Hopefully someone may have some insight..... I have a '15 Rubicon and just installed a RK 2.5 Max Travel lift with Fox 2.0 shocks and ever since I get a heavy thud when I go over an old school speed bump as if something is loose, bottoming out, etc. One thud going up and one thud coming down. It only happens when both front tires hit at the same time. No, I am not hitting it at 50mph and yes I double checked to make sure everything is tight. If I go over at an angle with one tire at a time, I don't have the issue. Any ideas ??

 

Start with your front track bar and lower control arm bolts. All these bolts need to be at 125ft lbs and unless you used a torque wrench and checked them on install they probably are not at 125ft/lbs. Then check jam nuts on your adjustable arms those need to be even tighter. Then check upper control arms I believe those are 80ft/lbs.

Your profile doesn't show what aftermarket parts you have installed. Is your jeep stock except for what you mentioned in your opening post?

 

Sounds like a loose shock

 

OK, so my dumbass just had the front track bar backwards. It looked correct and aligned perfect, but did not have enough clearance over the front diff cover. I simply reversed the track bar and made a night n day improvement to the ride !!