Clunk only when turning left, 2001 silverado 4x4.

as i have said in other post i am a licensed auto tech in canada. this is my own personally truck that i'm working on a few different things. i'm getting a pretty loud clunk when i turn left almost 90 degrees, like from one road onto another. i've checked the front end numerous times, so have other techs where i work trying to figure this out. both lifted up and with weight on the wheels. last year shortly after i got the truck i had the same type of noise when turning either way, i found a bad left upper balljoint and what i thought was bad bushing on the upper control arm which turned out to be a broken adjust bolt and had worn through. so i put a new upper control arm w/ balljoint and new adjuster bolts. found nothing else in the front end bad. again previous owner had done a wheel bearing and tierod on the right side. everything seemed fine until about january, truck had been sitting for about a month while i was off work injured and i think that was when the -40 cold spell hit, that i mention in my other post. anyway i rechecked that the adjuster bolts were tight and the balljoints were all good, etc. i've been trying to search if anyone else has a similar issue, but all i find is steering shaft clunk and bushing creak and obvious bad balljoints, tierods, etc. i did watch one vid on youtube that points to a possible bad cv, but it only clunks loud once when turning left sharply. and the cv seems tight. this is driving me nuts. every time i check it, i look for any little thing. someone said maybe the bushing in the control arm that the shock bolts through, but it doesn't turn, or possible torsion bar mount bushing on the frame, but the noise is not back under the cab, its in the left front wheel area.

The steering shaft clunk is definitely an issue with GM's. I had the same issue in my Grand Prix years back. It took me awhile to find the issue. I was thinking it was the strut mounts popping because the whole car would "pop" when I turned the wheel. I'd honestly try that before you go pulling your hair out trying to figure out other issues.

I've had struts do the same thing, even walking the coil spring around from a completely frozen upper mount. But as you know, the '01 Silvo 4WD is not strut-equipped, and uses torsion bars in lieu of coils.

Since you are in service, you may have alignment turntables available. You might want to consider using those to see if the noise repeats in static testing with load on the front axle. You can load a side at a time by raising the opposite side using a floor jack under the LCA. If you determine the noise is only happening dynamically, you might want to look back at the axles/CVs and the front axle itself.

The steering shaft clunk is definitely an issue with GM's. I had the same issue in my Grand Prix years back. It took me awhile to find the issue. I was thinking it was the strut mounts popping because the whole car would "pop" when I turned the wheel. I'd honestly try that before you go pulling your hair out trying to figure out other issues.

i know all about the steering shaft clunk, but in my experience its most noticeable driving straight and not always over bumps, but always seems to constantly rattle. i've done hundreds of these. i had this issue with this truck already, put a new updated shaft in it all ready and the steering shaft rattle is gone. now i guess that doesn't guarantee that its not related or that one of the little ujoints on the steering shaft isn't bad, but its really loud in the left front, so i'm leaning somewhere else but still keeping it in mind.

I've had struts do the same thing, even walking the coil spring around from a completely frozen upper mount. But as you know, the '01 Silvo 4WD is not strut-equipped, and uses torsion bars in lieu of coils.

Since you are in service, you may have alignment turntables available. You might want to consider using those to see if the noise repeats in static testing with load on the front axle. You can load a side at a time by raising the opposite side using a floor jack under the LCA. If you determine the noise is only happening dynamically, you might want to look back at the axles/CVs and the front axle itself.

i've experience that strut thing before, so i am familar with that, but your right the truck doesn't use struts. i put '01 in the title, this is actually my '02, i've been working on so many early '00s trucks lately that sometimes they run together.
using the tables is not a bad idea, i was actually just thinking of trying to turn it on the ground but this may be easier. i've been thinking about the axles and front diff, i was thinking about swapping a cv from my '03 to see if anything changes, its down for a fuel pump and fuel lines, not sure if i will fix it, as it has over 300k and the body is gone on it.

my front diff is leaking some where the right axle tube bolts on and the right axle seal is leaking, but i've never let it run low on oil. Don't have another diff with the same ratio to swap and try that. ans i really hate throwing parts at something on a guess, i would rather be sure first.