Rear suspension clunk noise after lowering

Here is whats going on. Last summer i installed Belltech 2/4 drop kit in my 16 Denali that have 40k miles. Still have OEM shocks and struts. After a few months i start having clunk on hard acceleration and on hard braking, looks like it will clunk once on acceleration and wont clunk again on avveleration unless i hit brakes hard, than will clunk, and its like sequence. I checked all bolts, all tight. Also if im slovly breaking and if that time i ran over bump it will clunk. I think it maybe spring they way it sitts in OEM insulators. But they in place. Spring sits straight.
Checked Eibach swaybars, and Wilwood brakes, lhey also tight, nothing loose.
Im not sure about body mounts, but at 40k i dint think they are going bad
Anyine have any ideas or did anyone have same issues

How much play do you have between you’re rear drive shaft and axle? Both rotational and axial.

When you lowered the rear, did you have to adjust the angle of the rear axle for proper shaft angle at the rear differential?

There is some play in pininon. I do have DJM kit that fixes driveshaft angle but didnt installed yet
This isnt ratteling noise, its just like crack or clunk noise but only once on hard suspension compression and rebound

I recently had a very similar situation on my lifted 17...during inspection i removed the track bar ( lateral link behind diff), the ends were JUNK at 78K, BOUGHT NEW from dealer and all was fine for a few trips, then it started again.

finally chased the noise down to bad endlinks on rear sway bar. do not discredit the small items during inspection. i even went as far as o purchase 2 sets or rear coil insulators and install those at the time of the track bar, one on top of coil, one in between coil and lift spacer...all over a bad end link

Slow5.0 said:

There is some play in pininon. I do have DJM kit that fixes driveshaft angle but didnt installed yet
This isnt ratteling noise, its just like crack or clunk noise but only once on hard suspension compression and rebound

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I know some folks have had issues similar to yours and putting some good grease on the splined slip joint solved it as it was binding a little and at full compression and full extension it would let loose.

Im using DJM offset endlinks. Looks like front end started to make same noise. Up front i have new Moog endlinks. Its either those suckers or willwood brakes. I dont think its driveshaft or springs. Or maybe all 4 OEM shocks/struts at 47k ?!

wjburken said:

I know some folks have had issues similar to yours and putting some good grease on the splined slip joint solved it as it was binding a little and at full compression and full extension it would let loose.

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I just pulled driveshaft and grease spline and even outside little bit. Driveshaft came out transfercase nice and easy. Both U joint are nice and tight, no play so they good.
Looks like greasing helped little bit. Ill have to drive some more and see if noise goes away. Next thing is to instal DJM kit to fix driveshaft angle

I think this clunk its comming from front. Have to be those dam end links, with Eibach swaybar end links doeant sit straight up like OEM setup. I will order new 3/8 lond threaded grade 8 bilts from Mcmaster and see if that helps. Moog bolts are week, they bend easy

Installed new Moog front end links with 6" grade 8 fully threaded bolts and greased rear DJM offset end links and Spohn panhard bar. Look like clunk noise is gine for now. I did found old some rubbing on 6" bolt i was using on front end links. It was rubbing against lower control arm, right between bottom bushings

I had the same issue when I dropped the suburban. I ended up being the control arm I had loosened and didn’t torque to spec again. Drive me crazy and has the same symptoms you described. Might wanna look there if it comes back.