Front Spring Eye-to-eye Length For 56-58 Front Shackle Reversal?

My 56/58 (not sure the year, title says 58, but it has factory front shackle reversal so makes me think it's earlier?) is in need of new front springs. The main leafs have some sharp bends in them.

I ordered a set from Walck's as I figured they would be close to stock as I could get, and the center to center measurement is about 3" too short compared to the springs that I took off of the jeep.

The springs I removed have roughly 38.5" center to center leaf lengths, and the springs from Walck's are about 35.5" center to center.

I'm not familiar with the factory front reversal CJ5s, with the shackles behind the axle instead of at the front bumper. What center-to-center eyelet length should the springs be after they are arched?

 

The question should be, what distance are the mounts, IMHO. I've been told you measure to the eyes with the shackle vertical (mid-travel).

Remember the old springs are flattened out, whereas the new ones will settle down and lengthen with some weight on them.

My 1965 manual shows 39-5/8" as "spring length" on CJ5.

 

The old Rancho front springs I just took off measure 38-3/8" center to center. BDS says the kit is the same as my '61 with no reversal. Shackles slightly forward.

Theirs show 38-1/4" for all early CJ5 up to 1975 at 2-1/2" lift and covers your application. Hope this helps. John

 

I did a RS swap using a stock Jeep frame many years ago. The old springs (Rancho 2.5) were a direct swap.

 

You might want to check out this thread. Even with stock Walcks springs you may end up with not enough arch in the front, since the shackle mount is in the frame vs underneath the frame. I think that is kind of a unicorn, though m38a1 front springs may fit the bill as long as they are reversed also. Not an expert, just from personal experience.
Cj-5 Verses Cj-6 Ride Quality.

 

my old springs have about the same amount of arch as the new Walck's springs, and the new springs I'm pretty sure won't fit, I've installed leaf springs on vehicles at least a dozen times, never seen new springs be this much shorter. I'll contact Walck's and see what they say, maybe I can still return them. Unfortunately I've had them sitting in the carport for over a month now, just now getting around to installing them, didn't even think to measure them when they arrived.


For a shackle reversal, at ride height what angle should the shackle ideally be? Same as a front shackle setup, about 45-ish degrees or so? But angled backwards instead of forwards?

 

Interesting. I wonder if they sent you flatfender springs….the fronts are around 36”. Can you compare to your CJ2a?

I think 45 degrees is a bit much unless you’re going for more drop. 20 degrees seems about right.

Where are you located? I have a pair of ECJ5 BDS front springs just sitting here. At one point I installed the kit but ultimately ended up fitting the longer rears up front.

 

I will check this out. I haven't seen much on shackle length verses lifted springs as there would need to be enough travel to take account of the lifted {longer} springs on
compression. I could have phrased that better but my mind works faster than my fingers.

 

At 35.5”, I’d guess you were sent the wrong springs for the front of a CJ5. I’m pretty sure its the same spring length for front or reverse shackle applications. The correct springs will be pretty close to 39”. Check the length on your CJ2a.
-Donny

 

I have new front springs on (BDS 2.5") and they make the jeep sit pretty good. with the original springs in the back, and the new springs up front, the back sits just a bit higher than the front, about where it should be IMO.

I do think I need longer shackles on the springs though, these are some unused shackles I had left over from another jeep project, I'm guessing I need shackles 3/4" longer or so? When I jump on the front bumper the spring eyes hit the frame.

 

I have never seen the shackles bolted to the frame before, all of the Jeeps I have owned had hanger brackets riveted and welded underneath the frame rails.

 

I have seen them both ways and thought this was the more common way. What do I know!
I would go at least an inch longer on the shackles or more.

 

that's how it was from the factory for the very early CJ5's, leftover from the M38-A1's I guess, that had shackles through the frame on the rear of the front springs.

 

Every jeep Ive seem with the factory shackle reversal was done like one pictured by the OP.

The military wrap spring might be part of the problem with needing a longer shackle. I would agree that 1/2" or 3/4 longer shackle is needed. Maybe even an 1". That will mess with your pinion angle a little.

 

I'll eventually address the pinion angle if needed, weld on some new spring perches.

 

Normal for M38A1 and Early CJ5.

 

anyone have a good source for grease bolts? I'm having a tough time finding grease bolts that have a shank length that I would like. I would like 2-3/8" shank length before the threads (I think that's the measurement, I'd need to double check), but almost every grease/wet bolts I see online don't share any measurements. And sadly McMaster doesn't have anything in the right size (they always have great measurements)

the grease bolts that I had in my collection I wish had a bit more un-threaded shank length than they have.

 

Learn something new every few days hanging out here.

 

Had a link that I can't find now with some different bolts. The problem is the 7/16" size. Some of the trailer supply places have bolts and would need to do a search.
I know what you are trying to achieve. Might have to be a long bolt cut, custom drilled and tapped.

 

yeah, I'm pretty sure I can drill out some regular bolts, was hoping to find something off-the-shelf. I'm sure turning 6 bolts into grease bolts would wipe out an entire weekend of free time for me, I'm slow at machining