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2002 chevy
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83 Posts
Discussion Starter · #1 ·
Hi
May wrong fluid in TC be the cause of whining sound??.

I have not been able to check the fluid since i bought my TB because of the cold weather and not having access to a garage. The TC is supposed to be changed about 12,000km before i got it and im not sure if the right fluid is in there.

The thing is when i put the TC in A4WD it makes a brief whining sound just for a second and then goes away just to come back as soon it needs to engage and then fades away.

In 4WDHi it makes the sound all the time, it sounds like a tyre is rubbing against a loose inner fender or something similar. The sound comes from passenger side floor area.

Everything works as it should, no blinking lights or anything. Both front wheels is pulling just fine, just this annoying sound.

To be honest i thought this sound was normal(4WD noob) when i first tried the TB before i bought it.:duh:
Now i know it isn't. The sound have not gotten any worse over the time ive been using it(5000km), lately almost every day because of the 20" of snow here.
 

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2005 chevy trailblazer_lt_ext
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26 Posts
It is possible it could have the wrong fluid in it and that is causing your problem, but it is more likely that you have an internal problem with your transfer case. One way to find out is to crack open the drain plug on the bottom of your transfer case and check the color. If it is the correct fluid it will be blue, or in your case very dark blue if it has never been changed
 

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2002 chevy
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83 Posts
Discussion Starter · #3 ·
I quite sure that the fluid has been changed when they switched the TC 8000 miles ago, but im not sure WICH fluid that has been used and i cant check it right now either due to the weather.

My plan is to check and replace the fluid as soon as i can, i started two weeks ago but i only managed to do the front diff then i had to give up because it was freeeezing cold -16c.
 

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Banned
2003 gmc envoy_slt
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7,190 Posts
It is possible it could have the wrong fluid in it and that is causing your problem, but it is more likely that you have an internal problem with your transfer case. One way to find out is to crack open the drain plug on the bottom of your transfer case and check the color. If it is the correct fluid it will be blue, or in your case very dark blue if it has never been changed
I would advise against this just for checking color. The fluid really gushes out if you go to far. Also, you should make certain the fill plug can be removed before removing the drain plug.

Remove the fill plug and insert a screwdriver.
 

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2002 chevy
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83 Posts
Discussion Starter · #5 · (Edited)
OK
Today i managed to do some work on my TB.
I checked and changed the TC fluid, wich was blue and reasently changed
by the look of it. No metallic fluid or shavings either.
I also did the rear diff. The fluid was brown and the smell was worse than usual,but no flakes or shavings.

I was also checking the shafts, i found some movement in the front propellershaft at the TC end.
Is that normal or is this my problem?.
Remember i have this grinding,moaning sound when in 4wdhi and in A4wd when engaging and just a very faint sound in 2wdhi and only at speeds right before shifting from first to second gear.

I did my front diff earlier and there was no metallic or shavings there either, today i saw that i have a leaky oilseal at the propellershaft end, but thats a easy fix. Just have to keep an eye on fluid level there until i get it fixed.
 

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2004 buick rainier
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290 Posts
Bad front wheel bearings can make humming, groaning, and grinding noises depending on how bad they are. However, I've never heard of the sound changing based on 2WD/4WD, but I guess anything is possible.
 

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2003 gmc envoy_slt_xl
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24 Posts
does anyone have pictures on how to change the Diff and TC fluids? i like doing things myself because you don't get messed over that way. i do know that i have to get the TC fluid from the dealer. any how to picks or component diagrams would be appreciated:)

sorry i just found that thread
 

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Banned
2003 gmc envoy_slt
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7,190 Posts
You're lucky, the 2003 still has the drain plug in the rear diff, also the rear diff cover gasket is reusable.

Just make sure all three fill plugs are removable before removing drain plugs.
 
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