Power saw noise

tyler

Original poster
Member
Aug 25, 2017
58
Boston
Hello everyone,

I have a power saw noise coming from my trailblazer. It sounds like someone is power sawing wood. It gets loud sometimes its a quiet noise. Not sure if anyone experienced the same noise and knew what it was. When the noise is present, my trailblazer feels like something is hugging it kind of slowing it down. I just replaced all upper and lower ball joints and wheel bearings, I know this isn't the issue. Not sure if it's even suspension, or maybe transfer case or something related.

Any help or advice would be great, Thanks!
 

Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
Does it happen when parked idling? Or only when driving? If only in motion, can you jack up the front or rear ends, spin the wheels freely, and hear/feel anything?
 

tyler

Original poster
Member
Aug 25, 2017
58
Boston
No, only happens when in motion, at random times to, it can happen anytime in motion, no specific time. But not when idling. When i spin wheels freely I don't hear anything. I was up till 330 am yesterday. Did both upper and lower ball joints.

Really bizarre, I think maybe something in differential or transfer case. Hopefully not.
 

Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
Yeah I was starting to think maybe the transfer case or front diff too. When was the last time you changed the fluids in those?
 
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Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
Have any idea where the noise is coming from? Front? Middle? Back? Can you feel it in the steering? Your feet? Seat?

Did you check the front axles? See if they move around inside the diff or the disconnect. The disconnect often fails at the outer bearing. Check the fluids in the TC and diff. Check the rear U-joints.

If thinking the transfer case or front diff, have you tried it in 4hi?
 
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tyler

Original poster
Member
Aug 25, 2017
58
Boston
It started making the noise a week ago when I did my first driver side upper ball joint and also changed my front driver side tire. Two days ago I did the rest of my ball joints. I don't know why but I think it has something to do with the tire. The tire was balanced. Sounds like it's coming from both front ends of the truck. Mostly middle and driver side. It's really strange. Kind of feels like it's hugging my car and a little pull to left or right. Sounds like a power saw cutting a 2 x 4 piece of wood. And the noise can be quiet sound or a loud sound. Might try to bring it to a tire place? I don't know but I'm stumped for right now trying to figure it out.

And no didn't get an alignment done after ball joint but doesn't feel like I need one. Maybe I do need an alignment even though the wheels straight when driving?

I do feel like pulling in the steering wheel when it tries to pull. Can't really try 4hi I need new power steering lines. I cut the rust off some of the line and put a rubber line on it as a substitute for now lol.

I didn't know you could check axles that way, I'm going to try to look another day. I was planning on getting two new axles anyways seems like my whole suspension needs attention.

Fluids in TV and diff are also clean. I checked two days ago m also changed them out about six months ago.
 
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Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
Recheck your ball joint work. Maybe something loose and rubbing on the tire thread? The upper BJ is close to the tire.
 
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tyler

Original poster
Member
Aug 25, 2017
58
Boston
Recheck your ball joint work. Maybe something loose and rubbing on the tire thread? The upper BJ is close to the tire.

definitely going to do this. Don't understand how I changed the driver side upper ball and changed a tire and this noise is present now.

Thanks!
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
It's possible that the hole the BJ goes in has been enlarged and is loose in it, allowing it to move. Or you're using oversized tires?
 
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tyler

Original poster
Member
Aug 25, 2017
58
Boston
It's possible that the hole the BJ goes in has been enlarged and is loose in it, allowing it to move. Or you're using oversized tires?

I was able to tighten the bolt that goes through the ball joint with a wrench a little bit. I was just using the wrench to see if there was any play up and down and it was tightening the bolt. Also when I move the car side to side, I hear a cricket noise in the driver side wheel well side. When I went to the passenger side and rocked the car side to side I heard it again but coming from driver side.
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
Usually that indicates worn A-arm bushings.
 

gmcman

Member
Dec 12, 2011
4,656
Like @Mooseman mentioned...when the bearing in my splined 4WD disconnect went bad, it sounded like a bucket of rocks and grinding when I hit a bump. However you said it started after you worked on the drivers side.

The only thing else that comes to mind to make a circular saw sound, would be the backing plate against the rusty portion of the brake disc.

Maybe you bent the backing plate, or installed them incorrectly.....I would double check those.
 
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tyler

Original poster
Member
Aug 25, 2017
58
Boston
Well I'm using my buddies van because the noise was getting worse, and then I tried going to store and couldn't go pas twenty mph because there was a loud banging noise lol

come to find out my control arm either upper or lower (been working haven't had time to look I do tomorrow) is banging against my tire and rim....

So I think my bushings are bad in either upper or lower, but I want to change all four bushings, it's cheaper than getting the bracket at the store. Is there a way to take bushings out of upper and lower control arms?? Hopefully that's the problem. My trailblazer has 175k miles on it and like I said before my ex went up on a big curb and put a foot gash in my passenger side front tire about couple months ago, so my suspension was kind of shot.

