Roaring gringing noise in Auto4wd

[04tahoels]

hi i have a 2004 tahoe ls 5.3l Flexfuel with 157k miles on it when i select Auto4wd i hear grinning humming noise coming from front end of truck i changed both hubs and differential & transfer case fluid level all ok still can not find where the noise coming its mostly noticeable between 10mph up to 30mph and on slow left turns. if anyone has idea whats the noise is i appreciate it thanks for the helpful forum

 

[Donnie Yukonie]

I moved this to a more appropriate section ,

Im having trouble understanding what you replaced Both front hubs AND Differential? or did you just check the Diffs Fluid?

Also does this sound Replicate in all 4wd modes or just Auto?

 

[04tahoels]

hi, i just check fluid level in differential and transfer case and it was ok. its more like a rumble noise like mud tires noise

 

[Donnie Yukonie]

Ok , so this noise doenst occur in any of the other Modes I.E 4wd Hi, 4wd Lo?

How does the front Ujoints look? are there any play in them? and have you noticed any Ripped CV Joint boots?

 

[04tahoels]

it accours in all 4wd modes in 2wd no noise att all i havent check the CV or The u joint i will check them when i have time and let you know

---------- Post added at 10:31 AM ---------- Previous post was at 10:30 AM ----------

When I driving in 2Hi everything sounds fine. If I put the truck in Auto4WD or 4Hi I get a rumble noise that sounds like a truck with mud tires. Not quite as loud, but it changes tone with speed

 

[afpj]

In addition to what donnieyukonie suggested, consider just changing the front diff fluid since its easy to access. Transfer case a little harder IMO & gotta be careful due to soft case material (strip threads on tcase). Look at what's in fluid when it comes out. Also, if you're trying the to locate sound yourself can be quite tricky. Had a 'wowowow low rumble sound on slow right turns & couldn't tell where it was coming from until I had a friend listen...turned out to be rear differential. Check (better yet change) rear diff fluid too. Please let us know what you find. What hubs did you replace with? Cheap hubs fail quickly...

 

[04tahoels]

hi i replaced both wheels hubs with timken whats fluid do you recommend to replace it with 80w or 75w synethtic or regular . thanks

 

[Donnie Yukonie]

The Transfer case fluid is not hard to change at all , there are two plugs a Fill port located more to the top and a drain plug at the bottom , In order to get to the Bottom plug you would have to remove the skid plate if equipped .from what your telling me Its sounds more like a Transfer case issue but lets not jump to conclusions just yet , again Id check the Diff fluid as well Might not hurt to change it with the Auto Trak II fluid (ill check if this is the right fluid Pretty sure it didnt change with the two body styles )

---------- Post added at 01:46 PM ---------- Previous post was at 01:45 PM ----------

Found this helpful link and to confirm you do have to get Auto Trak II if your due for the change
http://www.gm-trucks.com/resources/how-to/2009/01/28/changing-your-transfer-case-fluid/

 

[04tahoels]

Thanks a lot for your Info Ronnie but manual says autotrak ll only in Transfer case and 75w90 in differential the autotrak is blue fluid for transfercase only according to manual

 

[alacran]

I have a problem similar to this but on (some not all) slow turns. it hops like a stop n go affect. Mostly with 4auto on. I wonder if it's the same thing going on with your truck