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Leaf springs

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Matt S View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Matt S Quote  Post ReplyReply Direct Link To This Post Topic: Leaf springs
    Posted: 27 Nov. 2022 at 9:51pm
Hello,
I'm looking for some thoughts on leaf springs for a CJ2A that I want to be able to do the Rubicon trail.

This is going on a Jeep that is basically a frame with a broken rear axle, rusted transmission, and a locked up F-head.

I have a Dana 30/44 combo for it.  I plan to install a 4-speed and a VW diesel.

The current leaf springs are rusted and appear flattened.  I've started to contact a leaf spring manufacturer to build a custom set of springs.  Something that is flexible with a small bit of lift.

I think I need 33" or 34" tires and maybe a 2"-3" lift.  I'm looking for thoughts on what tire size I'd need for the Rubicon trail and the cooresponding lift.  I had thought of the Holbrook springs but they have closed their doors.  I understand from the threads I've searched that I'm looking for a skinny tire but I'm looking for some ideas from those who have more experience.

Thanks!
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Rick G View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Rick G Quote  Post ReplyReply Direct Link To This Post Posted: 30 Nov. 2022 at 12:59am
For what it's worth, I am running 34" Narrow Super Swampers and a mix of production and custom spring sets located on the original perch locations.  I have run the Rubicon three times with this setup.  If you are going to run 33" or larger tires, you definitely need a couple inches of lift in your springs.  I would not go more than 3" because it really alters your center of gravity with 33"-34" tires and things feel really tippy.  

Springs like these are only available as custom builds, as you are aware.  I spoke with Alcan a while back and they are extremely knowledgeable and capable of building the perfect spring for this setup (here's a link to a thread on them that someone else started:  Alcan Leaf Springs - The CJ2A Page Forums).  They are a little expensive, but probably worth it.  I have not used any of their springs, but I will probably have them build me a set eventually.  Right now, I'm running a mix of old Black Diamond springs (which were way too stiff) and some custom springs that I had built locally.  The Black Diamond springs had 3" of lift and 5 leafs, but offered NO FLEX WHATSOEVER!  I removed a couple of leafs and that helped, but reliability suffered, and I broke several springs (not on the Rubicon, however).  

My personal preference for a spring pack is multiple leafs (7-9) that are thin, just like the original sets, but with a couple inches of lift, and military wrapped ends.  If you don't mind relocating your spring perches (which I didn't want to do) you have lots more options.  Several guys here are running stock CJ5 springs with lots of success.  Perhaps they will chime in with their thoughts and experience.  Based upon my experience (with mostly bad springs, and some mediocre ones), I firmly believe your ability to navigate obstacles with success (and ease) is directly proportional to the correct spring setup.  Other things come into play, obviously (e.g. lockers, tires, and gearing), but I would spend the money on a great spring setup.  

My recommendations for the Rubicon in a "locker-stocker" flatfender are:  33-34" tires, 2-3" lift, locked axles, and a crawl ratio of at least 65:1.  You can make it thru the Rubicon in a stock flatfender, but you will have your work cut out for you.

Hope this helps.
Rick
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1951 CJ3a #451-GB1-24268   “Newt”

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Post Options Post Options   Thanks (0) Thanks(0)   Quote smfulle Quote  Post ReplyReply Direct Link To This Post Posted: 30 Nov. 2022 at 11:18am
Hi Matt,
Opinions on springs are not quite as religious as oil or tires, but close.
I have run the Rubicon twice with 29 inch 7.00 x 16 NDT tires and stock springs without any major issues. The most helpful upgrades on the Rubicon and other rock bashing trails, in my opinion, is locking differentials and lower transfer case gears. More belly clearance is nice, but a few husky buddies can usually push  you off of whatever you're high centered on.
Springs - I am a big proponent of stock or stock replacement springs in a flat fender used for trails and rock crawling. In fact, I buy the cheapest stock replacement springs I can find for several reasons. If you are driving your flattie on the rocks, the springs take a beating and eventually get bent and need replacement. I think of them like tires that will need changing out every few seasons or so. The expensive ones get bent just the same as the cheap ones so why pay extra? Ride comfort, these jeeps are never going to be smooth riding, but a stiff spring will rattle the fillings out of your teeth. One of the ways that spring builders make springs lift higher is to stiffen them up. A stiff spring is uncomfortable on the trail and can be tricky to deal with on uneven surfaces where flex is helpful. And worse case can bounce your tires off the ground and you on your head. 
If one were going to use their jeep as a truck, or a tractor, then a stiff, heavy spring set would be better, but on the trails, softer, but not floppy, is pretty nice.
Lots of guys on here have longer and more wheeling experience than me, and all my experience is with one jeep and what I have observed on jeeps I wheel with so take all that into consideration because as always, your mileage may vary.

