I *CANNOT* Find My Rattles!

[l008com]

In 2015, I got rid of my 1998 ZR2 Blazer (not a primary vehicle) and replaced it with this 2008 Trailblazer (my primary vehicle). The difference in the way it drove and handled was dramatic. Especially how quiet and tight everything was. Driving the old Blazer was like driving a car with a bunch of metal 5 gallon buckets full of rocks and nails and old tools. Every bump sounded like the end of the world. But in the trailblazer, it would take bumps like a car.

But times have changed. I've been getting louder and louder rattles lately and it's really starting to drive me crazy. I did have loose heat shield issues above my exhaust but I fixed that (in another post). I thought - hoped - that was going to be most of the problem but it wasn't. I still get very loud clunks and rattles when hitting various kinds of bumps. It doesn't SEEM like it's body-related, it all seems like it's coming from underneath.

But I've been under there tons of times. Sometimes specifically to hunt down this noise. And nothing. Everything I can find under there is super tight. Nothing moves, nothing rattles. I've had it up on jack stands, up on lifts. Even just rocking it as hard as I can on flat ground... no luck. I've gone through all storage compartments to make sure I wasn't just hearing my own junk bouncing around. I'm not sure what to do next. It sounds OBVIOUS. Meaning the sound it makes when hitting certain bumps sounds like the kind of thing you'd easily be able to find. It sounds like something VERY loose is moving around.

Any suggestions for things I can do, specific things to check, or some other way? I wish I could get under there while driving and try to hear where its coming from. I've had other people drive while I move around the cabin trying to listen from inside but I just can't tell. And its not like I'm actually going to try to get under a moving vehicle. I'm not crazy. But these rattles are getting me there!

Picture added for no particular reason. The mud is from driving around in a quarry dumping old concrete and asphalt.

 

[Sparky]

Did you try the end links? They can make quite the racket. If you can twist them side to side on their ball sockets easily when under the vehicle, they're likely shot. Mine was sounding like a tin can and it was those.

And if you replace them, be prepared to cut them off, and make sure you crank the new ones down tighter than superman.

 

[l008com]

Are you talking about front links or rear links or both?

All my links are new.... well I guess they're not new anymore but they're new to me. Stiffer 'performance' ish links I bought a bunch of years ago. And I have wiggled them around and they do all feel pretty tight.

I don't remember the details of the first time I replaced them, but looking on rockauto right now and these things are dirt cheap. $2.85 for high performance front links? Might as well replace them just in case. Rears are a little more and they only have "regular" ones on the site, $20 each. Still not terrible at all.

I don't believe I had to cut off the original ones a few years ago. Hopefully I don't have to cut these. But I do have a wide variety if impact guns, breaker bars and saws if need be

But thinking about this, is there a way I can confirm it's the links? Is there a way I can put the right amount of pressure that will cause them to rattle for me in a test?

 

[Mooseman]

with @Sparky . Check all of them. Also check the sway bar bushings.

Also check your suspension pieces and do the "hit with your hand" on the exhaust with a check of the hangers.

 

[l008com]

Exhaust and hangers all seem fine

 

[TequilaWarrior]

As mentioned above, check swaybar end links and bushings - both front and rear. Even the slightest gap in a bushing will present a rattle. Check your spare tire lift/carrier. If it's loose it may present a rattle. "Shake" each door, if anything falls into the bottom of the door it will rattle like heck. Check the center console (remove the insert), and remove the glove compartment and look behind it for the same reason. If something gets in there it will rattle like hell. I've found sockets inside the dash, bolts inside of door shells, all sorts of oddball things causing rattles. Also, ensure the bolts securing the UCA and LCA to the bracket or frame are tight to spec. If they're loose at all, they can cause a pretty good rattle.

 

[Sparky]

"A Bunch of years ago" - I only ever got a couple years before they made noise again. Crappy boogers they are.

 

[jc1]

I was chasing a rattling noise in my 2008 Trailblazer for months. It ended up being the bushing on the brake pedal pivot. I replaced it and the noise is gone. The bushing is still available.

