Let’s face it, leaf sprung suspensions have been around for a while…a long while, in fact. We are talking back to medieval times on wagons and carts according to our research. That means leaf springs are as old as the Black Death… as old as or older than windmills, eyeglasses, suits of armor, and really old stuff like that. Sounds fancy, huh? Well, it is, or can be when done correctly. That’s because while leaf springs may be old-school, they are one old-school part that still works; they can be built using old tricks to work really well. In fact, old does not have to be bad, and using some old-school leaf spring building ideas can make custom leaf springs better than those that are widely available for Jeeps.
Leaf springs are without doubt a very important part of on- and off-road technology. They do many jobs—locating the axle, holding the Jeep up, and helping smooth those jarring holes, rocks, and curbs. Leaf springs are a real life example of the KISS rule: Keep it simple stupid. We love that rule. While many Jeeps and trucks out there are wearing leaf springs not all flat boingers are created equal. There are several characteristics of leaf springs that make them work well for what we use them for. Many thin leaves made of high quality spring steel, tapered ends, military wraps, Teflon non-friction pads, and so on all help leaf springs work well. That work could be flexing out on the trail, supporting lots of weight in the back of a loaded Jeep, or helping a go-fast Jeep blast over the bumps. Of course, adding all these features to every leaf spring manufactured today is prohibitively expensive, but with a little more investment in some custom springs you can get leaf packs that work better than the el cheapo alternatives.
We recently got a chance to check out some high-end leaf springs on our retro ’56 CJ-5 in the form of some custom built springs from Deaver Spring of Santa Ana, California. These springs should bring our old-school CJ-5 into supple riding, bump hugging, rock flexing, old-school go-fast Jeep.
Ordering these springs is a bit more complicated than going on line clicking “buy now” and entering shipping and payment information. You need to get an accurate weight on your Jeep (front and rear weights are nice) so that the springs can be built for your specific vehicle. You will also need all the dimensions of your current springs, or you may need to mail Deaver one of your springs to duplicate. Pictures of the shackle-angles and vehicle stance at ride height help Deaver figure out spring length and arch. Once Deaver has all the information necessary, they will build your springs from high-quality spring steel. This is like your cooked-to-order steak rather than that old pre-made burger or pizza under the heat lamp.
Step By Step
The leaf springs on our restomod ’56 CJ-5, Project Ground-Up, were originally designed as a front replacement for spring-over suspensions on YJs or Jeeps with YJ leaf springs. Our Jeep does not have a spring-over, and it never will as long as we own it. These springs have performed pretty well over the past year or so both on- and off-road, but after we bent one in Moab last year, we started to wonder if we could hone our CJ-5’s somewhat dull suspension into a razor-sharp knife.
Here is the bent main leaf we mentioned. We are pretty sure that it is the result of rolling back into the slickrock on a steep climb (for a CJ-5) on the Mashed Potato trail during Easter Jeep Safari. Subsequent wheeling trips, including one where we may or may not have had to grab Reverse after nearly tipping the old Willys during a photo shoot (hey, we wheel the thing hard!), did not help the leaf get straighter. It seems it won’t heal itself no matter how long we hold out. Poo.
Replacing the one leaf pack with the bent main leaf would have been a simple solution to our problem, but heck, this is not a magazine about simply fixing Jeeps, it’s about making them better. Our solution was to toss a set of custom-built Deaver springs at our old CJ to see if we could get it to work even better off road. Here you can see one of the 10-leaf Deaver packs and one of the old five-leaf packs that we are dropping.
Snail wrap, military wrap, whatever you wanna call having the second leaf in a leaf pack wrapped fully or partially around a spring’s eye, does a few things. For us, it’s gonna help prevent bending. That’s good for us. Military wraps can also help prevent axlewrap that usually is associated with spring-over suspensions. It’s probably not a problem for us, but still a bonus.
All four of our springs are identical and a spring-under suspension installation of the new leaf packs is pretty simple. We supported the frame with some big jackstands. Next, pull the tires and loosen the bolts retaining the leaf springs at the spring eyes and then attack the U-bolts. Once they are off, you can support the axle with smaller jackstands. Now pull the old springs and install the new springs. We were able to swap rear springs without pulling the shocks, but you may have to pull the shocks, maybe even the driveshafts, and sometimes brake lines, too.
It’s important to grease he polyurethane bushings and bushing sleeves, even if you have greaseable bolts like we do. There are two sleeves with YJ springs because generally YJ shackle bolts are smaller than the main-eye bolts. The thinner wall sleeves go in the full-wrap ends, while thicker wall sleeves go in the half-wrapped ends and bolt into the shackles.
Deaver specially builds based on your Jeep’s weight, so you will need a front and rear weight before ordering. The specific dimensions of the spring are also very important. In most cases, Deaver wants you to send one of your springs in to them to use as a template. Shackle angle at ride height and vehicle stance at ride height are important as well. We wanted a touch more lift to help deal with weight and flex while keeping the tires out of the body.
In the bumps the Deaver springs seem to absorb jarring hits much better than the aftermarket YJ springs we were using before. If anything, the shocks and four-cylinder engine are what are keeping us from going even faster in the dirt. Hmm? New shocks and a V-8? Well, maybe at least new shocks.
Here you can see the benefit of the spring clamps Deaver uses that allow the 10 leaves to fan out when the axle is drooped. This increases flex and keeps tires on the ground when off-road. Tires on the ground get more traction than those hanging out in the breeze
The multiple leaves, tapered ends of the leaves, and non-friction pads all help the springs flex and ride smoothly on- and off-road.
Here you can see the flex that the Deavers allow. Awesome! This thing has always flexed way better than a stock early CJ-5 with narrow, short springs and a flexible frame. Our frame does not flex much and our YJ springs are longer and wider than early CJ-5 springs, but this is still an upgrade. The good news is we can hit slow flexy trails with our new springs with gusto.
Beefing Our Dana 30 Front Axle
Given our plans to beat on our ’56 CJ-5 even harder now that we have nice supple springs, we decided it would be prudent to beef up the inner knuckle-Cs where we have seen an axle like this bend before. To do this, we cut up some cardboard to make a template for some gussets. Once those gussets were in place, we cut and bent a piece of 1⁄4-inch flat bar to the top of the gussets and the knuckle. Once finished, we hit everything with some gloss black spray paint. Hopefully we won’t bend the axletubes or housing. You can also see that we spot-welded the caps on the front axle shaft U-joints, as we noticed that some were spinning after the installation of a locker (“Front or Rear,” Sept ’13).