How do I know OEM shocks for 2011 GMC Sierra 4x4?

[Jworks]

2011 Sierra 4x4, 5.3 engine.  I bought it from a dealer with 95k miles.  Now has 141000 miles.  I have a loud "rubbing" or squeaking sound underneath the rear.  I hear it when going slowly over uneven ground in my yard, or other places where the ground is uneven, and moving at a slow pace.  It sounds like its on the right side.  T I can stand on the nerf bars or go to the back of the truck and rock it and hear it plainly.  I thought maybe it was the rubber grommets on the shocks so I got under the truck and sprayed them with white lithium grease.  Its still there.  There is no leak in the shocks, they look good just based on my observance.  My "guess" is they are original shocks.  Any ideas?

[bubbanbrenda]

If they are the factory shocks they’re probably worn out based on the age and mileage, if you or the previous owner did any towing they’re definitely worn out. Spraying white lithium grease on the bushings won’t quite the squeak if that’s why you’re hearing, you’re going to get the grease inside the bushings where the parts are rubbing. I would replace them and go from there.

[Jworks]

bubbanbrenda, I know what you mean.  I just hate to buy shocks not knowing for sure that is the reason.  You can bounce it up and down with your body weight but its not real easy to do, and when you stop it does not keep bouncing.  I'd think if the shock was bad it would not be stopping immediately like it does.  I am now thinking it may be the front leaf spring bushing.  I got back under there again since I posted this and sprayed the shock bushings with WD40 (thinking that was thinner and would probably seep  in quicker - just to see what happens).  I rocked it up and down best I could from underneath the truck (as its just me here and no one else) and I could still here it.  Still squeaked.  I decided to hold onto the leaf spring and lift up and down best I could with the other hand to see if I could feel anything.  When the squeak occurred the hand holding the spring could feel it through the metal as it squeaked.  That made me think it may be the leaf spring bushing.  I doused it pretty good with WD40 for the same reason mentioned above.  Squeak was still there but a lot less.  An hour later I drove it a while and then over some uneven ground.  I couldn't hear it all.   I just checked it again in the driveway.  No squeak, its gone.  With WD40 it will likely come back.  We'll see I guess.  If it does, I'm wondering is there anything I can do that would be more permanent.  I have some wheel bearing grease - both the black synthetic kind and a blue boat trailer bearing grease. 

 

By the way, yes I have pulled a 18 ft. fiberglass boat (about 1800 lbs total) about 4 times to the gulf, 360 miles one way.

 

 

 

 

Edited June 12, 2022 by Jworks

[dsr611]

Read this

 

[Jworks]

UPDATE:  10 days later after dousing the leaf spring bushing with WD40.  No more squeaks.

Edited June 22, 2022 by Jworks

[Jworks]

On 6/12/2022 at 4:32 PM, dsr611 said:

Read this

 

dsr611, thanks.  I read it, it was dated 2012.  Lucky he got right on it and GM helped him out.  So far (18 days later) the squeak has not returned.  Being that the WD40 sure stopped it in my case I won't be surprised if it comes back.  If it does I'll douse it again.  I do NOT want to think about replacing leaf springs and possibly go through that axle and alignment issue he did.  No chance that GM would make it good, my truck being 11 years old.  Geesh.

[Jworks]

Update:  One month after I used WD40 on the front leaf spring bushing the groaning sound returned.  Can't buy just the bushing and replace it.  You have to buy the whole leaf spring.  And they say you have to buy both sides; if you tried doing one side you'd end up with the bed not being level.  $900 at a dealer; $700 at an independent shop.  So, I'm trying silicone spray; will let that sit overnight.  If that is no good I'll do the WD40 for now.  Otherwise, I'll just live with it for now.

[swathdiver]

On 7/6/2022 at 6:20 PM, Jworks said:

...And they say you have to buy both sides;

 

They is wrong!

 

45E1243 or 19365869 for the leaf spring bushings, 45E1242 or 19365867 for the shackle bushings.

[Grumpy Bear]

Tis the front bush. Mine has done it since day one but usually only on wet or really damp days. Been doing it for its entire life. The truck has Deaver springs and we reused the OEM bushings as they were new when the springs were replaced. Greased the snot out of them with wheel bearing grease. Still squeaks. Truck now has 155K on it and solid as a rock and just as noisy. 

 

Energy suspension has urethane bushings and a 'special' grease that is suppose to fix it. Maybe someday.