Just ordered a 5.5 critical path install last Friday. Was wondering if anybody had some experience with installation and had some tips and tricks they would like to share.

 

I'd like to know too. I'm thinking about going with their 4" kit. Seems fairly straightforward from what I've read but firsthand knowledge is always helpful.

 

very strait forward install. Measure your toe before you start so you have a starting point for alignment after the install. Soak everything in a good penetrating oil, and then soak it again. What will you run for steering? What will you run for a rear drive shaft?

 

Will probably get a driveshaft built locally and I'm thinking the cavfab steering kit

 

Wanted to give an update. I actually went with their 5.5 in. long arm kit with the fixed arms and doetsch tech shocks. I'm a shade tree mechanic, literally, so everything takes way longer than it should so any times listed are definitely a maximum if you have a decent place to work with tools and air close at hand. I am also doing this entire install solo so lots of time is also spent getting stuff and as my work spot is almost 40 ft and 4 stair steps away from my tools in the house that means a lot of wasted time for me.

First off I'd suggest getting IRO to send every PDF instructions available when you order for every part you purchase so you can read up on them. Several small things I ordered, hd spring retainers for example, had no instructions and you have to drill out for the larger bolts, which are a unique self tapping bolt, and I didn't know that and didn't have that size bit. Luckily they were still open so I was able to get the info quickly but was still out the time to go get that sized bit. No biggie really just a fyi to be as prepared as you can or the little things like that can really add a lot of time to the install. From start to 'finish', I use the quotes as I'm still ironing out several little details so although it's drivable it's not officially finished, was easily 40+ hours over almost 2 weeks. That includes a few full days and around 2 hrs or more after work for the other days and 3 days that I didn't work on it. Now since I rent I had to pick up every day so 30 or 40 min. each day was spent getting tools out and putting them up.

I spent a couple hours after work the first 2 nights checking all the parts and doing all the prep work. The xmember with xfer case skid took most of the first full day. It has to be installed and removed several times to mark holes and such. Be prepared to wrestle with this to line everything up and get all the bolts through the holes. You'll need some long socket extensions if you have the xfer skid, wobble ones are best.











The next day was spent removing the track bar and driver's side control arms and installing the y-link arm. Here is where another hiccup occurred. The upper control arm bushing on the axle was roached. Luckily the local, tho 25 min. one way for me, Napa had one. They don't rent a ball joint press and O'Reilly's' was already out so I got the 4x4 adapter kit and used the driver from my bearing and race driving kit and beat it in. Just that took over 2 hrs. so be prepared to replace that bushing. Then the nightmare of trying to line up the y-link by myself began. You can definitely save yourself some time by having help here. Pass. side was a snap.











Next issue was the track bar bracket. Be prepared to ream out some of these hole to get the bolts in as it is bent square and, at least mine is, the frame has a taper. Again, without proper tools and bench etc. this took well over an hr. and a broken drill bit and one crossthreaded bolt to get it installed so get ready to fight this one too.








Rear leafs went pretty good. No major issues there. Took about 4 hrs to r&r everything in the rear. Rest of the time was installing the brake lines and bleeding the brakes and torquing everything​ to spec. I got a Motive Products universal power bleeder. Wow. Sweet tool! Especially if your solo. If you go with the universal kit make sure the rubber seal is oriented correctly, taperd side to reservoir and don't overtighten the chain. Get 2 large bottles though as it is hard to tell how much fluid it is pushing through and I wanted to make sure I'd flushed all the old fluid and air out of the system. After one bleed cycle the brake pedal pressure was perfect.






One note though. I got their BPE's and the shocks are so long that I only had maybe 2 inches of up travel in the rear to the shocks bump stop so I took them off but it still seems like way too little up travel at maybe 2.5 in. now. I have maybe 3 in. on the fronts with the BPE's still installed so those will probably come off too. To be fair though I have Napier V2 cutout flares and if you didn't have cut fenders the up travel would probably be perfect.

