Knocking noise when I use 4x4 on 1981 G174

[keltonkrew]

I have a 1981 G174 by Bolens (Iseki). When I engage the 4wheel drive, I hear a clunking noise from the center of the gearcase. I speeds up with revolutions and keeps pace with the speed of the wheels. When I take it out of 4wheel drive, no noise.

I've been leaving it in 2 wheel drive mode. I've had to use the 4x4 mode some, but I keep it slow so it doesn't make that noise.

any ideas where to look?

Thanks

 

[lens12]

I'd recommend tearing it apart before more damage is done. You may have stripped the teeth on the ring & pinion gears. I can supply you with parts.