I have an 07 660 Grizzly, that after my son pulled a buddy out of the creek, makes a clicking noise in the front differential as you drive forward and will not engage the front wheels. He was using the wench, but decided that was not fast enough and started to backup when it broke, bad idea.

Before I start taking things apart, any ideas what this might be? Or any tips for the disassembly?

Thank you in advance!

 

They are pretty straight forward. Put the switches in 2wd before you pull the servo motor off.
There will be a paint spot on it the servo gear #18 and and the rack gear #20. Often the fork the rack #21 moves that engages the the slider #30 to engage 3 or 4 wheel drive, gets bent and needs straightened or replaced. From there it depends on how the slider looks. If the rider is on the throttle before the slider engages the teeth on it will be worn or stripped.
It is important to wait until the 3wd or 4wd lock indicators are on before mashing the throttle.

Pulling on the winch in reverse should not have hurt the diff if it was fully engage.
It is also possible it stripped the splines on the front drive shaft at the front of the tranny.
It is common for the drive shaft to wear out the splines and strip.
Here is a picture.
2007 GRIZZLY 660 - YFM66FGW Yamaha ATV FRONT DIFFERENTIAL Diagram and Parts
I have a manual to
Free Cloud Storage - MediaFire

 

Thank you for the reply and the diagram. This gives us a great starting point and I hope to be getting to this soon. I had purchased a manual when I bought the griz, but your explanation helps make sense of the "exploded view".

Funny they never never look like that when you have all the parts laying on the bench.