Also, I did use the 1 in. xfer drop option on the xmember and have basically no driveline vibes. I plan on raising that back up in the future to see if I get any vibes. Will eventually be doing the sye and cv driveshaft.

I've flexed it a bit and the lca brackets definitely hit and will need to be removed. And be prepared to hear all kinds of new noises since your control arms now mount just under your seat and it has the more solid flex joint so sounds are easily transferred into the cab. One noise I've come across, I believe, is that the xfer skid is almost touching the xfer case. I think the 1 in. drop is making it too close, so it knocks when going over washboard type bumps. Another is a clunk from the driver's side flex joint. IRO thinks my original bolt may by worn down just enough to let that joint move a little bit causing the clunk so I've ordered new ones and will report later if that solved it.

That's about it for now. I will update again once all the little things are worked out and I can actually get her on the trails.

Here's a b4 with the 33 12.50 15 BFG km2's and Napier V2 flares on 2.25 in. lift front and 3 back.



And after. Measuring from axle tube to frame I get 5.5 front and 5 rear with the rear mostly empty. In the pic below I still have a bunch of tools and parts in the back so it's sitting a bit low. Iro says this is accurate as their kit levels the XJ. I like a rake so I will probably ad some shackle relocation brackets to dial in the rear a little higher for gear etc.

 

I've run this setup for years and love it. One thing I'll encourage though (sorry this comes after you installed everything) is to get the rebuild-able joint for the upper link at the axle housing.
http://www.ironrockoffroad.com/10681.html

Even a brand new Moog bushing up there will squish and allow the axle to roll under braking. That's my only grief with this kit that it's not included. You can observe what I'm talking about by parking the Jeep on a hill and pumping the brakes as it rolls down. You don't need to go fast. Have someone do that while you watch from the outside.

I installed this on mine after too....

 

Yeah, that would've been something I'd have purchased if they suggested it. I even asked after I'd listed all the parts I wanted if they knew of anything else I should get while I'm in there and they said no. To be fair he did mention stiffeners but that was it. I'd even forgot about the xfer skid at that point and they didn't mention that either. I'd be shocked if that bushing wasn't bad on almost all XJs so I'm surprised they don't suggest that every time. Oh well...

 

That's kind of irritating seeing that bushing cause I called and asked about using a johnny joint instead of the pen style bushing. And I forget who I talked to at iro said nothing about their own product that would work. Just said that a johnny joint would not due to the bigger size bolt. I've got all my bushings installed and ate isntalled onto my transfer case just need to swing it back in with the new cross member and install the front axle. Been super busy with work training so the jeep has been neglected

 

with installing this joint you had to drill out your castor adjustment part? due to the larger 1/2" bolt?

just confirming

 

Keep an eye on the link mount in the first pic. Did you notice that the bolt is a smaller diameter than the I.D. of the joint? On mine, I could lift the Jeep, basically unload the suspension with the tire still on the ground and roll the front tire back and forth with my hands and you could see the play in that link arm mount at the crossmember. I could torque the bolt down tighter and it would help, but after the first trip offroad, there was play again. That joint needs a 9/16" bolt, but the weld nut IRO installs is 14mm. That was really my only complaint with the kit. Besides the fact I didn't like the caster adjustment thingy, but it never caused a problem, so can't complain too much.

I love the low COG look of the front in your before pic!! Did you wheel it like that? Did the tire rub the inner fender much?

 

Correct. They have one for a 10mm bolt that won't require it but I opted to upsize which meant enlarging the slot on the bracket as you mentioned.

 

Funny, in all my research I never heard of that link bolt problem. I did get a pop from that area when I first test drove it but has since gone away. Called IRO and he suggested that the old factory bolt was worn enough to allow a little slop. He said it happened on his personal rig and a new bolt fixed it. I've ordered some and will replace and see if it ever comes back. Seems like a bit of a known issue and should be easily resolved you'd think.

No. I never wheeled it like that. I did flex it tho and it definitely rubbed. I would have had to extend the bump stops for sure with that set up.