My Blazer hums when in 2hi, changing pitch based on speed. It stops in 4hi, so I think its probably the release valve. Anyway I work long hours and have an out of towntrip ccoming up soon, so I have no time to take it in. Is there any simple way of stopping the humming once (I won't need 4hi anytime soon)? If not, will the humming damage anything over approximately 1000 kms?

 

I am not trying to be rude here, but you have 97 posts, you should know the way around the forum by now, You should have posted this in the correct section, and not general talk.

 

Is there a way to move it?

 

A mod will have to move it. But that being said. hopefully someone will still come in here and help, I am sure someone will.
Are you 100% sure its the TC that is making the humming?

 

I looked at:

https://blazerforum.com/forum/tech-articles-diy-29/4wd-front-axle-clicking-when-2hi-goes-away-when-4hi-4lo-41226/

And it seemed to fit the description. The sound comes from the front and only happens in 2hi. Also I have the 3 button system.