63" spring swap questions

[72k5mike]

Im in the middle of fabbing up some mounts for the new 63" springs. I am using leaves out of an 06 ram (pretty much the same as the chevy ones and are 31.5" centered).

I was wondering what you guys are doing for the rear shackle mount. did you move the shackle flip from the original mounts (rearward)? I am looking at the way the mounts are going to sit and there is going to be a fairly severe shackle angle leaving this mount in the same spot. If you moved it back, approximately how far?

Also, I know with the new leaf spring geometry, the pinion angle is going to be off. How many degrees should I anticipate on?

I will try to post some pics of some mounts that I have been playing with.

 

[72k5mike]

I should have also added that I am planning on keeping the axle in the factory location and I am looking for about 4" of lift. I already have the front bracket figured out, I am just having trouble figuring out the rear mount.

I do not want to move the rear mount (shackle mount) back from the original location because I have a hitch mount sitting there.

 

[projectfreedom]

I dont think anybody that does 63s is planning on leaving the axle in the stock location. When I did mine I put the DIY4x shackle flip backwards and moved it back to where the front holes lined up with the stock rear holes in the frame. I did not mess with the front spring hanger at all. I ran 7" shackles and ended up with a good shackle angle and no problem with my pinion angle. Not sure why you wouldnt want that extra wheelbase by moving the axle back. What size tires are you planning on running?

 

[72k5mike]

im only going with 35's. I really dont want to stretch the wheelbase at all as I have just finished doing some body work. I really just want to soften the ride a bit in the rear and get more flex, hence the 63's

 

[Greg72]

I do not want to move the rear mount (shackle mount) back from the original location because I have a hitch mount sitting there.

You certainly don't plan on ever towing with this thing do you??

 

[72k5mike]

haha, well, I like having the option and I also like having the secure point to tow with, although i suppose that there are other options for that. Really I dont want to move the hitch mount because it was welded to the frame by the previous owner and I dont want to start hacking welds off the frame.

In the end I will probably end up putting a different hitch mount integrated into the rear frame and that passes through the rear bumper for a recovery point. My biggest fear, however, is cutting the welds off the frame.

I am working on rear shackle mounts now that utilize the original rear holes for the shackle hanger and are a bit longer than the stock brackets. I am also trying to keep the center of the upper shackle eye in line with the original shackle bracket rear holes. I am just hoping that the shackle angle doesnt suffer too bad.

 

[Greg72]

There is nothing "mystical" about removing welded parts.... don't psyche yourself out.

Cut the offending metal off with a Sawzall, leaving maybe 1/8" of extra metal on the frame side of the cut. Then take an anglegrinder with a 60-grit flapdisc and dress-down the high spots until it blends perfectly with the frame. If you do it carefully, nobody will ever know there were parts welded on.

I don't like the idea of designing a suspension around some other part that you don't even like (the existing hitch). Make decisions based on what you actually want to end up with...then make a clear plan how to get there.

Have you already posted pics somewhere of this welded hitch thing?

 

[72k5mike]

not yet greg, I have been working late and haven't had a chance to take some pics. I agree with you though, and I will just end up cutting it off. I will take some pics as soon as I can. what should I be shooting for as far as a shackle angle at ride height?

 

[Greg72]

Generally, you want it slightly angled (forward from the spring eye towards the shackle hanger).

Ultimately, you want to insure a couple of things:

1. The shackle never travels backwards so that it gets "locked out" the wrong way when the axle droops

2. The shackle should be long enough and angled to allow the spring to get completely flat when compressed. If the shackle limits the spring movement, you are just throwing away suspension travel.


Most people agree that the stock shackle is on the short side. A longer one is usually a good idea when you do any sort of shackleflip.

 

[72k5mike]

greg, I have some pictures of what Im dealing with. the first picture is the bracket I am working on making for the shackle (there will be more gusseting). about how long is the diy4x or ord shackle flip from the frame to bushing center?


The second picture is the weld on hitch mount and yes it is welded to the shackle hanger . The last is what the shackle angle would be at droop. looking at it now I can definitely see that the angle would be too much

 

[Greg72]

Remember......"droop" isn't just what you get when the spring is uncompressed.

When you have the weight of the axle pulling down on a soft spring, that rear spring eye is going to move a LOT further forward than what's showing in that photo.

The angle does seem too severe regardless. What is the dimension of the spring if you measured along the length of the main leaf (following the curve, from eyelet to eyelet)? What is the dimension if you measured straight across from eyelet to eyelet (not following the curve, but just the most direct line you can)??

The difference between those two values will be the amount of rearward travel that your shackle needs to accomodate as the spring flatten out. Knowing that value should allow you to draw some ideas on graph paper and start playing with mounting positions.

 

[72k5mike]

yea, seems like I was jumping the gun a bit. Thanks for the help greg!