Hey guys I was wondering if anyone had any answers to a knocking noise in my suspension. I put a 4.5 lift on it with control arm drop brackets and transfer case drop a couple weeks ago. But a knocking noise just started when I slow down to a complete stop and then again when I take off again after a stop light. I thought it was the control arms having play in them so I tightened them up with a 8,000 lb. air gun and then tightened up the adjustment bolts but it still makes the knocking noise.
Anyone have any ideas what else to check. Could it be worn out sway bar bushings?

 

So I take it the knocking is coming from the Front?

May need a new track bar.

 

x2 adj track bar. did you ever go over it and tighten everything or did you wheel it hard?

 

Yeah I already went over everything tonight. Sway bar links were about a complete turn loose. But other than that everything wasnt too bad. New track bar though? It only has 80,000 on it and only like another 200 miles after I put the lift on.

 

Not to hi-jack the thread or anything, but would the track bar cause bump steer?

 

but did you put an adjustable track bar on with the lift? i would think you would have to have done something there or your axle would be way off center

 

With that much lift and a lot of times with evven a smaller lift, you need either a longer or adjustable track bar. In lifting your vehicle you are moving the axle away from your vehicle.

 

if the track bar is not parallel with the drag link (for example,using a relocation bracket on the track bar or drop pitman arm) it will absolutely cause bumpsteer...but it's not the only cause

 

If it's coming from the back, it could be the leaf bushings, mine make a lot of noise.

If everything is tight and it's not causing any problems, I'd just leave it be. Jeeps are by far one of the noisiest vehicles I've ever driven.

 

im gonna say its the rear driveshaft knocking around, and you need an SYE. you have everything else covered.

 

I say Track Bar if you didn't install a new adjustable one with a 4.5 inch lift. I never did see where you answered that question. The sway bar busjings can cause a popping sound to happen under acceleration and braking. If you're driving that XJ with a stock track bar in the stock mounting points with a 4.5" lift, that thing is a ticking time bomb. Especially if it's being driven at highway speeds regularly. Your transfer case lowering kit will help with vibes from the rear slip yoke, HOWEVER, there is a part 2, to a anti-vibe kit. Along with your TC lowering kit, you also have to have a set of 4 degree axle shims between your rear axle pads and your rear leaf springs to optimise for anti-vibe efforts.

 

It wasnt a drastic relocation of the track bar but I drilled a new mounting point 1.5" towards the driver size to compensate for the lift. Would a drop kit for the track bar have similar results than a adj. track bar would? Or should I just shell out the extra money and go for the more expensive TB. Also what were you saying about exle shims? It doesn't vibrate in the rear at all. I was very surprised with the smoothness and no vibes of the RC lift.

 

with a 4.5 in lift just redrilling a different location is a band aid. Moving it that far over will be a weak point. Anything over 3 inches you really should buy an adjustable track bar. Prolly should consider adjustable control arms also.

ONce you move past a 3in lift there are alot more stock parts that need to be replaced if you don't want to have problems and break on the trails.

Partially the reason why I am still at 3 gotta save up more money to move to 4.5

 

Are adj. CA really necessary even when I put the beefier Rough Country non adjustable arms on there? Thanks everyone for the input though.