 

[l008com]

I was chasing a rattling noise in my 2008 Trailblazer for months. It ended up being the bushing on the brake pedal pivot. I replaced it and the noise is gone. The bushing is still available.

HAH i had this problem years ago. Everything was still tight so there was no rattling at all. Then suddenly it started clunking on large bumps. I had no idea what it was until one day I was driving barefoot and had my toe just barely on the pedal and i was able to stop the noise. I just tightened it up and its been good since.

 

[Chickenhawk]

I agree with the suggestions on sway bar links. It is hard to diagnose just by feel, but they can be a major cause of rattles when hitting bumps. They also need to be VERY tight when installed.

Also, when the engine is cold, crawl underneath and hit the cat converter with your fist. It may be broken baffles inside and these can cause serious rattles. Not likely, but worth the five seconds to find out.

 

[l008com]

I have checked all the links when these sounds first started happening and they all seemed tight. But the sounds are definitely worse now and when I just went out to check my end links, this is what I got:

I'm assuming that's pretty definitive that at least some of my rattles are the links?

If so, I'm going to replace the links again but I need a little help picking them. I'm going to do front and rear because I might as well. Here's the options from rockauto:

2008 CHEVROLET TRAILBLAZER 5.3L V8 Sway Bar Link | RockAuto

RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.

www.rockauto.com

Regarding Front Links:
I'm not fully sure how to make sense of the categories. I mean economy is cheap, what is daily driver? Heavy duty vs high performance? Plus the high performance links are $2.85 which seems weird. I do want ones as stiff as possible if that's an option. Aside from the $2.85 option (FVP SK6629), I'm thinking the Dorman SL91065RD $12.25 option would be good. But I don't really know how to judge the quality/performance of these different options.

Regarding Rear Links:
The rear links seem a little easier to gauge. They have AC Delco links for $29 each, but the "premium" Dorman links are $17 each. So I'm thinking I should just get the Dorman premiums?

 

[Mooseman]

I recently bought an outer tie rod from Dorman and it looks quite good. And looking at the pics of the links, Dorman's look like the originals, which honestly, lasted the longest. I still have my originals at 140k km. I'd go with those.

Whatever you choose, stay away from Mevojunk, all of them, including their TTX line. The ACDelcos look suspiciously like them.

 

[l008com]

They must have heard me talking about buying, the right rear has gone up $2 since my last post

I think my front wheel bearings are mevotech heavy duty hubs. Again, "whatever heavy duty means". I just rolled the dice and hoped that means they'll last longer. They've been ok, no complaints. My only complaint is that I wish I had done the repair myself the previous 4 times. Its super easy and would have saved me a lot of money, but I'm getting WAYYYY off topic.

I guess once I get these plugs and wires installed, i'll order up these new links. I don't know how many of my rattles and clunks that will fix but it sure would be nice if it fixed them all

 

[l008com]

While I was working on my spark plugs today, I felt around the front links. One of those was pretty loose too. Guess it's time. As soon as all the link are available in the same shipping warehouse, I'll order them up. Replacing those will be cake compared to what I went through changing my plugs today

 

[Sparky]

While I was working on my spark plugs today, I felt around the front links. One of those was pretty loose too. Guess it's time. As soon as all the link are available in the same shipping warehouse, I'll order them up. Replacing those will be cake compared to what I went through changing my plugs today

That's what you think!!!

 

[l008com]

Thats what someone else said but I replaced them before and I don't remember having any trouble. I replaced them, and the rear swaybar and all swaybar bushings all at once, without an impact wrench, all hand cranking tools. Doing just the links, I don't even have to take the wheels off or jack it up, I can roll up ramps. I dunno I think it's going to be easy. I hope I'm right.

 

[TequilaWarrior]

Thats what someone else said but I replaced them before and I don't remember having any trouble. I replaced them, and the rear swaybar and all swaybar bushings all at once, without an impact wrench, all hand cranking tools. Doing just the links, I don't even have to take the wheels off or jack it up, I can roll up ramps. I dunno I think it's going to be easy. I hope I'm right.

