1996 Suburban Suspension Issue

[Roy Martin]

Before you go that route if you spray the rear suspension with water does it get quiter or muffle

No change. I did stand (I'm a big guy) on the rear bumper (left, center, and right) and crazy flexed the rear suspension. I could not get it to make a sound. I'm leaning back to the brakes. grrrr.... bleh.

 

[Nad_Yvalhosert]

You have 2 noises that are happening simultaneously. My buddy's old '98 Tahoe made those noises. His would honk like a horn when you'd accelerate.

First, the squeak pads between the leaves were worn through and the leaves were metal to metal. Replace them.

Second, you have glazed surfaces on the brake drums. Yank "em off and lightly scuff the friction surfaces with rough sand paper. Shoe and drum.

Lastly, it's not an up/down noise, it's an axle wrap noise.

 

[Roy Martin]

I would deffinitly get it off the ground and check for pinion play.
Only because that is big time pain in the ass if we are all wrong.
But, I dont think thats the problem.
Do you still have cats on that?
If so, bop em a few times with a rubber mallet to see if the element has come loose inside.
Same with the muffler
Hard to tell over a cell phone but that seems to be a loose hollow tin rattle sound rather than the "thunk" I would expect from a pinion.
Plus, I dont think you would have a pinion anymore.

The exhaust is new behind the cats, which are new-ish (last 2 years). I can check, though. I maintained the dual pipes and cats to dual-in, big single out muffler, and installed the Magnaflow catback designed for this application. Here's the link:

MagnaFlow Street Series Cat-Back Performance Exhaust System

 

[thinger2]

Always assume the worst first.
Check the big money stuff just so you can scratch it of the list.
Basic diagnosis is
1) **** that might blow up and cost a bunch of cash and leave me stranded.
2) **** that might get me home but cost a bunch of cash.
3) 450 dollar tow truck
4) **** I can do in the driveway once I get home.
Even if your transmission blew into a thousand pieces and shredded the diff while breaking all of the rods.
It is all still pretty simple stuff.
The only thing more basic than a small block chevy is an air cooled volkswagen.
Dont go vw, you will have to grow a beard.
Your wife will have to grow a beard.
Your children, if you can get close enough,
Will be born with beards.
Amd maybe a spare random toe
To me, over the phone, it just doesnt sound like a pinion thump, clang noise

 

[Roy Martin]

You have 2 noises that are happening simultaneously. My buddy's old '98 Tahoe made those noises. His would sound like a horn when you'd accelerate.

First, the squeak pads between the leaves were through and the leaves were metal to metal. Replace them.

Second, you have glazed surfaces on the brake drums. Yank "em off and lightly scuff the friction surfaces with rough sand paper. Shoe and drum.

Lastly, it's not an up/down noise, it's an axle wrap noise.

You're absolutely right on not up and down. I like these ideas. My dad (they had it for about 12 years after my grandfather died) cannot confirm if the drums have ever been replaced, so I may retire them. Depends on what I find when I take them off. Now squeak pads - are these separate parts or are they integrated into the leaf springs? Making sure I understand completely what you are suggesting. Thanks.

 

[Nad_Yvalhosert]

They are a plastic wafer that has a "post" that goes into the locating hole in the end of each individual leaf.
You'll need to lift the truck by the frame, dangle the axle, release the leaf clip bolts, and pry/spread open each leaf about 3/4 of an inch to insert each one.

 

[thinger2]

You're absolutely right on not up and down. I like these ideas. My dad (they had it for about 12 years after my grandfather died) cannot confirm if the drums have ever been replaced, so I may retire them. Depends on what I find when I take them off. Now squeak pads - are these separate parts or are they integrated into the leaf springs? Making sure I understand completely what you are suggesting. Thanks.

Im liking these ideas. It does sound like a load/ unload noise.
Try a can a spray grease and just hose the springs and bushings and hangers and see if the noise changes.
I still dont think its Pinion

 

[sewlow]

Im liking these ideas. It does sound like a load/ unload noise.
Try a can a spray grease and just hose the springs and bushings and hangers and see if the noise changes.
I still dont think its Pinion

I don't think it's pinion related, either.
What kind of shape are the U-bolts & lower plates in? A notorious 400 problem area.
U-joints good? I would think that those would of been one of the first things checked.
Leaf spring centering bolts still there? They haven't broken or just turned to dust? It happens.
How's the body mounts?
Tried rocking the vehicle not just up-n-down, but side-to-side?

Spraying some lube is a good idea. If you have the patience, just spray one element at a time, sayyy...every second day. This'll make it easier to narrow down the exact problem.
I'd start with the lower shackle bolts/bushings. Just one at a time. Followed by the uppers, then move to the front hangars. Upper/lower shock bushings, etc. etc.

 

[Bu327]

I need to replace my “squeak pads” also, are they available by themselves? The leaves aren’t making any noise but I can feel them not moving smoothly. My rear u-joint is starting to clang going from fwd to rev.

 

[Schurkey]

My rear u-joint is starting to clang going from fwd to rev.

When that was my truck, I replaced the sloppy, worn-out 8.5 axle. The pinion had way too much rotational play, might have been the ring and pinion mesh, or it may have been sloppy side gears and axle shaft splines. I traded that axle for a used dorm fridge.