Direction/Feedback Needed

[jrienzo4]

So, I was wheeling the other day, and finally decided I am not happy with my current setup (primarily suspension) So now I am planning a new build-up for my XJ, and I wanted to see if there are any suspension gurus on here that could help give me some pointers.

Current build:
1999 XJ (4 door)
Rebuilt 4.0, with AX15 & NP231
Stock Axles with 4.88 gears
4.5" Rough Country lift (w/o Long Arms), pushed to 5.5 with new rear shackle mounts & new front springs
Currently running 35's (33's in picture)

What I want (I think):
37's, low lift (about what I have now).
MUCH more travel down for both front & rear suspension.
I have a set of 2004 Super duty axles, with trusses (D60 & Sterling).
I can weld, I have DOM bar, a bender, etc.
I plan to add a doubler transfercase.
I am building the roll cage first, along with frame stiffeners. That's this coming summer's project.
Once that is done I will build the front & rear suspension.

Here is what I don't know:
I assume I will be putting in coil-overs, although I don't know anything about them...
How do I determine travel... How do I determine spring weight...
I assume I will need tall towers (even out the hood up front, and into the cabin for rear) - I just don't know...
Should I push back the rear axle...
What's the pro's and con's of keeping the lift relatively low...
4 link vs 3 link - not sure the pro's and cons here either...
Also - drivelines - I've seen people do square tubing, inserted into larger square tubing to give the drive line some stretch - is this a legitimate way to go?

I am in Washington, so my offroad use will be primarily mountainous trails, where technical finesse beats hp. This won't be a rock bouncer.
And while I realize the rig will be essentially off-road only, I will TRY to keep it usable on roads (where I live we are all just a bunch of rednecks, and the cops don't care if we drive these things on the road).

Any advice on the above topics would be appreciated!

 

[XJ_ranger]

Lots of questions with lots of if-then answers in there.

I'll add a few more:
What is your plan for steering? Keeping a steering box or fully hydraulic?

What is your budget?

What do you not like about the capabilities your currently don't have?

Do you currently have long arms or a drop bracket setup?

Do you intend to drive to and from the trails?

Do you have any lockers?

Are you planning on keeping the 231J transfer case?

 

[jrienzo4]

Yeah, I get it... there is a lot of variables in there, as I'm in the planning phase...

I plan to keep the steering gearbox, unless there is some mechanical reason to switch to hydraulic, due to the geometry changes with increased travel.

As far as budget, I'd like to keep things as manageable as possible, maybe $10K or less...

I have a drop bracket setup, no long arms.

I currently trailer to and from the trails.

I currently have an Aussie locker in the rear.

I do plan on keeping the NP231.

What I do not like about my current setup is:
1. I have no suspension flex down (I do not have long arms, and I realize that makes a huge difference...).
2. I am in constant fear of breaking axles or u-joints due to the 35's on stock axles.
3. I have no cage, and I would like to get more aggressive in my wheeling trips, in which my kids are with me.

Since I am putting the one tons underneath, I figured I would be building the long arms myself (or buying a kit and modifying it for my setup). Since this is already the plan, I figured this would be a good time to build new suspension brackets and get a lot more travel. Even if that means cutting up the rear (body aft of the wheel well) and pushing the rear axle back a bit further to allow more up travel in the rear.

I do plan on putting a lot of work into this thing (way more work than $$$) - like removing the roof, and building a custom vinyl roof with snaps, possibly ditching the hatch door for a side open door with netting, etc.

All of the above I am fairly confident in fabbing, with the exception of the suspension/drive train questions above... But I am an open book and will take ANY advice from folks about this build.

 

[XJ_ranger]

Well, there is a lot going on already, but I think to make this manageable, I'd consider breaking it into phases.

Like, do frame plating, sliders and cage (leave the roof for now) and get that all done, buy a spare set of ball joints and some junkyard axle shafts for $150 and go wheel some more.

