Increasing rear flex!...

After spending a lot of time searching I still haven't found exactly what I'm looking for.

Currently I am running about 4-4.5" of lift from various companies. The leafs are a bastard pack with an XJ main and dakata leafs. Also have some 1" extended shackles. Recently put in some new front springs (with a greater spring rate) in an effort to make my rear leafs work more. While I think that it did cause the leafs to do more work, they just don't have enough flex. They seem to quickly run out and I will start to lift a tire in the rear.

My question is where to go next. I have read on how to reduce friction (full-length liners, etc) in this thread http://www.naxja.org/forum/showthread.php?t=23381&highlight=leaf+spring+tuning
However, I am not really wanting to try to rebuild an entire bastard pack right now. I am considering purchasing some new leaf springs, but am not sure how much it will help. Have heard that RE doesn't seem to do real well in the flex department, so I am considering OME or Deaver. With the OME I would most likely have to run their AAL to get my 4-4.5" of lift (using shackles).

Have also looked into rebuilding the shackle box to fix shackle angle, but I don't know if I would be able to do this too well with the amount of lift I want to run. Seems as though I would be running a small leaf pack and they would be really flat, allowing for almost no uptravel before inverting. Also, my shackle angle does not seem to be too bad right now...Prob about 10 degrees back or so. I'm thinking that I could maybe fix this by running a slightly longer pack/main leaf to better shackle angle...maybe with a boomerang shackle.


Ideas?...suggestions?...

Try a longer shackle, I think the longest is 1.75 inches and then go for some 3 inch leaves.

I run rustys 4.5 inch leaves and they flex alright even though I still have the stock shackle.

Ive heard that a flat leaf pack will give the best flex, or one that has minimal arch to it. I dunno if this helps or not.

-Alex

Flat leaf pack = better flex...

my suggestion for your 4.5" - 3" OME leaves...1 or 1.5" shackle....and if you need a bit more, 1" U-bolt eliminators from TNT

I run just a hair under 4", with OME packs and a 1" JKS boomerang....personally, i love the amount of flex i get out of that size lift.

JNickel101 said:

Flat leaf pack = better flex...

Click to expand...

X2. Here are a couple of poser shots of mine at 5" with a bastard pack and a re-located mount. I used a longer main, F-150, but the benifit would be the same with an XJ spring. The main thing is getting a good shackle angle, and as little friction as possible, but all I did was sand and paint the leaves.

The best flex I ever had was with a 3.5" bastard pack, 1" block and 2" shackle. Flex like a mofo and rode nice. It doesnt flex quite as well now (RE 5.5" HD leafs and 1" boomerang shackle) but it takes a load better.

Remove a leaf and get a longer shackle. If it sags put in a small block (1-1.5" wont really cause the wrap problems you see with bigger blocks).

increasing the flex in a leaf spring is like redesigning the wheel to see if it rolls better... bastard packs in my opinion will not flex as well as a matched leaf pack because the different rates of the leafs can work against eachother.. ive always liked the way my RE 3.5" packs worked with a longer shackle.. it would compress and extend just fine. certainly nowhere near the amount of flexibility in the front coils but thats the nature of the design. a longer-than-stock shackle will give it a little more but it will only go so far. a "loose" and flexy leaf spring generally wont last long anyways.. i like the predictability of the loose front end firm rear springs. although the next XJ i build is without a doudt going to be a coil conversion. same deal with YJs.. you can loosen them up an insane amount with revolvers and Z boxes.. but if you limit yourself to a stock-type shackle you just need to get comfortable with hanging a wheel on every obstacle..

JNickel101 said:

Flat leaf pack = better flex...

my suggestion for your 4.5" - 3" OME leaves...1 or 1.5" shackle....and if you need a bit more, 1" U-bolt eliminators from TNT

I run just a hair under 4", with OME packs and a 1" JKS boomerang....personally, i love the amount of flex i get out of that size lift.

Click to expand...

Are you running the regular 3" OME packs or did you add the add-a-leaf too?

cal said:

The best flex I ever had was with a 3.5" bastard pack, 1" block and 2" shackle. Flex like a mofo and rode nice. It doesnt flex quite as well now (RE 5.5" HD leafs and 1" boomerang shackle) but it takes a load better.

Remove a leaf and get a longer shackle. If it sags put in a small block (1-1.5" wont really cause the wrap problems you see with bigger blocks).

Click to expand...

Similar to what i run..... 3.5"RE pack with a 1" solid steel block (7" long on 7" M.O.R.E spring perches) pinned to the pack with a longer center bolt & 1 1/2 shackle. It really is pretty damn soft and flexes well.
I am still thinking about doing a Deaver pack in the future for added control but for now im quite happy.