YJ Spring Conversion: 1955-1975 CJ to YJ Spring Conversion (2024)

Description

1955-1975 CJ to YJ Spring Conversion

Flex and ride comfort… As offroaders, we just can’t get enough of this stuff. But on older CJs this is next to impossible to achieve. What to do… what to do.

Easy answer? Swap out those stiff CJ springs to some nice soft Jeep YJ Wrangler springs. No doubt you’ve read all about this swap for the newer model CJ’s, but there has never been an easy bolton kit to do the same for older CJ’s. Rocky Road pays attention where all the other suspension companies have ignored… we give you a simple bolton conversion kit for installing Wrangler YJ springs to your CJ 5, CJ6, or M38A1 from 1955-75. Our new kit gives you an easy way to bolt on more articulation with out any adverse effects at all.

You want SICK flex and EXCELLENT ride quality…. chuck those old CJ springs and pick up our Wrangler spring conversion system. Your CJ will ride comfortable and stable like a modern SUV, and flex like a competition rock buggy. We also carry brand spankin new Wrangler springs for those who want factory fresh instead of used (although used Wrangler springs work great too) and Old Man Emu Wrangler springs for those that want the best riding lifted Wrangler spring on the planet!

Beyond flex though, ride quality is dramatically improved with the Wrangler spring conversion. Stock springs can and oftimes do ride a bit like an old military pickup truck. Wrangler springs though, they will make your old Jeep ride smooth and comfortable.

Changing to the Wrangler springs on the older CJ’s requires a more substantial adaptation than the newer CJ’s. But our kit still makes it an easy bolton process which ANYONE can do. Pictured at right you can see part of our front conversion kit. The front requires a frame forward extension as well as wider mounting for the new 2.5″ springs. The rear of the front springs must also be adapted, as well as some other elements.

On newer CJ’s, no adaptation is needed at all to run the Wrangler springs in back. On older CJ’s though, again you do need different mounting positions and a wider system overall for those Wrangler springs.

Our kit gives you what you need for this and some of our optional items can make for an even easier and higher quality end result.

Why Choose an RRO CJ to YJ Spring Conversion?

Some folks have asked us about shackle reverse kits when converting to the Wrangler springs….

We did used to carry such a system for the newer CJ’s. However, we found that Jeep (along with Toyota, Nissan, Suzuki, and other vehicle manufacturers) put the shackles in the front in short-wheelbase 4WD’s for a reason…. SAFETY.

Running shackles in the rear on a short-wheelbase vehicle like a Jeep CJ makes the vehicle highly unstable under hard braking (which is usually when you need your brakes the most). Further, shackles reversals on the CJ create axle hop under braking. After seeing a Jeep coming off of Lion’s Back in Moab with his front axle hopping and a resultant total loss of control, we swore off shackle reversals forever.

Putting the shackles in the rear may seem like a cool way to go and you may read about smoother ride quality, but the bottom-line is that the vehicle becomes unstable and the ride quality of just using Wrangler springs alone with the shackles up front as they should be is as much comfort as any Jeeper could ever ask for.

Take a look at a frame off tour of our CJ to YJ spring conversion using Old Man Emu leaf springs.

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CJ to YJ Spring Conversion Kit

In a nutshell, the Rocky Road Wrangler spring conversion kit is super simple to install, greaseable suspension, Heavy Duty Ubolt skidplates (or top plates), hardware, conversion bushings, custom shackles, and brings the ride comfort and capability to a whole new level. The same kit works for all CJ 5/6’s and M381A from 1955-75.

Using stock Wrangler springs (over stock CJ springs), this kit provides about .5-.75″ of lift boost. We also have Hi-Shackle kits which provide an additional 1″ of lift. So using stock Wrangler springs you would finish with about 1.5-1.75″ of new lift with the HI-Shackle kits.

Rocky Road also sells Jeep Wrangler springs, both stock and Old Man Emu lifted springs (for a total new ride height of about 3-3.5″), which will work on your CJ after the conversion. Old Man Emu springs are the finest lifted spring on the planet, no one can dispute this.

For Jeepers who are keeping the springs under the axle and want to see more information about our highly rated Heavy Duty Ubolt skidplates which are included in the spring under conversion system, check out our Heavy Duty Ubolt Skidplate kits.

Jeepers looking to maximize their lift height for Large tire, our Spring Over Axle kits are also VERY popular and a great way to get up into the 6″ lift range. Please be advised that If you do wish to use our Wrangler conversion and SOA kits in combination, this is a special ‘Combo’ kit which is posted lower on this webpage. Choose the SOA/Combo kit on this webpage if you have a 1972-75 Jeep.

• Our kit that is listed “with any SOA” kit comes with the necessary wider Ubolt top plates for those who are already SOA, planning an SOA, or who have swapped axles to any other than the stock Jeep D30 front and D44 rear.
• Our kit that is listed “for spring under” kit comes with the necessary wider Ubolt skidplates… everything needed except for the springs and shocks.
• Custom builders can purchase components of all our kits individually ‘a la carte’, though our kits are HEAVILY discount over piecing the same together from individual components.
• Old Man Emu conversion kit will provide approximately 3-3.5″ of total lift. With the HI-Shackle option, the OME suspension is 4-4.5″ of total lift.

Some of the details or contents of this system may be a bit confusing. Please do not hesitate to contact us if you have any questions at all regarding this Spring Over and Wrangler spring combination system.

SOA and YJ Spring Conversion Combo Kit

For those wanting to completely transform their CJ. In a nutshell, this system includes everything in our Wrangler conversion kits listed above and our SOA kit for CJ’s 1972-1975 combined for a full integrated system. If you are considering Wrangler springs on a Spring Over Axle setup, we recommend this all be completed at the same time. This kit gives you everything you need for that to happen.

The ingredients list below shows what you are getting with this combination system…

• Front and rear bolt-on anti-wrap spring perches
• Bolt-on shock mounts
• Ubolt plates
• Transfer case drop kit
• Front brake line extensions
• Rear brake line extension
• ZLink steering correction
• Ubolts and hardware
• Front and rear shackles
• Front and rear spring hangers
• Front shackle hangers
• Easy to follow instructions

Some of the details or contents of this system may be a bit confusing. Please do not hesitate to email us if you have any questions at all regarding this Spring Over and Wrangler spring combination system.

This suspension system truly is the ULTIMATE that you can install for ride comfort, highway safety, Offroad capability. There is no match in the industry for this suspension and the improvements it will make upon your Jeep. And coming soon… OTT High Steer kits for your 1972-75 CJ!!!

*Front driveshaft may need to be lengthened or may need a rear CV style driveshaft. Our test Jeep CJ5 did not, but every Jeep is different.

*Designed to be simple bolton for D30 front, and D44 rear axles. Other axles may be used, but some modification may be needed for tight fitting, and welding may be necessary for installation

Additional information