Help diagnosing front end noise need professional help!

[johnnyt5646]

Well I need help, and what a better place to come to first. I'm sure we can figure the problem out.

I have a 2004 tahoe ls 4wd with 80k. bought it a month ago.

I have a intermittent noise. Sounds like a machine gun being shot on burst in no particular rhythm or length. I cannot create the noise by doing anything specificlly. It sounds like the front end drivers side but could be coming from anywhere. (I had a 2003 silverado that had a loose rear wheel that sounded like it was coming from the front. I ended up solving that issue by the wheel falling off). The noise happens more offten at higher speeds 60mph, but does happen at slower speeds but not as often. Happens and acts the same wheather in 2wd, 4wd or auto. What I do know is the front diff seal was replaced by the dealer. What is weird to me is the area where the seal is it looks like red grease. Like they used red grease as you would rtv. I will get a pic ASAP. In the area of the front diff it is wet. I assume the mechanic was lazy and sloppy got fluid on crossmember and didnt clean up with brake cleaner.

Tomorrow I am going to check fluid level. If the front diff does not have fluid would it hum or make a noise as described.

What else could it be. Open to troubleshooting suggestions.

I know it's not a wheel bearing.

I hope I gave enough info. Let me know if anyone needs more info. I am low on money so I need to figure it out with taking it somewhere.

Thanks in advance
John

 

[afpj]

Video or sound clip might help...
Do you have an assistant that can rev the engine while you listen in the engine bay? Does it only happen when moving? If the latter is true, then drivetrain is more suspect as you were alluding to.

Did you find what the fluid level was?

 

[johnnyt5646]

thanks for the reply

its not the engine. it has something to do with the drivetrain.

noise happens more when at higher speed. i have changed the gear oil n the front diff. looked new. it did not seem low. im thinking a bearing in the diff.

 

[johnnyt5646]

here are two pics with the red grease. its weird because it looks like trans fluid is coming from here. what kind of seal should be here.

 

[johnnyt5646]

here is another pic to help locate where im talking about

 

[tsb09000]

Just a guess but it might be your intermediate steering shaft (iss). I believe that is what is making a similar sound on mine from time to time but I haven't confirmed this yet. There are quite a few threads on here that speak of it though.

 

[johnnyt5646]

i will look into the iss issue. the last two nights driving to and from work i did not hear the noise.

 

[afpj]

that red stuff looks more like sealant than fluid?

 

[johnnyt5646]

the read stuff feels like grease. idk. i going to try the steering shaft first and go from there.