Then get the new axles, wheels, tires, gears lockers, suspension joints, link material, steering joints and steering material, rear leaf springs and shocks, coilovers, and have all that on hand, and axles ready to go, then start the axles swap.

I think if your keeping a steering box, which will be rough with locked 37's, you'll be looking at a 3 link with a panhard to keep the axle moving with the drag link together.

As for coilovers, and most linked suspension in an existing vehicle, it usually best to put the axle at whatever full compression is (usually in an XJ, that's the front axle truss hitting the oil pan or the panhard bar hitting the oil pan) then start mockup with the coilovers you intend to run fully collapsed, and cycle everything- and that determines the upper coilover mount location.

My pro-mod comp buggy runs 12" travel shocks in the front, but a lot of folks pick 14" travel shocks. 16" and 18" exist, but are really difficult to package in the front of an XJ on a turning axle, and a lot of the time, the balance in jeeps of the XJ era (TJ, ZJ, Linked YJ conversios) with coilovers ends up with about 4" of up travel in the front and the rest as droop travel. The more steering angle you go after and if you decide to narrow the axles at all, the harder it will be to make it all fit.

Stretching the wheelbase is almost required in the front with 37's because the firewall can't move much before your pedals don't work, so folks usually end up 2 or 3" forward there. Stretching the rear usually requires a fuel cell and removal or relocation of the factory tank, which eats cargo space.

The axle swap will require some change in driveshaft, regardless. Usually the square tube stuff is reserved for the most budget minded wheeler, though there isn't much in between the $50 square tube welded myself shaft, then $200-$300 worth of junkyard driveshaft parts and a home re-tube job or the $450+ aftermarket options like adams, Tom woods, JE Reel, and similar companies.

The options are really all up to you, though I think that a set of wheels and tires, gears bearings, lockers, u joints, shafts for new axles, driveline mods, link material, joints, steering joints and material, cage material, coilovers and springs for them, rear shocks, potential fuel cell and pump... is going to far exceed 10k in a quick hurry.

Where in WA are you located?

I'd wager the front suspension could be re-worked, and a front axle truss, 30 spline locker, alloys and good u joints (or RCV's) could be done for under $4k, keep the 35's, gain the flex and confidence in the front end to go pretty much anywhere in WA or the PNW that a full body XJ needs to go, and could be done in a few weekends depending on the suspension choice.

 

[jrienzo4]

Hey thanks for the indepth feedback, man - I appreciate it.

As for keeping it below $10K, that's just a rough target. I will end up doing all this in stages over the winter(s) so it's not a hard stop at $10k.

So based on your feedback, here is what I am thinking:

Phase 1
Build the cage first - at the same time do frame stiffeners & sliders grab some extra axles for when I break. Go wheeling.

Phase 2
I already have the new axles and wheels (will need tires). Throw Aussie locker front and rear (or maybe weld the rear). Install with long arms. Go wheeling.

Phase 3
Determine if my wheeling style really needs coilovers, if so, deal with that as it's own upgrade when (and if) the time comes.

By the way, I am in Buckley, WA so I spend most of my time at Evans Creek, & Naches, but I do go up to Tahuya and Walker Valley too.

 

[jrienzo4]

...grab some extra axles for when I break....

I (of course) meant axle shafts...

 

[Goose_XJ88]

Not sure what arms and drop brackets you have right now but my Rubicon express pair has quite a bit of droop.

Sliders: Id recommend cutting out the rockers and doing the 2x6 tube steel replacement with a tube step/standoff. Only replace the rocker so you dont have to cut the doors. Much easier, faster, less work, and you arent loosing that much vs going all the way to the door sills. Its also easier to add the kicker legs to the "frame" without going through the floor.

 

[Phil]

Trailer to trails + selectable hubs + tons says, to me, weld the front and open or locked rear.

Hard to believe it has been almost six years since green junk went away but 14” coilovers are a lot for a full body junk. Agree with the comment above that 12” travel coil overs are the right size.

