2X4 frame for my CJ2A

Terry,
This is great stuff. I always wondered why I saw some people setting up their springs with just the main leaf installed. Now I know why. I don't envision ever hauling anything in my jeep but me and a couple others.

The level of information that you guys have put on here has really shed some great light on suspension setup with leaf springs. I hope everyone else following along has enjoyed this as much as I have. Learning is fun.

There is still lots to do.

 

Q: Will I need longer spring shackles?

A: Longer spring shackles are a relatively inexpensive and effective way to get the best performance out of lifted springs. Are they absolutely necessary? No. But because most lifted springs are arched higher than stock, they're actually longer than stock. And when the suspension flexes, the shackle end of the spring moves farther than stock. That's why shackles that are 1" to 1 ½" longer than stock often allow the new springs to work better.


Chris,

One more point on this subject that most spring guys fail to mention in there never ending quest to sell high lift springs to the unsuspecting Jeep owner and that is,

The lifted spring will be mechanically longer. No Question about that! The factory frame mounts between A & B on a stock Jeep were set up for a stock lift and mechanically shorter spring. When after market folks build there lifted springs they still use the short A to B dimension , and if they did not the folks buying them would complain that they do not fit between A & B.

Conversely if the spring guy was to be honest he would tell the customer that an adjustment in your lateral frame mounting dimensions between A to B would need to be made and then most folks would then never buy his product.

Get the picture?

The longer shackle is basically a crutch to make the mechanical length longer.........the correct way would be to adjust your mounts at ride height while loaded to accept the longer spring.

There are of course some benefits to using a longer shackle at a higher angle when used strictly off road as the increased length adds to the droop of the axle.

Carry on!

 

I agree with 99.9% everything Tarry said, and I respect the eloquence he types with! Some of us know what to say and no clue how to say it.

One thing I have to take issue with is concerning "Longer spring shackles... [being] absolutely necessary? No."

In this instance, I believe they are. The factory YJ spring shackles were designed to work with factory YJ springs. They sat perfectly flat in static state where the shackle only had negative (inward) travel. Plus, the springs were limited in travel by bump stops, Panhard bars, sway bars, and short shocks.

Add an arch to that spring and you put the shackle's range of motion into the positive and negative range. Increase the spring's range of motion on top of that with longer shocks, longer up-travel due to different bumpstop locations, remove all the track and stability bars, and you simply over-exceed the stock shackle's limits. You are just setting yourself up for fore- and aft- inversions without going longer.

Get some measurements of loaded/unloaded springs, and go from there. Maybe the stockers are within applicable range, but I bet they aren't.

If you don't want the added lift, you could always go with sliders instead of shackles.

 

AHHAAA!! I was looking at that! I have no desire to do this, but was intrigued by someone who did that here. Seems like a really cool idea. Actually i did have a desire to do that, but since it seems to be not very common and therefor not a lot of info out there for me to copy, i decided to go with the setup i have. Someday maybe links and coilovers, but only if i get really bored and have to much money.

Anyway, looks like old chevy cars used this setup? saw it in my speedway catalogs.

Great info guys!

 

Those look like a good deal.
I was looking at a design similar to this.
http://www.crabtreetool.com/images/100_1092.jpg

 

Good lord those are some long shackles in that ad!!

My '64 Ford dump truck uses a slide-type design. The moving end of the spring is flat and just rubs against the mount. I'll post pics if interested.

A lot of the old-school guys I used to race with used sliders. They need a lot of maintenance to keep them working and safe, but they eliminate the slop (side-to-side swing and bushing play) that comes with the shackle. I've seen rollers, too. Those are interesting.

 

sliders
http://www.pirate4x4.com/forum/gene...ered-leaf-spring-sliders-shackle-boxes-5.html

 

They are exactly what I had in mind.

 

Cool build. I'm watching!

 

I decided to see how my shocks sit and to do that I needed to flip my spring plates around. I used to have the shocks mount in front of the axle and now they are behind. I decided that if I was going to do that I would cut off the old perches, weld on the new ones for my YJ springs and set caster.
http://www.earlycj5.net/forums/showthread.php?116757-best-way-to-check-and-set-caster
Well, I did all that and the shocks mount fine up front.

 

I was looking at my old frame and it has 3 cross members in the rear. I have only put in 2, fixed that issue. I was going to use the old crossmember, but its really garbage.


I cut a new piece and tacked it in along with the shock mounts I cut off the front of my old frame.


I know you're thinking that under compression the driveshaft is going to hit that crossmember. Nope. The differential housing will bottom out another crossmember 1" before that happens.

The old frame.


I do much better work now.

 

Remember all that issue I had with the rear tank and how I added 2" to the back of the frame? Those pieces of tube were just chamfered and welded on. Plenty strong really, but I needed to add on some recovery points. So i made these out of the last bit of 1/2 plate I had laying around and its also the same stuff I made the front ones out of.

This time I was a bit smarter and cut off the bumper and cut the slots on my mill. Still had to square up the slots with a file anyway. I drilled the holes on my old 1920s belt driven camelback drill too. That thing works so great. Turns those big bits so slow, makes chips that are really long and thick like a pine cone. No blown up end mills for me today!

The plate goes through the bumper and beyond the piece of butt welded tube.

I don't think I will have any strength issues back there


I walked around with my welder and welded the tops of all the cross members, body mounts and other points in preparation for taking everything off the frame and finish welding it. Looks ok. I have seen lots better and lots worse too.

 

Ya think?!!


Looks good. You probably know this, but wait to finish-weld the spring and shackle mounts until the project is done.

 

Thank you. I was really chomping at the bit to weld those mounts, but I won't because you told me not to. Kids are at friends houses for their half day, so i will take off those differentials and flip the frame over to weld the bottom sides of the cross members in 3....2....1.... now.

 

You'll either thank me later when you realize they were an inch from perfect...

...or curse my name when you're laying awkwardly under the completed project trying to weld them in the exact position they've been in from the start.

Either way, I'm 3000 miles away, so

 

Eh, it will be an easy weld into a rounded filet. Honestly the hardest part of it will be wire wheeling out the paint or rust if i tape it off. I could threaten you with driving my jeep out to Idaho, but I would never leave. Wait, is that bad?

 

I have tacked and then cut off everything on this frame at least twice except the plates and the frame rails. They were easy and right the first time. Would have been finish welded yesterday, but I ran out of my second 11lb spool of wire and the weld shop is closed on saturdays.

One thing that my be an issue for power later is the fact that this frame is at least twice as heavy as the old one. Manhandling it just to flip it over of stand it upright is taxing. I am not as strong as I used to be, but its still very heavy.