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Discussion Starter · #1 ·
Hello everyone. I have this 2006 Trablazer LT that was running real nice. One day big pop noise on the highway, no more torque. Turns out rear differential and gearbox were dead.

I found a decent garage that switched rear and front differentials and gearbox with functional used parts. Now it runs very smoothly, BUT the car sounds like it's constantly in reverse. Not sure how to explain that better, it really has this typical rc car type of whine to it, that directly reacts to the acceleration pedal. It's not as predominant as actually being in reverse but it's really there.

Mechanics says he can't hear it that much / it's nothing / it's gonna go away .. So basically I guess he has no idea what it could be.

Any leads ? I believe if I get this guy in the right direction he might be able to fix it.
I live in Greece by the way so these cars are pretty uncommon around here.

Thanks in advance !
 

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'05 Chevy TB EXT
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Seems to me there's too much ouzo involved ....

Differential gear noise never goes away ... it gets worse and worse until it destroys itself.

They put in a really bad rear differential and they don't want to guarantee their work or the used parts.

"FIX IT?" ...... no .. REPLACE OR REBUILD IT CORRECTLY.

This is prime reason why I NEVER advocate for used parts.

But why did they change 1) the front differential, 2) the transmission AND 3) the rear differential? Can't they diagnose bad parts in Greece?

Sorry for the now corrected typos --- I was on a cellphone and the keys are so tiny!

Now I'm on my laptop and it has a somewhat real" keyboard --- but I'm still not happy with these keys that are too TOO easy to accidentally hit.
 

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Discussion Starter · #3 ·
Seems to me there's too much ouzo involved ....

Differential gear noise never goes away ... it gets worse and worse until it destroys itself.

They put in a really bad rear differential and they don't want to guarantee their work or the used parts.

"FIT IT?" ...... no .. REPLACE OR REBUILD IT CORRECTLY.

This is prime reason why I NEVER advocate for used parts.

But why did they change 1) the front differential, 2l the transmission AND 3) the rear differential? Can't they diagnose bad parts in Greece?
Basically there was one differential dead, and the gearbox, so he had to change both. But then to get the proper ratio between front and right he also changed the front one.
I think he diagnosed as much as he could but yeah, definitely winging it over there, no deep knowledge of those cars I'm affraid.
 

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Basically there was one differential dead, and the gearbox, so he had to change both. But then to get the proper ratio between front and right he also changed the front one.
I think he diagnosed as much as he could but yeah, definitely winging it over there, no deep knowledge of those cars I'm affraid.
It's not a "those cars" scenario ..... a differential that's screaming telling you something's wrong with the gear tooth pattern is gonna be the same no matter if it's an 18-wheeler or a kiddie car.

Maybe you went to Sears or WalMart Auto Service where the "mechanic" was used to asking if you wanted to Super Size your order ... yesterday.

Whomever he/she/they/them or goat ... whatever they identify as ..... is not a mechanic ..... nor a very good goat herder either.
 

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What "gearbox" are we talking about? Transfer case?

I'm VERY suspicious about the rear differential AND the transfer case making a single "pop" and then both fail. One or the other, I'd understand. Both seems...unlikely.

The replacement rear axle was of a different gear ratio than the original? So the front differential had to be changed to match ratios?

I would want to do whatever diagnosis it took to find out if the noise is coming from the front differential, rear differential, transfer case, or "somewhere else".

Are the correct fluids available in Greece for refill of these components? The transfer case in particular needs "special" GM Autotrak II fluid (which is probably Dexron III with blue dye instead of red, and three times the price. But I don't know that for sure.)
 

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@Shurkey --- you're forgetting that this poor poster got shotgunned by an incompetent "repair shop" and they don't know what went wrong so they just changed everything they were comfortable with .... or was available in a junkyard ... or not!

They cannot communicate with the owner as to what a "gearbox" is ..... nor did they care, it seems. The customer is in the dark and he isn't gonna be much help in decoding their gibberish --- so ... well, you see what I mean .... right?

I've got dollars-to-donuts that the reverse-gear sound is exactly what I said it is --- a bad rear differential.

The "popping noise"? Who really cares --- this post is not the fault of the OP --- and he can't really tell .... just the sound as it relates to his life experiences.

If I was a betting guy --- I'd think a popping noise could be everything from a blown u-joint to a snapped pinion or a busted Hy-Vo chain or a pedestrian with a hipflask.

I feel sorry for him, getting snookered like this --- but .... hell ... he's in another country and I can't physically see, hear, diagnose or shoot the bad guys for him --- even if I wanted to ... and I WANT TO do almost all of those things for him .... well ... mostly, anyway.
 

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Discussion Starter · #7 ·
@Shurkey --- you're forgetting that this poor poster got shotgunned by an incompetent "repair shop" and they don't know what went wrong so they just changed everything they were comfortable with .... or was available in a junkyard ... or not!

They cannot communicate with the owner as to what a "gearbox" is ..... nor did they care, it seems. The customer is in the dark and he isn't gonna be much help in decoding their gibberish --- so ... well, you see what I mean .... right?

I've got dollars-to-donuts that the reverse-gear sound is exactly what I said it is --- a bad rear differential.

The "popping noise"? Who really cares --- this post is not the fault of the OP --- and he can't really tell .... just the sound as it relates to his life experiences.

If I was a betting guy --- I'd think a popping noise could be everything from a blown u-joint to a snapped pinion or a busted Hy-Vo chain or a pedestrian with a hipflask.

I feel sorry for him, getting snookered like this --- but .... hell ... he's in another country and I can't physically see, hear, diagnose or shoot the bad guys for him --- even if I wanted to ... and I WANT TO do almost all of those things for him .... well ... mostly, anyway.

Hey so you make a lot of pretty rude assumptions here and in your other answers, but hey if that makes you feel good behind your keyboard you do you. Thanks for the few actual suggestions that slipped in.

@Shurkey Yeah it was a ratio issue, basically they had to match the front and the rear. And yeah I don't really know about the fluids etc, but it's a garage specialized in 4x4 and the only one around Athens that accepted to do some work on my car so I think they know what they're doing to some extent !

The new here is that they managed to fix the whining noise and it's now all running very smooth. Gearbox and everything was actually fixed properly, the noise was coming from the catalytic converter. Case closed, nice day to y'all ++
 

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Hey so you make a lot of pretty rude assumptions here and in your other answers, but hey if that makes you feel good behind your keyboard you do you. Thanks for the few actual suggestions that slipped in.

@Shurkey Yeah it was a ratio issue, basically they had to match the front and the rear. And yeah I don't really know about the fluids etc, but it's a garage specialized in 4x4 and the only one around Athens that accepted to do some work on my car so I think they know what they're doing to some extent !

The new here is that they managed to fix the whining noise and it's now all running very smooth. Gearbox and everything was actually fixed properly, the noise was coming from the catalytic converter. Case closed, nice day to y'all ++
Let me get this straight .... you actually disagree with me?

Dayum!
 
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