Also, agree short arms and drop brackets should be pretty good for a full body XJ. Are your current front shocks limiting droop? Brake lines? Or lower control arm on the axle-side bracket?

 

[75SV1]

Steering setup and brakes?

 

[Evan03]

Your on the right track.

Id recomend 12-14 coilovers in the front.

12" gives plenty of wheel travel. Shoot for 5" of up travel and 7" down from ride height.

Stinky fab 3 or 4 link flip a coin both work great.

In the rear 14" coilovers with tringulated upper links. Lowers dont need ti be tringulated just make them fit.

Link seperation for 37" tires on axle should be 10" minimum. Id build in some link seperation adjustment. 10-13"is

On frame side link seperation doesnt need to be ad much.

You want links as parralell to ground ad you csn get them.

Accutune, foa, filthy motorsports, stinky fab are all good resources to have on speed dial. Can help with spring rates link geometry steering idea's.

Lots of giid resources online but even more misinformation be careful. Be willing to test tune try hate it. Cut it apart and start over. Thats why building some adjustment into the system if possible can be a good send.

Lower is better revolving arent great steering.

Ori struts could be a game changer aswell. Spendy but i think worth it.

Correct put together it will excell on the trails and be a dream on the freeway all your friends are jealus of.

 

[jrienzo4]

Thanks for all the feedback, guys.

So I've found my restriction on flex is primarily due to control arms binding up (short arms w/of drop brackets). First thing I'm going to do is get a set of drop brackets. That will keep me wheeling (happier) for the next year, while I get the one-tons ready and purchase the cage kit (still debating between the XO Fab and D&C kits).

Hopefully, by next summer I will have the cage done. Then it's off to the one-ton conversion. I'm betting that the 14" coil overs are the right thing to my use, as you all have suggested.

And during the one-ton swap, I will hopefully be 4 linking the rear.

 

[Phil]

You indicated in post #3 that you have drop brackets. If you actually just have short arms in all factory brackets, at 5.5” of lift, drop brackets for a couple hundred bucks and a weekend of effort is definitely something you should try.

 

[Evan03]

Buy one of those diy ebay bumpers to hone your welding skills.

Aslso with goose do weld in 2x8 rockers

Youl love control arm drop brackets

 

[jrienzo4]

You indicated in post #3 that you have drop brackets. If you actually just have short arms in all factory brackets, at 5.5” of lift, drop brackets for a couple hundred bucks and a weekend of effort is definitely something you should try.

Yes I apparently did... My bad. I meant to say i have them coming. I purchased the RC bars off Amazon, they have not arrived yet, (so I won't have them installed for the Labor Day trip).

 

[jrienzo4]

Buy one of those diy ebay bumpers to hone your welding skills.

Aslso with goose do weld in 2x8 rockers

Youl love control arm drop brackets

I agree on the rockers. But I don't know if I want to keep doors... so I may do something different. When I took them off this summer, I was like "I'm never putting those on again." I've been thinking about clear nylon covers (or whatever soft top windows are made of) that snap on... I don't know, haven't really thought too hard about that. Fortunately I have a decent sized garage.

And I'm good to go as far as welding/fab stuff. But that is good advice. I've built motorcycle frames, and had many other welding projects. Plus I already have front and rear bumpers installed - Smitty Build with tire carrier in the back and RC in the front. When)if the welding seems over my skill set, I have some close friends that are professional welders.

 

[jrienzo4]

Not sure what arms and drop brackets you have right now but my Rubicon express pair has quite a bit of droop.

Sliders: Id recommend cutting out the rockers and doing the 2x6 tube steel replacement with a tube step/standoff. Only replace the rocker so you dont have to cut the doors. Much easier, faster, less work, and you arent loosing that much vs going all the way to the door sills. Its also easier to add the kicker legs to the "frame" without going through the floor.

