in build to yours. Gear selection is directly related to the amount of power you are putting to the ground. Since you are just starting out, select a low gear (numerically higher than 1.00:1) and take it easy. All transfer cases should be in Low-range, if so equipped. If you grab a high gear and are displeased with the truck's performance, most rules specify that if you release the throttle before the 75-foot line, you will be permitted a second attempt at the discretion of the track officials.
Since pulling is all about putting the power to the dirt, many people believe that an aggressive tire is a competitive advantage. For stock-type classes, this is not necessarily true. Aggressive tires require more power to turn, and in a stock class you're already limited in that regard. Along the lines of drivetrain failure, there is no better way to shock-load your drivetrain than with a set of tall or grabby tires on hard-packed dirt. All-terrain tires offer ample traction on the majority of pulling tracks and the asphalt you drive on everyday. Traction bars or other devices that prevent axlewrap are also recommended.
Back at the business end of the truck, your hitch is also a big factor deciding your success or failure. Running the hitch too high places a lot of leverage on the truck and will greatly affect an underpowered engine-there is room for tuning here. Keep the hitch height and general construction within the guidelines of the rules, and build it from thick, solid steel stronger than you think you'll need. It is not uncommon to see hitches made from 3/4-inch-thick steel. Factory receiver hitches can be used, but the commonly available tongues are often not constructed with sled-pulling loads in mind. Weight transfer sleds use large hooks to attach to the pulling vehicles, so your hitch should be able to accept a hook that is at least 3 inches thick. There are other guidelines in every sanctioning body's rulebook that you must follow. Be sure that you and your vehicle are in compliance before attending an event.
Now that the truck is prepared, plan the trip so that you pull up to the fairgrounds at least an hour before the event is scheduled to start. Find the registration booth and head there first-once you sign the waiver and hand over the necessary fees, now would be a good time to ask when and where the driver's meeting is. After you leave the booth, you can swing your future event-winning vehicle into the pits and tie up loose ends while waiting for the driver's meeting announcement. Attendance at the driver's meeting is mandatory. At some events, drivers will be disqualified if they do not attend the meeting.
In order to expedite the process of allowing all the trucks a chance to go down the track, you must follow this one easy rule: Stay with your vehicle at all times. If your truck is unattended and blocking the right of way, it will be removed and could disqualify you from competition. We realize that you want to watch the action on the track and help your fellow pullers in the pits, but there are thousands of fans in the stands and many other competitors counting on you to keep the action flowing.
When you near the point in the lineup where you are second or third in line, observe carefully the process of getting onto and off the scales and ready to hook. Don't bother hanging weight or adding ballast; you are a rookie learning how to pull and probably have enough traction as it is. After you have passed tech inspection and weighed in, no changes can be made to the truck-that includes adding or removing weight. It is also requested that you do not borrow equipment from other pullers in your class. Swapping equipment from one truck to the next in the same class is too time-consuming and is frowned upon by your fellow competitors and track officials.
Now that you are on-deck, follow the instructions of the flaggers and track officials. They will inform you when it is safe for you to slowly pull out onto the track surface and begin backing toward the sled. After the truck is hooked to the sled, you will be instructed to pull slightly forward to tighten the chain and stop. Watch the flaggers carefully and wait for both of them to signal with a green flag before proceeding. Manual transmission drivers should not roll backward while raising engine rpm with the clutch disengaged. Automatic transmission drivers don't have to do much more than put it in Drive and slam the pedal to the metal. This is the culmination of all your preparation and instruction, but try to keep the nerves icy cold and remember what you've learned. Don't ride the clutch for more than a second or two unless you have an aftermarket clutch-just rev up the engine, dump the clutch, and floor it. Now that you're rolling, as you go down the track, you will feel the truck working harder than it ever has before, but resist the temptation to stare at your gauges. The short-lived high temperatures seen on your coolant temperature or EGT gauges are not likely to cause damage if your engine is in good working order. Keep your eyes centered on the track and watch for the flagger at the end of the track as you start to slow down. Once the flagger has signaled you to stop, ease off the throttle and apply the brakes once you have rolled to a stop. Do not hit the brakes while going down the track; the weight transfer sled has a lot of momentum and will strike the back of your truck. Now that you've just completed your first hook, it's time to unleash from the sled-slowly back up to the sled following the instructions of the track staff and wait to be unhooked. Once unhooked, drive forward slowly off the track amidst the cheering crowd and head into the pits. At this point, you have been indoctrinated into sled-pulling.
Once you are in the pits, find a spot to park that is out of the way and idle the engine for at least 5 minutes to allow the temperatures to normalize before shutting it down. After shutting the truck down, you can find out your exact distance and then watch the other pullers. Many drivers are hooked (pun intended) on the first pass and really enjoy it, while others may get discouraged from a poor final distance. All of the usual words of encouragement apply here: Don't let your first pull get you down, because there's always going to be another pull for you to attend.
If you are now ready to try a hook, check out the DHRA Diesel Power Sled-Pulling Series schedule at DHRAonline.com. Also, on June 24-25, 2006, Indianapolis Raceway Park will once again host a DHRA National event.
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