Rear Shock Mount Fell Out

[BenThere]

Just a heads up from the "For What It's Worth Department"

 

Started hearing something coming from the back when I went through deep dips and especially going over those speed control bumps in parking lots, like some loose pipe or 2X4's were bouncing around in the bed; and the back end was a little "bouncy".  Nothing in the bed, so I crawled under and noticed the top right shock mount bolt was gone, and the top of the shock was whacking the mount, frame, and underside of the bed.  I have a dealer-installed factory 2" Rancho Iift on my 2019 Z71 Silverado.  

 

Took it in to the dealer, and while it was on the rack I talked with the suspension technician guys.  One of the techs said he'd seen 5-6 of these, on stock suspensions and a Trail Boss, always the top right shock mount.  Like, it's a "thing" with these trucks.

 

So, just letting y"all know that you might want to keep an eye on yours, maybe crawl under and take a look every once in a while.  Maybe even the next time you have it in the air for something like an oil change or something, put a wrench on the bolt(s) or even pull it out quick and put it back with some locktite.  

 

[Doolin-Dalton]

Thanks, wondering - how many miles on your truck?

[Silverado4x4]

Sounds like a dealer install screw up and by him saying he seen 5-6 of these is nothing but a lie so you wouldn't get pissed at them for not properly torqueing the bolt or not tighten at all. Those bolts don't just fall out.

[Weaverstreet]

I replaced my stock rear shocks with some Rancho 9000 adjustables (which are great)  and had this same thing happen. Weeks later I lost the left side top screw and had to get one from the hardware store. I really did tightened them plenty tight . I also found that the right side top screw was loose. I when removed it and noticed that the threads seemed too easy to remove by hand. I used some locktight red on top and bottom of both shocks and it's been fine for a couple of months now. 

[davester]

So the mount didn't come out, just the bolt.  I think a better recommendation would be for check that they are torqued properly.  this is a dealer screwup, and given that dealer admitted to you that it happened 5-6 times there, I would suggest going to another dealer for any further work on your truck...

 

I know when I replaced the shocks with RS9000's on my truck, I torqued them down to spec, and haven't had a problem with them since (about 50k miles ago).

Edited October 12, 2019 by davester

[steveved]

Locktite helps...

[BenThere]

19 hours ago, BobbyAlton said:

Thanks, wondering - how many miles on your truck?

Almost 10K.  Includes some semi-serious off road in Utah, Colorado, and Arizona.  

[BenThere]

15 hours ago, davester said:

So the mount didn't come out, just the bolt.  I think a better recommendation would be for check that they are torqued properly.  this is a dealer screwup, and given that dealer admitted to you that it happened 5-6 times there, I would suggest going to another dealer for any further work on your truck...

 

I know when I replaced the shocks with RS9000's on my truck, I torqued them down to spec, and haven't had a problem with them since (about 50k miles ago).

I don't think this was a dealer screw-up; although that was, of course, my first thought.  But I've gotten to know the suspension tech that did the work on the suspension pretty well, and he's very thorough and meticulous.  He takes a lot of pride in his work, and was very embarrassed/concerned that it might have been his bad.  I watched him re-torque everything else he did and the rest checked out just fine.  

 

It was one of the other techs there that said he'd seen 5-6 other instances of this happening even on stock trucks. Take it for what it's worth.  

 

I think I did suggest in my OP that others reading this thread to  "put a wrench on the bolt(s) or even pull it out quick and put it back with some locktite."  

 

And, yeah, I can go to another dealer for future work, but who knows what you'll get there?  And, things are different these days than maybe 5 years ago; getting another dealer to work on your truck that you didn't but from them can be problematic on a few different levels.  They can be real pr'ks...... Ask me how I know....... 

[FiatDale]

This happened twice on my lofted 2010 and once on my fathers 16 which was bone stock. Same bolt. Don’t know how or why

[CadillacLuke24]

Glad it didn't hurt anything. Sounds like an odd occurrence more than anything. People aren't perfect, but based on your description of the tech it doesn't sound like lackluster work. 

