Reverse shackles and braking

The jeep is starting to beat me. Sorry if this is long winded.

Looking for some people who currently own or have owned reverse shackle jeeps: I've noticed that, after I brake hard, my shackles sometimes tend to move backward. Makes sense; the brakes apply resistance, the axle is bolted to the spring, so as the axle wants to stop, the spring pushes on the shackle. No biggie. Well today I've got discs, and the discs pushed the driver's shackle horizontal and stuck. The whole body was leaning toward the driver's side. Didn't break or bend anything, just stuck.

I've got some remnants of a P.O.S. shackle job, and that is no understatement, actually I'll use another forum member's words, "death trap" fab job that a PO tried to put in. Basically they are what would be main eye hangers an a stock jeep. I left them in there because they were made out of 1/4" plate and seemed to have good welds. Anyway, I've got a pile of aftermarket goodies in the gargage waiting to fix it right, but now I'm thinking of just going back to front shackles. I'm starting to think this reverse shackle idea may be a bit over-rated. The way I look at it, unless you're running some massive packs like Dummy, I don't see how a relatively soft spring like mine would keep from flexing and shifting that axle around during braking. This jeep isn't going to ever be a daily driver, but it will see in-town use. Is there a way to fix this, or should I just use my new mounting brackets to flip it back to front shackles? The current setup has the shackles sitting at a slight angle backward when the jeep is level. I thought maybe if I had the shackle at a slight angle forward it would cure this, but I don't want them to invert, either.

 

Sounds like more than just a reverse shackle problem to me, but I could be wrong. Wouldn't be the first time!R)

I do believe that reverse shackle may have more 'brake dive' associated with it, but usually that also comes with soft spring rates that go along with reverse shackle mods anyway, so its hard to say how much affect that would have. It should by no means cause the shackle to go horizontal and stay there.

Are the springs moving in the bushings, or are the mounts moving around at all?

Kevo

 

I've think I've got 2" leafs front and rear. When I read the tech page, are those 36" and 42" measurements eye-to-eye on the vehicle. In other words, should bolt hole to bolt hole on the frame be 36" and 42", respectively.

Bushings seem to be tight. (They were apparently considered optional equipment for the PO.) Mounts are welded up solid. I think the frame will bust before the mounts do. I need to go buy a new camera.

http://www.earlycj5.com/tech/SpringsShocks/leaf_springs.shtml

 

Check out this pic of Dummy's setup. My shackles are not even quite at this angle, and yet the driver's side was able to move horizontal. I measured the mounts, and they are 42" bolt-to-bolt front with a 2" spring, 45" bolt-to-bolt rear with a 2.5" spring, so looking at the chart I have no friggin idea what the hell this guy put on there, but I did see part of a "Rough Country" stencil on one of them. How do I measure a spring to figure out what the proper mount distance should be? Do I unload the axle? I'm thinking that maybe the PO didn't use a standard CJ kit, and maybe I just need to figure out what I actually have on the vehicle and then move the mounts accordingly. I think if I move the mounting hole for the shackle side of the leaf back a couple inches, it would be at a distance such that the spring would never be able to flatten far enough to let the shackle go horizontal.

 

your springs need to be a little shorter or you need to move that hanger a half inch or so back. you have a geometry problem allowing the spring eye to brake over center.

JB

 

I have reverse shackles on my Jeep - factory - much smoother ride, but there is a bit of brake dive - my shackles sit almost vertical with the Jeep just sitting there - maybe a slight tilt toward the rear of the Jeep - this is with pro-comp 2.5" lift springs -
If you move the mount too far to the rear, and the shackle tilts the other way (spring end in front of the upper pivot, instead of behind) then every time you hit a bump, the spring will have to lift the front end of the Jeep to extend - this will be a painfully rough riding unit, until the spring or the mount snaps.

just my experience.....

 

That is one of the reasons I decided against the shackle reversal on mine. Braking and steering geomitry. My personal opinion is the shackle reversal is great for an off road machine but not right for a driver. I am sure I will get bashed for that opinion but so be it. I have also noticed that no one speaks of drive shaft mods for rear shackles. Because the axle is moving in the same direction as the spring now the drive shaft compresion and extension is greatly increased.

I am sure there was a reason that most of the jeeps were built with the shackles in the front...

I dunno

 

Roger on the break over and shackle going forward; I think this may end up stock again before it's all over.

Okay, I've been playing with the hydraulic jack and tape measure a little this morning. I think my springs may be somewhere in the vacinity of 44" eye-to-eye. Does anyone know what uses 44" springs? That measurement seems to be very close on all 4 corners, although the fronts are 2" wide and the rears are 2.5". Now, correct me if I'm wrong, but according the tech page chart, I should have 36" front and 42" rear. I think this is confirmed by measuring my wheelbase: The front hanger is mounted right under the bumper, so maybe 2" forward of stock there, but with those springs under there, I am at 79". So, now I'm thinking that in order to even use these springs, I need to get some hangers that move the front of the spring outboard of the jeep, like the ones pictured below. I really didn't budget for a whole new suspension, so I would like to re-use these, but I don't want to be sitting on a turd, either. Think I could mount the M.O.R.E. hangers up front to gain me another inch or so of wheel base, put the main eye hanger at 44", and install a new shackle at roughly vertical?

 

If it were me I would move the shackle mounts in the rear back a few inches. If you change the front. It would move the hole axle forward.

 

You have basically two options besides getting rid of the whole thing. Move the shackle mount back enough to get a better angle on the shackle or make/buy longer shackles. I set mine up so the shackles are slightly angles to the rear. If your rear brakes are not properly adjusted or are worn out you will have more front end dive when braking. After i went to rear discs it cut the brake dive by about half.

 

That's actually what I would be intending on doing, stretching the wheel base out to at least 80". Good idea or no?

I'm not wild on the long shackles, unless you could recommend one that's really stiff.

I've got the brand new shackle hangers and main mounts, so it's just a matter of cutting off the crap that's on there and welding the new ones in. I really would like to avoid buying all new springs, though.

I feel a lot of brake in the rear now that I have new cylinders installed, although I still have air in the line somewhere. I lose a lot of pedal on an incline.

 

JEEP going in to see doc on Monday. Going to torch off everything and start over. Ordered up a 3-1/4" shackle from Krage's. Aftermarket universal type '76+ main eye hangers, poly bushings and shackle hangers. Will post again on this subject maybe next week. Thanks for all the help.