Thanks man - I'm surprised how much flex the drop brackets allow. I never even heard of them until a week ago or so. I planned on long arm, but haven't been willing to buy them, due to the fact that I plan on putting the one tons On in a couple summers... Seemed like a waste of I couldn't adapt most of it. But the drop brackets aren't expensive, and look like they really help! Excited for mine to show up!

If I end up deciding to keep my doors, I'll go this route for sliders, but I'm still on the fence about doors.

 

[David_Bricker]

I started out with 4.5" RC lift, no drop brackets. Front travel was very disappointing. Added drop brackets, and it made a world of difference. I probably could have / should have left things alone at that point, but nooooooo.

I'm now on a Rockjock D60 front with PSC hydro assist, 3 link, D60 rear, Deaver springs, 12" travel shocks, caged, blah, blah, blah. Does it ride better and perform better? Absolutely. Am I less likely to break anything with my gentle style wheeling? Absolutely. Was it worth probably around $18K all in? Most definitely not.

The idea of doing it in stages is an excellent idea. You may find you are happy with only part of the phases, and save yourself some serious coin.

David Bricker / SYR

 

[jrienzo4]

I started out with 4.5" RC lift, no drop brackets. Front travel was very disappointing. Added drop brackets, and it made a world of difference. I probably could have / should have left things alone at that point, but nooooooo.

I'm now on a Rockjock D60 front with PSC hydro assist, 3 link, D60 rear, Deaver springs, 12" travel shocks, caged, blah, blah, blah. Does it ride better and perform better? Absolutely. Am I less likely to break anything with my gentle style wheeling? Absolutely. Was it worth probably around $18K all in? Most definitely not.

The idea of doing it in stages is an excellent idea. You may find you are happy with only part of the phases, and save yourself some serious coin.

David Bricker / SYR

Hmmm. Yeah this is something I probably needed to hear. I wheel pretty gently too, as my rig is not "stiffened" yet, I have no cage, and my kids are young.

I tend to jump "all-in" on projects too quickly. Realistically from what I have been researching, the drop brackets will satisfy me for a long time. Just need the cage for safety after that. Who knows. Maybe that's all I need .

Here is another question - I removed my Aussie locker last year, because it was annoying me when I used to DD my jeep (I no longer do). Would you put a rear Aussie locker back in an 8.25 axle while running 35's? Or am I just begging to break an axle on every trip?

 

[David_Bricker]

I'm a big fan of ARB lockers; expensive, but basically the best of both worlds. My experience with the service department (through no fault of the locker) has been outstanding.

A 29 spline 8 1/4 should hold up to gentle use with 35s. I was on an 8 1/4 with an ARB until I switched to th60, and had no issues.

Also, if you are going to do a cage, seriously consider a hybrid cage. My cage has no bars inside the cab by the front seats, as there is very little room for them. I have both inside outside bars at the B and D pillars(2 door); outside bars at the A pillar. The outside bars tie to the sliders and the bumper; the inside bars tie into the frame stiffeners. Now is the time to do stiffeners and sliders, and tie the cage into the stiffeners and sliders.

David Bricker / SYR

 

[Goose_XJ88]

Yeh, the drop brackets bring the geometry back closer to where it should be. Got to think about it in simplest terms; the arms are the radius of a circle. If they are flat, they have a lot more ability to move up and down in the circle . If your arms are already pointing down, you won't have much droop and the tire would have to go forward before it would compress.

I honestly love wheeling small tires and stock axles. Makes things challenging and fun without having to go insane. I'm always the small guy on 33s open/locked but I still blow my friends minds when I am able to do a line they didn't think an open front could do. Even after years of wheeling with them, they still say "your lockers not working" and I always have to remind them I'm open. Haha

And the thing I've found is exactly what Bricker said.. most people who have tons under their rig love the durability and piece of mind aspect but when sitting around a camp fire will always talk about how they miss wheeling a simple rig on 33s or 35s; yest still ask you when youre going to upgrade your rig. Lol. The other thing is I usually have about the same axle clearance at the dif bc of how large the 1ton stuff is even when they are on 37s or 40s