It's a crapshoot. I've had the "this couldn't have gone any better" experience changing links on my Brravada once (10, maybe 15 minutes per corner, tops!).... but the last time it took a sawzall, an air-powered cut-off, hammers, etc.... and was one of the worst experiences I've ever had. If the mounting bolt spins within the link, "you're not gonna have a good time"....

 

[l008com]

Well hopefully it works out. I have an angle grinder if need be. I'm still waiting for the right warehouses to have the right links in stock on rockauto so I haven't ordered them yet. I have a few more questions but I'll probably wait till I'm ready to go so everything will be fresh.

 

[l008com]

New links have shipped!

Ok questions:
The issue with the rears seems to be that they might break loose internally so you can't unscrew them. So question 1 is, is that any MORE or LESS likely to happen if I use a breaker bar, or an impact wrench, to unbolt them?

When putting the new ones back on, I don't have a torque wrench, how tight should I crank these down. Just barely tight, good and tight, as tight as I am physically capable of?

 

[Sparky]

In my experience, you crank on them as hard as you can, which is one reason why I like the aftermarkets that have a hex to hold the shaft with instead of the stupid allen wrench as I can get a lot more leverage on them.

 

[TequilaWarrior]

New links have shipped!

Ok questions:
The issue with the rears seems to be that they might break loose internally so you can't unscrew them. So question 1 is, is that any MORE or LESS likely to happen if I use a breaker bar, or an impact wrench, to unbolt them?

When putting the new ones back on, I don't have a torque wrench, how tight should I crank these down. Just barely tight, good and tight, as tight as I am physically capable of?

If the links spin, sometimes you can get them to grab just enough with vice-grips; but, this is one of those jobs you're well served by keeping a hacksaw, sawzall, cut-off, or grinder on standby. A couple of xanax and a quart of Jack Daniel's wouldn't hurt either....

 

[l008com]

Ok another project completed! I got all the new links on. I *think* it's handling a little better, but that might all be in my head. But the rattling has definitely stopped. I've been chasing this rattle for years. I didn't think it was the links because, well for one thing the links always felt tight when I wiggled them. But also it started pretty soon after I installed these links. It's been getting very slowly worse for many years. But I drove around some very bumpy roads aka roads (MA) and I still have a very subtle interior body panel type squeak but other than that, the truck is pretty damn quiet!

But one thing that made me real sad.... so much rust underneath! I had to sweep the driveway when i was done. The amount of rust makes me fear this truck might not have that much time left. Which granted I've been saying for years but after replacing the plugs, I had changed my mind

Anyway heres the long story:

The fronts came right off.... in that they fairly easily snapped when I tried to unbolt them. Both sides. The new ones went on nice and easy.

The rears, oh the rears. Breaker bar, impact gun, it's all the same. It seems like the ball is fully free-floating, which is the case for the new ones. I tried to grab the inner square counter-nut thing so I could have something to hold steady against and get the nuts un-screwing. Total fail. In fact, trying to unbolt them moved that square nut anyway and actually stripped the teeth out of my vice grip. It was crazy. So I ended up having to grind them off with an angle grinder and a little bit of dremel.

One popped off pretty easy, the other three were a pain in the ass. And reinstalling the new links, the one on the gas tank side was a real pain in the ass. I could only get one ratchet click worth of movement on my socket so i was cranking away for like 5 minutes to install one bolt. Very annoying. But in the end, it all worked. This truck is driving excellent right now. It makes me want to go back to my long-abandoned headlight upgrade project . . .

Also I did the fronts using ramps, without taking the wheels off. I tried to do the same with the rear. And if I had been able to unscrew the bolts, that would have worked. But once they started spinning, I had to jack the truck up, but it on jack stands, take the wheels off, and fire up the angle grinder.

All said and done, i DO think this was still easier than doing the plugs and wires. At least I could LOOK at the parts I was working on today, I wasn't forced to do everything by feel