I've got this annoying rattling in my '94 Suburban like the sound of a loose shock in the front end on the driver's side. If I bounce the car I hear a deep metallic clunking sound. I can feel it in the shock, but I replaced the shock and the sound is still there. In other words, I wasted about $50 and an hour of my time. But it must be near the shock.

It only comes while driving over bumps in the road. Ball joints? Idler arm? Control arms?

 

Could possibly be a sway bar bushing.

 

Seen this a bunch of times on these old GMT400s, my 96 also had this issue, also fixed a bunch of customer's vehicles that had that.

Always narrowed it down to the upper shock bolt being loose. Yes, yes I know you tightened it. Yes I know you replaced the shocks. Been there done that - with the truck setting on the ground with all the weight on the tires, get a LONG breaker bar on the upper shock bolt, and give them a good crank. Don't break them, but make sure both of the upper shock bolts are good and tight. You need a good size 1/2" drive breaker bar on those bolts.

Usually I see them being rusty, and usually installed with ratchet wrenches from through the wheel well. That usually works for the first ... well 2 miles. After that they're clunky. Open the hood and you can get to them that way.

 

That top bracket is actually a cupped housing about 3/16 inch thick. I thought I might bend it if I used a breaker bar, but I didn't see the purpose since it's really not meant to squeeze onto the shock head.

You've got me believing it's as simple as not using a little 3/8th drive socket wrench, which means that the bolt must have vertical play in the housing, and your suggestion is to avoid the bolt having any vertical play at all. Sounds right; I 'll report back.

 

You nailed that. Exactly right. I needed those bolts tighter. Seems like a defect to be required to tighten like that, but I'm good for now. What about the rear. Won't they now rattle just like the front?

 

It's my understanding that the 3/16 shock housing should pinch a little onto the metal core on the upper part of the shock. Yes, I agree it shouldn't be necessary, but if you really look at it, what else is going to keep the shock from wiggling vertically inside the shock housing? The bolt tightening up against the housing works to hold the shock onto the frame, but it doesn't do anything to keep the shock from wiggling in the housing. If you pinch the housing down and hold the shock bushing from wiggling, your problem is solved!

Yes, the lower bushings on the rear shocks most likely need tightening as well, but the design of the shock hangers on the rear axle seem to snug up against the shock bushing better. I personally use an impact wrench on the lower shock bolts. They're nice beefy bolts, but they can still work their way loose and allow the clearance built into the bolt holes to let the shock wiggle just enough to make noise. The upper mounts on the rear shocks are designed differently, so as long as those 9/16 bolts are tightened up, there should be no appreciable noise from those unless the frame is rusty and those mounts move (seen that too).

Glad it worked for you!

 

These are the posts that I love!

You get someone who has an older vehicle and someone else who has worked with them and figured out all of the little nuances and stupidities associated with that vehicle.

Nobody got charged a dime and I'm sure Nullhead was happy to help!