Okay so I'm turning to the group to get your opinions on my issue before throwing more time and money on my JK. I have a 2008 2 Door JK rubicon with a mixmatch 3.5" lift. The lift started as a RC 3.5" but I have slowly been changing out parts and adding parts due to the RC lift not being complete. (Yes I know the story...Get rid of all the RC stuff) believe me I'm trying. The jeep was driving and handling great up until I added new heavy duty steal bumpers front and back with a 35" spare and tire carrier on the rear. Now when I go over bumps on the street like into or out of driveways the rear of the Jeep bottoms out and the bumpstops hit the bumpstop extension on the axle.

Now I know everyone will say just get rid of the RC coils and get new shocks but here's another issue. I put adustable upper control arms in the rear and made them longer by about 1" to straighten out the rear driveshaft and get rid of the angle. By doing this it made the rear springs bow somewhat. So I shortened the control arms a little and added RK coil correction wedges under the back springs to help a little. And that's all it did....Help a little. I still bottom out but not quite as bad some I'm on the right track. But my question is...... Should I pull the rear top control arms in further to try and straighten out the springs, cut off and move the spring perches on the axle to straighten out the springs or bite the bullet and order new, HD springs that will hold the additional weight? Even if I get HD springs I should really move the perches which adds more costs. I'm kinda on a tight budget so I'm looking for things I can do myself especially since I'm not a fan of my local offroad shop in the area..... Has anyone been through this and have any suggestions of where to start? Thanks!

 

Are you sure / have you checked to see that it's not your rear frame-side trackbar bolt slapping into your bump-stop? If that is in fact happening, you may need to trim your trackbar bolt and/or trim your rear bump-stop.


Rotating the rear pinion will make that happen and it will feel like your suspension is bottoming out.....


....and yes. Get rid of that RC stuff.......and don't replace it with something whack like a Mopar suspension kit.





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Depending on where your rear axle is sitting and how much bump stop you're using vs how much you need.

That's what it sounds like. That rear fender well can eat a 35" tire especially if that axle is pushed out to keep it away from the pinch on both ends.

 

What did you go and do.

What was the formal title? Mr. Roller?

 

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I ran into a similar issue on my 2dr with a 2.5" lift with steel rear bumper, frame mounted tire carrier and 35" spare. The extra 300lbs hanging off the back needed a stronger spring to stay off the bump stops. I ended up going to a 4dr 2.5" lift spring to get the back end in the air.

Can't help on the axle angles in the rear though, mine are barely above stock.

 

Thanks for the good suggestions....
Assuming I change out the cheap RC 3.5" lift springs for a stronger/HD spring. Does anyone have any suggestions on what to replace it with to keep about the same height? So many choices and options out there. HD, no HD but taller spring, progressive, linear. I'm afraid I will spend $200 on a spring that is too tall, too rough or just as useless as what I have in there now.

 

I would try MetalCloak, Synergy, or the EVO springs. I can't remember if JKS sells them separately.

RK is also an option but there have been reports of them rusting....





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They are rusting, no question on it.

 

One thing about a JK: there just isn't a lot of up travel there, so often it's about maximizing what you do have.

Once you've eliminated things like track bar bolts and other fun binding issues, it's time to take a look at your components.

How big is the bump stop extension supplied with the RC lift? Cheesy suspensions often require bigger bump stops to keep you from having coil bind, so often switching to a higher quality bind free coil will allow you to use a smaller bump stop spacer. Obviously a higher spring rate coil will help with the up travel, but it'll give you a stiffer over all ride. We like multistage springs as opposed to a linear spring for this reason, with initial ride quality being controlled by the lighter weight part of your spring, with the stiffer rates controlling larger movements that lead to bottoming out.

So, after addressing the coil, it's time to look at shocks. Shocks are really a more important part of this than people realize. You'll want to run a good quality gas shock. You don't have to break the bank on a set of remote resi 2.5s or anything, but something good and relatively stiff will do a good job of keeping the axle from hitting the frame.