Can't find a source of front suspension noise

[FLJoe]

I have a 96 4WD Tahoe with a stock suspension. I get a bumping/light clunking sound these days when in a tight turn and going over a bump, generally at parking lot speed. It's about the same turning left or right. For the life of me I can't find anything loose under there.

I just had a mechanic replace the pitman and idler arms, along with the tie rod ends. The four ball joints and all control arm bushings are about 85,000 miles old, and the guy that did the steering work just now said they all seemed good. The torsion bar mount links are also about that old and look good to my eyes. The stabilizer bar end links and bushings are about 50K old and look fine.

Basically, everything I can think to check looks fine and/or is new, the truck feels normal and drives just right in normal driving, I just can't find what's bumping/loose that I'm hearing when I turn and hit bumps. Any thoughts are greatly appreciated.
Joe

 

[HotWheelsBurban]

I have a 96 4WD Tahoe with a stock suspension. I get a bumping/light clunking sound these days when in a tight turn and going over a bump, generally at parking lot speed. It's about the same turning left or right. For the life of me I can't find anything loose under there.

I just had a mechanic replace the pitman and idler arms, along with the tie rod ends. The four ball joints and all control arm bushings are about 85,000 miles old, and the guy that did the steering work just now said they all seemed good. The torsion bar mount links are also about that old and look good to my eyes. The stabilizer bar end links and bushings are about 50K old and look fine.

Basically, everything I can think to check looks fine and/or is new, the truck feels normal and drives just right in normal driving, I just can't find what's bumping/loose that I'm hearing when I turn and hit bumps. Any thoughts are greatly appreciated.
Joe

Just going on the basis of the sound, that sounds like control arm bushings or ball joints. But my experience is with 2wd vehicles.... control arm bushings also usually creak when they go bad.

 

[SomeTahoe]

Sounds like you are chasing down noise from your CV joint(s). Mine are about done but I have put off replacing them since I won't need 4wd for a few months still, and I get very similar symptoms to what you are describing.

 

[Schurkey]

Exhaust system swinging into contact with the floorpan or something?

Loose heat-shield?

Loose park-brake cable(s)?

 

[GoToGuy]

I had a slight clunk noise not real loud but enough at less than 25 with window open could hear it. Narrow down to left side front.
Had my son jump up and down on Left front corner of bumper. Touch feel all joints moving connections, found front upper left shock mount had 1/4 inch play. Take apart add some washers to fill gap. Test drive no more noise. Just one of many " could be, how I found and fixed". Good luck.

 

[FLJoe]

Thanks for the replies and thoughts.

It's possibly the CV joints, but I'm not sure. The have a couple hundred thousand miles on them, but nearly all of it is under no load in 2WD. I used to use 4WD all the time when the truck was up in the Western NY snowbelt, but since those axles went in, about the only time I use 4WD is an occasional sandy dirt road or pulling the boat up the ramp. When I spin them I can feel a slight play in all the joints- each joint really doesn't have a visible amount of play, but if I grab the flange at the differential I can see maybe a millimeter of rotational play in the whole axle assembly.

I've also checked the front wheel bearings. I'm a little suspicious of those. They spin nice and smooth, but there is more side to side play than I would have expected at the tire. If I grab a tire and push it in and out at the top I can get about 1-2mm of play. I always expect wheel bearings to have a little play (they should generally) but I'm wondering if that's a little excessive. Still, it doesn't seem like anything that would make a bumping or clunking sound...

The exhaust seems tight and didn't seem to be bumping anything (good thought), but it's possibly a bad set of motor mounts or transmission mount allowing things to move too much? The shocks seem tight.

I guess I'll have to do a lot more jumping and pulling on the truck with it parked to see if I can isolate the sound.

 

[RichLo]

I just found the cause to a similar sound on my winter beater blazer. It was a front cab body mount that was rusted and clicking. Because it was a long roof it didnt show any sag like trucks do when body mounts go bad. But since your in FL its probably not rusted but worth a check if your under there.

 

[FLJoe]

Body mount is a great thought. I've been in Florida for 15 years with the truck, but the first 12 years of its life were in the worst part of the salt belt in Western NY. I've had to do a lot of rust repair on it, including welding in new rear body mounts where the sheetmetal had given out. I've stripped and painted all the frame and suspension components over the years and the bottom is pretty clean now, but it does still have some residual damage from those years up north.

 

[95burban]

Are the bars cranked? If so maybe upper control arms bottoming out.

 

[FLJoe]

The bars have been out. When we put everything back together, the driver side bar needed quite a bit more cranking than the passenger side to get a level ride (I think it's just sagged after a half million miles). That one's bolt is probably 3/4 the way in, while the passenger side is a little over half.

At this point it may be sitting about a half inch higher than normal in the front, I really can't say for sure, but it's definitely not cranked to near full extension. Having said that, the rubber bump stops are long gone... I'll see if it looks like they may be bottoming. It's a good thought.