FYI, this was originally posted on another JK forum, and all I get is crickets... I think maybe it was the wrong forum for me. I am a very technical person and I tend to ask technical questions a search of the science (ok physics) behind the answers. Looking through some of the other post here, I am hoping I found a better home

I am collecting the bits and pieces of a 2.5" lift. I am not a "kit" type person so I am cherry picking the items that I like based on much overthinking.

I understand an adjustable track bar or bracket or D-link flip is probably not necessary at 2.5". But I don't do things based on necessity, so lets just get that out of the way. (that's not to say I am not interested in opinions - just know it's a question of could it be better)

I have done some reading on this and I am a little unclear on a couple things.

1) If I add a raised track bar bracket (3") I need a longer bump stop. ( I think my shocks are going to need a 2" bump stop) Are there any brackets designed in such a way that do not need a longer bump stop? (not looking at frame side brackets) Looking at the front, it appears the contact point would be the frame, but I think there is some space to the inside if a shorter track bar was used.

2) Some brackets require a drag link flip and some do not. Is this simply because the company chose to incorporate both in one bracket ? or is there another reason

3) Drag link and track bar need to be the same angle for proper suspension geometry ? Is this because as the axle is traveling up or down it is going to move with the track bar the same amount as the drag link / steering ? thus keeping the steering angle the same. Seems pretty minor at on road suspension articulation. Off road low speed I can't see that the slight difference would matter.

3) My plan was to go with the JKS or Synergy drag link flip kit with the raised track bar mount . But after realizing that I need a longer bump stop, I am pausing to do a little more research.

The purpose of my build is 2.5" lift, 35" tires with a top priority of on road ride and handling and no compromise in quality. The benefit of the raised roll center is what I am after.

Other pieces that I have already amassed for this project are: Rock Krawler 2.5" springs, Fox 2.0 shocks, RK rear track bar bracket, RK rear sway bar links (I believe I can swap the rears to the fronts), RK spring wedge (cant hurt), 315/70 17 K02s on Pro comp wheels. I will machine my own bump stops.

Items to be sorted out in the next week or two: Full set Core4x4 control arms w/rubber bushings (probably skip the track bars unless the axles don't center with the brackets.) And the Front control arm bracket / drag link flip. Plus some little odds and ends - brake lines etc.

Thanks for the help

 

I would not use RK components if you are piecing stuff together as their componets don't play nice with others. Reason is that they have poor engingeering and take advantage of peopel that don't understand suspensions and care more about instagram photos of jeeps with one wheel on a rock. Its a poor company with poor performance and service. Good luck if you ever need their warrantee. I would use Rough Country before I used RK. If you can, send back the RK stuff and you can get better components for cheaper. Don't use rubber bushings on the arms as they will not last, just go with the johnny joints. Cut the axle side factory coil perches, rotate them forward, and weld them back on. Very simple to do and takes about 10 min. Metal Cloak has a nice stackable bump stop set up that allows you to fine tune your set up. Persoanlly I use stacked 3/8" aluminum bar stock for bumpstop pads.

You need extra bump stop so the drag link and track bar bracket don't hit the frame at stuff. You can also notch out the frame on the passenger side to allow the up travel and not have the conflict the drag link flip creates.

For the best results the track bar and the drag link should be as close to the same length and paralell to each other from center of mount to center of mount. They should aslo be as paralell to the ground as you can get and the reason for the drag link flip. Uneven lengths and steep angles cause bump steer so when you drive over a rock or drive around a banked curve with non paralell links will cause the steering wheel to move and the axle will shift. You don't want to raise the track bar without flipping the drag link. Some companies will use a drop pitman arm with a raised track bar bracket. This does not raise your roll center and puts more stress on your steering box. Synergy is a good drag link, so is Metal Cloak and there are kits for the DIY guys that save you quite a bit https://www.barnes4wd.com/JEEP-JK-1-...LE_p_1135.html. I recommend doing weld on brackets vs the bolt on crap that is out there. I do this a lot and use Barnes 4x4.https://www.barnes4wd.com/Jeep-JK-Re...ket_p_416.html and https://www.barnes4wd.com/Jeep-JK-Fr...et_p_1192.html Typically you can buy both brackets for the cost of the bolt on junk that is out there.

good luck.

 

If you are getting a full set of adjsutable control arms, why are you looking at front control arm brackets?

 

Ouch! I was under the impression Rock Krawler was pretty good quality. The reason I picked the RK springs was I had spoke with someone at Core4x4 who said the best riding JK they had was their control arms with RK springs and Fox shocks. With a triple rate spring that makes some sense because most of your on road ride is going to use the softest area of the spring.

I had not thought about notching the frame... that is a great suggestion.

Also thanks for the Barnes 4x4... that is a good find for the brackets.

(I may have said control arm brackets along the way, but what I meant was track bar brackets)

 

Thats another thing RK does is call their coils tripple rate, while it is correct that it has three different winding rates, you only drive on one rate. The upper windings are only used when fully drooped out and don't affect the ride quality. The other two rates work as a single rate due to no stop in the system unless the lighter rate is fully compressed which will only happen at full stuff. I have been in several RK equipped jeeps and they are some of the worst riding kits out there.

 

Was wrangler forum the other place you posted on? Those mods are a bunch of idiots pushing crap on people and can't think out of the box.

 

I will decline to name names. I did not spend much time over there, or any forum for that matter, as this Jeep is new to me and its been about 10 years since I owned a TJ. But after a few posts my feeling was that the group was not the most technical. I want the guys that are cutting frames, welding brackets, fabricating their own parts, etc. I don't care about what LED bulbs fit what (although I do need to do something about these terrible headlights LOL)

 

 

YES! that is awesome. But I am not going that far... not that talented !

 

I have the 2.5" MC lift (not entire kit) and did not see the need to address the front TB raise or drag link flip as you would end up with big notch in the frame for such a low lift height or limited flex. Bump steer is not an issue in mine now as the TB/DL bars are parallel. More suitable for 3.5" and larger lift but Dirtman is correct if you get the bars more parallel to the road it is better. The big improvement I did was raise the rear TB and centered the diff with adjustable MC setup. No ass wobble any more going over those undulating angled bridge joints etc. I recommend you try that first and if you feel the need then go with the front TB/DL changes. Your wallet will thank me.