PS: for reference here's a video of our group on the trail a few years ago. Mine's the rusty light blue one. Rick who wrote the previous post is the shiny light blue one.



Stan
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Matt S View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Matt S Quote  Post ReplyReply Direct Link To This Post Posted: 30 Nov. 2022 at 11:24pm
I was thinking of tires like you are running (34" skinny super swampers) and I've also contacted Alcan spring.  I'm just not sure of the amount of lift for the tires.  I do like not being top heavy but I also am not a huge fan of cutting the body.

I appreciate your recommended formula.  I'm planning on locked Dana 30/44 and a 4 speed for a lower crawl ratio.

Great insights and thank you for the response.
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Matt S View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Matt S Quote  Post ReplyReply Direct Link To This Post Posted: 30 Nov. 2022 at 11:31pm
Stan - Im still reading your build thread.  That's amazing.  I've been watching your videos for quite a while and it was what really pushed me to get my Jeeps in the same time zone as me to get them going.

I appreciate the fact that the springs get bent and need replacement.  That's great insight.  I wasn't looking for ride comfort.  I do recall the only time I drove the one Jeep it felt like we were going to do a summersault when we hit bumps.

I'm looking for something flexible.  I did see another option of using 4 rear springs and raising the body to fit the tires.  I think my cost estimate per spring was about 3x for a custom set of springs that are flexible from Alcan.

Great items to think about.  I really haven't decided which way to go.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote jeepsterjim Quote  Post ReplyReply Direct Link To This Post Posted: 01 Dec. 2022 at 12:10am

Speak with Brennan on springs and builds.

http://https://brennans-garage.com/
Jim
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Matt S View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Matt S Quote  Post ReplyReply Direct Link To This Post Posted: 02 Dec. 2022 at 10:14pm
I like that website.

I think I've been talking with him on another site.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote MochaMike Quote  Post ReplyReply Direct Link To This Post Posted: 31 Mar. 2023 at 4:43pm
Subscribed (for my build).

I'm trying to decide on cheap stock springs or after market lift springs.
I currently wheel a 62 IH Scout.  I had 2.5" lift YJ Springs  (BDS) which I really liked.
But the weight of the heavy Scout wore them out after pretty quick.
I've since switched to stock rear F-150 springs, which are longer.. 56" (early 90s or post 97 which are 57").  I've run all the above SOA.

With my flatty (46) I'm staying SUA, but want to run 31-33" tires, so I'm leaning toward the YJ springs (plus i'll be on D44s from a Waggy which had 2.5" springs).

PS-Let me know if you guys run the Rubicon.   I usually run it 2-3 times a year (plus Fordyce & others).
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Post Options Post Options   Thanks (0) Thanks(0)   Quote JeepFever Quote  Post ReplyReply Direct Link To This Post Posted: 31 Mar. 2023 at 10:58pm
My one-time experience with Rubicon was with original rear springs, and JC Whitney "stock" front springs.  They worked fine.   

In my opinion,  no lift is required,  but as Stan mentioned -> "lockers" are key. My '2A is also in the video that he shared.  It has TrueTrac limited-slip rear,  and eLocker front. It was running 6.50 SuperTraxion tires at the time,  which did fine,  but I have since switched to 7.50 NDTs that seem to do better in all offroad conditions.   For stock axles, those might rub,  but if using narrow-track Dana 44/30,  they are perfect fit. Smile

Also,  I might be outside "conventional wisdom",  but I have re-arched original springs with no negative effects.    
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Post Options Post Options   Thanks (0) Thanks(0)   Quote cpt logger Quote  Post ReplyReply Direct Link To This Post Posted: 01 Apr. 2023 at 1:50am
I also have had good results with re-arched springs. However, I do not do very much "extreme" off-roading. As far as that goes, I would be a novice to that use of our rigs.

OTOH, on the pickups, trucks & trailers that I have used re-arched springs on, an overloaded situation is not uncommon. I have had no issues in many decades using them. Of course, YMMV. 
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