Willys Jeep - Rancho Leaf Spring Axle Wrap

[@timmcooper294]

As a guy who has held on stubbornly to leaf springs for the past 35+years of wheeling, in both spring under and spring over form, you would probably see an improvement by running two thick "overload" leaves at the bottom of the pack, run the stock thin factory style leaves for the majority of the pack, but with a slightly thicker (like the Ranchos you have) main leaf for strength. The two bottom leaves should have less arch than the rest of the pack so that they are barely touching when the rig is loaded up with gear. This type setup has allowed me to smoke tires on the rocks for years, even sprung over, (traction bars are for amateurs) I love how the crude technology of leaf springs is so tunable and really works amazingly well if set up right. Take my advice with a grain of salt (your results may vary) but I've checked out all the crafty stuff you've built, and you have my utmost respect !! Keep on tuning, testing, and get those rear corners done up like your front fenders !!!

[@jpetrowich]

My next step is to go with a set of 10 leaf stock replacements and take leafs out if necessary. I have seen Stan and other locker- stockers wheel this obstacle on stock replacement springs without issue. One difference is that I have more horsepower. Why do you say traction bars are for amateurs? I have had many people who I trust recommend one. The concept seems good to me so long as the bar is long enough for minimal reprocussion on spring travel. With my setup, I just don’t seem to have the room for one.

[@timmcooper294]

@@jpetrowich I really like the old way of making leaf springs (lots of thin leaves that can flex more before fatigue sets in) I think your issue involves not only the wrap resistance of the pack, but also its resonant frequency, and last, but certainly not least, your re-located shock mounts. The other Jeeps still have the shocks mounted in the stock location, which does offer a certain amount of resistance to the wind / unwind oscillations. As for calling traction bars "amateur" For over 30 years that has been the standard default everyone and his uncle preaches. Very few people in the off road world put the effort into really understanding how leaf springs work, and take that easy way out. Traction bars bring a whole slew of issues, one of which you are aware is packaging. The other is less obvious, instant center. Part of the crude magic of leaf springs is that , well set up, your effective instant center is way up front, creating a "neutral" , stable feeling chassis under torque loads when climbing, with no "jacking" affect. Torque arms put your instant center right at the front of the arm, and if the arm isn't really long, can make the rig less stable by the jacking effect. Don't get me wrong, there is a time and a place for torque arms, but I feel it's a way over - prescribed band-aid in the vast majority of cases.

[@billydouglas5966]

Rory Irish uses a traction bar on his wrecker with great results. It is interesting to see older videos before the install vs. after. That truck works hard, pulling a trailer off-road at times with no wheel hop. Packaging and clearance may be issues, but if it works with no bad side effects I’m happy to join the ranks of amateur.

[@carlharris4265]

Get it! Gettit gettit gettit! Whew, that was intense.

[@redeyecafegarage7484]

Great video! That is pretty wild to see in slo mo from that angle.

[@joetheadapterguy]

Jeff i've got the 9 leaf crown springs (no safety wrap) on the rear of my 5 and it twists up quite a bit. even before i swapped the v6 in the f134 would twist the pinion up what in low without really putting any load on it.

[@EngiTrek]

Pretty interesting. Would you consider keeping the softer springs and go with some sort of traction bar? Modifying the leaves to be any stiffer would result in decreased performance in other areas such as wheel travel and ride quality. This is assuming it’s an actual problem that you want to fix.

[@jpetrowich]

Adding a traction bar would be difficult because I don’t have much real estate to work with underneath. My frame is 29” wide and I have an exhaust crossover thst only can go across in certain places. I don’t really want to use a traction bar because I’m trying to learn and demonstrate spring dynamics. I know, I could just put a bar in and be done with it, but I don’t learn anything then.

[@АйбалаБалбаев]

Потрясающе!!!

[@angieurrutia8813]

Amazing!

[@michaeljames9671]

There's a big assumption here. We need a similar video showing stock springs or similar.

[@alkatib100]

Nice video. The question is would the original springs do the same?

[@jpetrowich]

I have wheeled with other flat fenders who run stock, or stock replacement springs, (9 leaf). They do a much better job on the obstacle; smoother, slower. That being said, they are running 4 cylinder motors. kzbin.info/www/bejne/mZPCd3SwjquBbJI Click on the above link and go to the 14:50 mark. You can see my dynamics. I have tried it slow, fast, left, right, center. It always looks like the above video or worse. Next, I am going to HD stock replacements. (10 leaf, .2 thick)

[@alkatib100]

@@jpetrowich thank you for your reply. I am looking forward to see you on the trail soon. I am in Taho area

[@studiovladosproduction5936]

WOW! Video

[@brennanmetcalf]

I would try a slightly longer spring perch first. Ideally, if it matched the loaded arch of the spring that would be best. Something about 6" long should make a noticeable difference without getting in the way of flex. Beyond that, in order to increase the torque capacity of a leaf pack, you need more leaves, but the thickness of those leaves need to decrease in order to maintain the same spring rate. You can have a low spring rate AND more torque capacity this way. When the leaves get thinner, we also need to make sure to add a military wrap 2nd or even 3rd leaf to keep things alive in the off road environment. As we decrease spring rate, we also need to add free arch to maintain the right loaded arch ( lift ).

[@timmcooper294]

Good points here. I like lots of thin leaves, the way leaf springs used to be made. My recommendation assumed thin leaves for the bulk of the pack, and "military wrap" as well. The two "thick leaves" at the bottom of the pack would be arched to be close to touching the rest of the pack at kerb height / weight. This type setup has worked so well for me in many of my rigs over the last 3 decades running Rubicon, Johnson Valley, Fordyce, Moab, many trails in Alaska and Canada with tires from 32-40 inches. There are so many ways to do things "right" (or wrong!) , and Jeff is a smart guy. I like his analytical approach to things, and I'm looking forward to what he comes up with !

[@jpetrowich]

Thx guys, I certainly get the multiple thin leaf thing. I’m basically just trying off the shelf stuff to learn the good and the bad thru actual demonstration. I know guys who run these ranchos and also bounce all over the place so this is for their benefit as well as my curiousity. Anyone thinking about buying this style spring, (thicker and fewer) should at least consider this video. Last year I ran a set of crown replacements (9 leaf). I wore them out in less than one season but they did perform decent at first. I’ve seen the 4 cylinder guys wheel the crowns for 2-3 years without a problem. There is no doubt in my mind that my horsepower plays into it. As I said earlier, I have a set of 97-335s which are 10 leaf .2 thick each. I want to give them a shot. The purpose of the video is FYI and also to spur conversation like we are having. My personal goal is to compare the economical spring options available and learn. Thx 4 the comments. I appreciate them.

[@billydouglas5966]

Jeff, Do the 97-335’s have a military wrap?

[@jpetrowich]

@@billydouglas5966 yeppers. I’ll text you a pic

[@TrokaRC]

Cool stuff, I do rc.

[@slateslavens]

damn!