[Nanotech Environmental]

This isn't a new thing. Same thing would happen on my old '84 GMC Fullsize 4x4. Always the right side upper shock bolt would get loose. 
I ended up welding extra support on the frame & making many improvements so that it would stay put.

[HondaHawkGT]

On 10/12/2019 at 4:19 PM, BenThere said:

I don't think this was a dealer screw-up; although that was, of course, my first thought.  But I've gotten to know the suspension tech that did the work on the suspension pretty well, and he's very thorough and meticulous.  He takes a lot of pride in his work, and was very embarrassed/concerned that it might have been his bad.  I watched him re-torque everything else he did and the rest checked out just fine.  

 

It was one of the other techs there that said he'd seen 5-6 other instances of this happening even on stock trucks. Take it for what it's worth.  

 

I think I did suggest in my OP that others reading this thread to  "put a wrench on the bolt(s) or even pull it out quick and put it back with some locktite."  

 

And, yeah, I can go to another dealer for future work, but who knows what you'll get there?  And, things are different these days than maybe 5 years ago; getting another dealer to work on your truck that you didn't but from them can be problematic on a few different levels.  They can be real pr'ks...... Ask me how I know....... 

 

There is absolutely NO reason for a bolt to fall out if it's properly torqued. That's the purpose of providing torque specs for fasteners... so they don't loosen up. Any tech that says such things is covering their own ass by saying it's a common issue. Yeah, it's common... if you don't use a torque wrench or re-use TTY single-use bolts.

Edited October 14, 2019 by HondaHawkGT

[Grumpy Bear]

18 minutes ago, HondaHawkGT said:

 

There is absolutely NO reason for a bolt to fall out if it's properly torqued. That's the purpose of providing torque specs for fasteners... so they don't loosen up. Any tech that says such things is covering their own ass by saying it's a common issue. Yeah, it's common... if you don't use a torque wrench or re-use TTY single-use bolts.

NAILED IT! 

[BenThere]

17 hours ago, HondaHawkGT said:

 

There is absolutely NO reason for a bolt to fall out if it's properly torqued. That's the purpose of providing torque specs for fasteners... so they don't loosen up. Any tech that says such things is covering their own ass by saying it's a common issue. Yeah, it's common... if you don't use a torque wrench or re-use TTY single-use bolts.

Why not?  Suppose the sleeve inside the shock mount bushing tends to compress or wear just enough that the tension on the bolt is reduced?   What if there's some super funky harmonic that develops in that particular location that backs the bolt out?  Maybe, since the bolt is not shouldered, it's fully threaded, that the interaction between it and the inside of the sleeve creates a dynamic that loosens the bolt (you can see the marks of the threads inside the sleeve in the photo).  Maybe a combination of all of those factors?  Danged if I know.  Are you telling me that you've never, ever, in your whole life, ever had a properly torqued fastener back off?  Like, ever?  I sure have.....  And, somehow I doubt that a TTY bolt is used on a shock mount......

Anyway, here's the deal: as I said earlier,  take it for what it's worth.  I'm just passing along my anecdotal experiences FYI.  Readers of the thread can check the bolt on their truck, they can even back it out and put some locktite on it just in case, it's easy to do.  Or not.  It's a lot easier in the driveway to find and check the bolt than it is on Black Bear Pass. 

 

YMMV....

[Nanotech Environmental]

21 hours ago, HondaHawkGT said:

 

There is absolutely NO reason for a bolt to fall out if it's properly torqued. That's the purpose of providing torque specs for fasteners... so they don't loosen up. Any tech that says such things is covering their own ass by saying it's a common issue. Yeah, it's common... if you don't use a torque wrench or re-use TTY single-use bolts.

Actually, there's about a 1000 reasons. If what you said is true, things like loctite, special lock washers, safety wire and locking nuts wouldn't exist.
Rear shock bolts on pickups are especially susceptible to backing out, or getting loose, even when correctly torqued.  The best fix is to use additional methods to secure them.