I already did all four BJ's, now I think my bushings are bad. Any other suggestions why my control arm could be leaning towards my tire?

Thanks guys for all your input, you guys are the best!
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
We generally just replace the upper arms and either the lower brackets or the complete lower arms. That's because replacing just the bushings is a bitch. Been there, done that, never again. You usually have to torch out the rubber and then punch out the cans.
 

tyler

Original poster
Member
Aug 25, 2017
58
Boston
Damn ok, I'm going to have to do some investigating tommorow on my tb to see what has to be replaced then. Either the upper or lower or both... Or something completely different 🙄 Thanks! But I do think it's the bushings that failed so I'm going to have to replace the arms and bracket most likely.
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
You can replace the lower brackets only if your ball joints are new and keep the arms. It saves a bit.
 
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gmcman

Member
Dec 12, 2011
4,656
Grab a hold of the passenger side CV shaft entering the splined disconnect and see if it wobbles around.
 
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tyler

Original poster
Member
Aug 25, 2017
58
Boston
So my front differential is shot. I'm going to junkyard tomorrow to get one specifically for my 06 trailblazer GU6 any good video tutorials on how to do this big job?
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
 
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mrrsm

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tyler

Original poster
Member
Aug 25, 2017
58
Boston
What's the gear oil capacity for the front differential case, so I know how much to get? I don't want to buy to much if I don't have to.
Thanks!
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
A quart will do it
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
You mean the intermediate shaft that goes through the oil pan? Put a bolt of the appropriate size in the hole on the end. I've used a slide hammer on the bolt. Some have been able to pry on it.
 
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tyler

Original poster
Member
Aug 25, 2017
58
Boston
Can you pull it from the passenger side before the differential comes off while still in vehicle?
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
yes
 
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Mooseman

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Dec 4, 2011
25,257
Ottawa, ON

TollKeeper

Supporting Donor
Member
Dec 3, 2011
8,047
Brighton, CO
Once the half shaft, and maybe the disconnect (cant remember), is out of the way, you put a bolt in the end of the shaft, and pull out. Most of the time, you can just thread the bolt, and pull. Rarely you need a puller tool to get it out.
 

tyler

Original poster
Member
Aug 25, 2017
58
Boston
So it was the differential, the housing on the side of the oil pan was hard to get out because the housing was jammed in from the impact months ago. So changed both components. Ended up getting a little hair line crack in oil pan barely anything. Ended up just jb welding it and letting it sit for 24 hours. Did a couple of applications so far so good. I also put synthetic gear oil in the new well junkyard used diff. I heard your suppose to use synthetic for front diff, and non synthetic gear oil in back but there's also a solvent you should put in the gear oil in back? Any idea what it's called? And thanks everyone for your help! BTW also did exhuast leaks luckily only both gaskets where worn out. No leak in piping. Now the TB is quiet as a mouae!
 
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mrrsm

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Sparky

Member
Dec 4, 2011
12,927
There is no limited slip unit in the rear diff (unless you have an SS) so unnecessary. But heck, half the gear oils have limited slip friction modifier in it already anyway.

I use the same oil front and rear diffs. There is nothing special about either that would require synth in one and non synth in the other. I used synth in both because that's just what I bought on sale.
 
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Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
Iirc, specs say to use synth 75w90 front and back. Only if you have a limited slip g86 diff you need the additive. SS, 9-7x, Rainier and Bravada with AWD transfer case have the g86.
 
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tyler

Original poster
Member
Aug 25, 2017
58
Boston
Hey guys, so it's been 1,600 miles since no problems with new differential and the axle disconnect housing or whatever it's called on the passenger side oil pan.

Now I'm starting to hear the same power saw noise again. I checked differential fluid and it's a cloudy milky color. Going to change fluid today, because another 1000 miles and the gears are going to break again. I know what comes after that power saw noise lol.

What do you guys think is going on with my TB? is there a special gear oil I should use since it's giving me trouble again?
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
That would be water. Check the vent tube to be sure it's not leaking and allowing water in. I'd change the fluid, run it a bit and change it again to flush out as much water as possible. Maybe a third time if it's still cloudy.
 

gmcman

Member
Dec 12, 2011
4,656
Just wanted to ask again since I didn't see a reply to my earlier question. If you replaced the front disconnect then no worries, but if not, what happens when you grab the passenger side CV axle and try to move it around at the disconnect? Is the axle solid or does it move around.

The vent tube is a more viable culprit but I'm curious to the fact that the splined disconnect has a good bearing and seal. Also could the splined disconnect allow water to flow through of the seal was bad?
 

Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
Water would have to go through two seals in the disconnect and one at the diff where the intermediate shaft enters. Driver side axle seal is also a possibility but you'd also have an oil leak. Pinion seal too.
 

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