i just noticed a grinding sound today on my 185s every time i im getting ready to shift in 4th im hearing this grinding nosie?

is my axle bent?
is there some thing wrong with my gearbox?
or is it just wear and tear?
dose something need to be oiled ?

 

Mine did the same thing
How long has it been since you checked the drive chain adjustment
It is probably gringing on cover when in 4th gear and slacking back and forth causing noise
Ray