Engine/Transmission (1998.5 - 2002) strange downshift noise, whats your opinion on this?

[BLively]

i've got a question on a strange noise i get when i downshift. i have a 4500, i pulled about 24000 lbs the other day with the truck and thats when it started doing this. whenever i would downshift, it makes kindof a growling noise. it doesnt make the noise when upshifting or when its in neutral. any ideas??

 

[BLively]

does anybody have any ideas????

 

[TXDSLSHOP]

Where is FBG? Kind of hard to tell without hearing it. How many miles? Syncro maybe? Does it ever grind on upshift? Jeremy.

 

[BLively]

im from Fredericksburg. ya it only does it on the downshift side, through all gears, no noise upshifting or in neutral. i pulled another load yesterday, and it still did it, but seemed to kinda get quieter . it has 147,000 miles on it so far.