No TPMS and no tube. All my rims balance out even. No dents.

I've been through a huge tire saga over the past summer with balance when my local Pep Boys added 4.5 oz of weight to the outside and an additional 3 oz of weight to the inside of one wheel.
I brought it back to that shop like 8 different times after feeling an imbalance shaking that comes and goes while driving.

They told me that "the wheels are technically balanced according to our computer, so I don't know what else you want from us" they say while slapping 8oz of weight on them.
One guy at a different family owned shop told me that all they counter-balanced my wheels, and that no amount of balancing would make them ride smooth.

I noticed that things tend to change or move around if I'm going around a long bend on the highway. Things are fine and super smooth on one stretch, but then I turn slightly towards the left going around a bend, and then coming out of it I feel a kind of shaking that makes me think something is unbalanced.

It has really boggled my mind. One wheel is doing just fine with a single 1oz clip-on weight on the inside, but I have another with a combination of clip-on weights and stick-on weights applied almost all the way around. They had even stacked the stick-on weights at one point.

These weights are not currently on there. This was from a while ago and I made them fix it.
https://cimg8.ibsrv.net/gimg/blazerf...8e8d80f76b.png

So the idler arm replacement is what made a big diference, but I'll answer this questions anyway in hope to further improve everything.

It's not RPM dependent. I've testing this numerous times crusing at 70 MPH in neutral and drivng up to 20 MPH in first gear hitting 3K RPM.
It is speed dependent but it doesn't always happen at a specific speed. Always above 50 MPH and sometimes gets worse the faster you go.
There appears to be a sweet spot, but that's been very difficult to identify. It always comes and goes after going around slight curves with various road conditions.
It will sometimes come or go after coming out of stop-and-go highway traffic.
Front wheel bearings are new. Have about 15K miles on them.

So I do have an issue with my CV joints where they are leaking grease. It splatters all over the control arms. I removed both axles when I was rebuilding the front suspension and repacked them with grease. The shaking is what prompted me to rebuild the suspension in the first place, and it did absolutely need it.
When I pulled the axles out, the dirver side was missing it's clamp, and the other side was barely hanging on. I replaced both clamps and packed them with new grease.
Since then that grease has continued to leak out regardles of how tight I have that clamp. One of the new clamps has popped off since then too and I need to replace it.

https://cimg3.ibsrv.net/gimg/blazerf...2aebd93268.png

I have this problem as well.

I have a 2.5 lift on mine, with slight crank to go with an add a leaf.

I found that my front diff has a bad bearing where my shot cv axle goes. the mechanic is suppose to be getting my spare diff done shortly, and I have new cv axles going in.

i have narrowed it down to the front passenger side, and the only issue left from my rebuild is the diff and cv axle.

I remember your past threads, but can't remember if you have touched those two parts yet?

Have they ever removed "all" the weights from the rims and done a balancing run on the rims only? I do this, if the balance the machine indicates, exceeds 50 g (1.7 oz). That's to rule out a bad rim. (Marking on the rim with a stencil, where the machine thinks it should balance the rim only. This gives you something to play with, should the tire be out a lot. - Rotating the tire.)

Then I put the tire on, inflate it to, adjust tire pressure to the recommended pressure and back on the balancing machine.
It it runs fine with a max of 2oz I balance.
If it goes over 2oz (each side), and the machine tells me to add where the rim on the first run had the light spot, I rotate the tire by 180 degrees to see what changes. A methodical approach on a piece of paper can help reduce the needed weights quite a bit, or even eliminate the need if it is just little.

Depending on the balancing machine they are able to compute a lot of combinations of weights. Sticky ones on the inside, hammer on on the outside, etc.

BUT! The guy who operates the machine needs to know his machine and how to properly set it up.
I ran into this problem just two weeks ago when doing the wheels on my Alfa Romeo. Small rims, big tires and the sticky stuff simply didn't cut it. Had to hammer on weights on the outside.

Balancing is an art the guy who does it, has to understand. It is all dependent on where you can put the weights. It's simply a "MASS - ARM" thing. And our Blazers with the small rims and big tires are bad for this.

If the machine says do this, and afterwards it says do more and in different spots - something is badly wrong with how the guy goes about it.

I had such an issue once and as I did not trust the guy to have understood his machine, took a pic and looked up the machines manual in the internet to know myself how to set it up. Turned out the guy had it set up for aluminium wheels where the machine wants to stick weights on the inside but added hammer-on weights on the outside. He was chasing balance all around wheel. Looked exactly as yours do.

The only work I've done on those parts was changing the gear oil in the front diff, and repacking the CV axles with new grease.
My current ones have worn out boots, and I'm thinking about replacing the whole axle soon.

Is it possible for the front diff to wear out to the point where it needs to be rebuilt just from everyday use?
I put a lot of highway miles on my Blazer, but I don't take it off-road or abuse it.

I plan to eventually turn it into an off-roading toy once I find another daily driver.

Not sure about the diff.

But for the cv's, if the boots got worn and holes, and dirt or debree got in there, it'll imperfect the ball bearings in there, causing warps and the vibrations.

then it'll lead the bearings on the diff to get worn and deformed.

I recently repacked my CV joints with grease and installed new boots. I made sure the grease was tightly packe in there.
I also greased all my servicable joints too. Made sure that grease was tightly packed.

Blazer is riding a lot smoother now. Just as smooth as it was pre 100k miles.

So I've concluded anything that is serviable with grease, should be serviced and made sure there is enough.
If grease isn't tightly packed, I'm guessing that allows for enough play to cause things to shake.

Someone mentioned to me that ball joints should be serviced almost every oil change.
When I checked them, they were basically bone dry. And I just rebuilt the whole front-end last summer where I greased everything.
I didn't realize how often that needs to be serviced and what it can cause if not.