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Bryan Irons photos
Fallen Leaf
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Bryan Irons photos
Fallen Leaf
1 Plastic sliders are often used between leafs in the pack to reduce the friction associated between them and alleviate some noise. Not all leafs have them, and they are not always the same. This one had enough of our shenanigans and was jumping ship.
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Fallen Leaf
2 A few different styles of leaf retaining plates can be seen. Higher end packs (like our Rubicon Express units here) use this U-bolt design to keep the leaves aligned. Strap styles work as well but do not allow freedom of movement and are seldom reusable. The disturbing portion of this picture is the bare metal showing. This means a few of our leaves have been trying to escape along with the sliders. This is not a “fix it later” find.
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Fallen Leaf
3 With the rig securely on jack stands and the suspension at full droop, the old U-bolts need to be removed. Try unbolting them, but this is usually a futile attempt. We managed to unbolt one side; the other required a more forceful tactic.
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Fallen Leaf
4 If you have to cut the U-bolts, make sure the differential is held in location and you are well protected as you cut the U-bolt in the centre of its arc. They’re under a lot of tension and will make a “bang.” We like using a plasma cutter to keep our hands clear, but a cutting disc works as well. Safety first or you may never count to 10 with pants on again.
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Bryan Irons photos
Fallen Leaf
5 Centering pins are used to keep everything in alignment. These are what fell out of our leaf pack. Years of abuse and vibration caused the worn areas before they finally snapped in protest. This is the root cause of our dog tracking and unwanted axle movement. It is not the duty of the centering pins to keep the axle in place, but just to align everything. The U-bolts are what keeps it all firmly held in place.
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Fallen Leaf
6 Now that we are making the turn for home, it’s time to take note of wear patterns for reassembly. Keep the leaves in the same order and orientation as before is imperative to the longevity of the pack. Here you can see the distinctive wear pattern between these two. Also note the tapered ends of the leaves to spread the contact area out. No sliders are used on these overload leaves. Normally a drilled hole for locating is present with sliders.
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Fallen Leaf
7 We picked up some new leaf spring sliders from Trail Gear to replace the seven broken/missing ones we found/lost. The shipping cost more than the parts themselves, so buy a handful and keep some spares.
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Fallen Leaf
8 Installation of the sliders is easy when the packs are apart; just push them through the locating hole.
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Fallen Leaf
9 The high levels of friction between the leaves when used in off-road situations can pop them out or shear the mounts off occasionally. We have seen them glued into place as well, but this doesn’t seem to help much in our experience.
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Fallen Leaf
10 The next step in the process is installing new 3/8-in fine thread centering pins. We scored ours from Kelowna Truckworks along with our new U-bolts and hardware.
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Fallen Leaf
11 We have degree shims built into our leaf pack. We prefer steel shims that have the centering bolt going all the way through them. Most centering pins are grade three or five only and do not required massive amounts of torque to hold the packs together.
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Fallen Leaf
12 Don’t forget to trim the extra bolt length off before continuing. We like a little Loctite on them for good measure.
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Fallen Leaf
13 We don’t recommend re-using U-bolts because the threads are often damaged and nuts deformed. The torque applied to them actually stretches the threads slightly and locks them in place. Be wary of trailer U-bolts and chrome plated overseas units. We have had those fail in the past.
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Fallen Leaf
14 For more clamping force, we stepped up from ½-in U-bolts to 9/16-in. They come in many sizes and diameters; match yours for your application. Our Dana 44 required a 2.75-in diameter and overall length of 6-in. Truckworks was even kind enough to give us the recommended 150 ft-lb torque spec with fresh hardware.
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Fallen Leaf
15 With everything in place, time to start torqueing the U-bolts evenly. Our U-bolt sliders made installation a little more difficult, but not impossible. Using an impact to flog them down must be done with caution, apply the torque evenly.
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Fallen Leaf
16 Even though we are talking “steel”, cold flow (when metals squish and stretch) will happen. Take a break before final torqueing and spray a little lube between the leaves to allow smoother movement. We don’t like using grease as it attracts dust and grime and turns it to a grinding paste. Pro-Long’ SPL100 infiltrates the metal without collecting any grunge.
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Fallen Leaf
17 Back to the task at hand, 150 ft-lb for us and rotate around until no more movement is detected.
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Fallen Leaf
18 For future ease of spotting “shiny” parts, give everything a coat of paint. This is Canada after-all. Also, trim your U-bolts off so you don’t get caught up on the trail.
Story & photos by Bryan Irons
In recent years, the lowly leaf spring has been quartered off and left for dead with the horse drawn carriage they came in on. It’s antiquated technology, and every trail hero in a coil sprung rig will tell you so. We’re not telling you to scrap the leaf design currently adorning your ride; in fact, many of the OEM’s are still belching out new vehicles with the trusty leaf spring attached. We’re here to tell you that when set up properly, they work rather well for something that started life smoothing out country roads in horse drawn carriages. And like any other suspension design out there, some preventative maintenance is still required despite their durability.
Our typical PM program involves us hunkering down under the rig with a flashlight, groaning like an old ship in a bad storm and looking for shiny things. Shiny parts mean metal-on-metal contact and that something has moved. Our trail donkey “Stinky Jeep” normally hauls down the trail with ease and can be blasted down the highway with one finger on the wheel, but on a recent outing something was wrong, way wrong.
If you’ve ever cared to watch one of “man’s best friend” (K9’s here kids, not wobbly pops) walk down the road, you’ll notice that their rear legs don’t always follow in line with their front. This is fine for a dog, but no good for a vehicle on the road and garners the moniker “Dog Tracking”. We had such an issue and were fighting our way up a snowy trail trying to keep the wheels between the ditches. A quick inspection showed shiny parts under the rig on the rear leaf springs and bare metal on the wheel wells. It was time to go home on the back of the trailer. This is no time to chance driving on public roads.
Driving the Jeep onto the trailer was the real eye opener as the front tires were evenly placed on the deck. The rear tires, however, were shifted over to the passenger side by almost 20 cm. The lowly and depressing drive home gave us time dry our tears over a missed off-road excursion.
Once back home, we skidded the rig off the trailer like a corpse off a gurney and scuttled it into the shop where its future would be determined. With wheels off and rig securely raised, our autopsy began. A polished rear differential cover, severely rubbed fender openings and a few quick measurements showed that both leaf mounts had been moving around. Check out what we found, how we fixed it, and what we did to keep it from happening again.