I recently purchased a '96 foreman 400 for 1200 in good condition with all new bearings, oversized piston, and all those other goodies.

Within two days of my purchase, I was riding in a field and noticed the front axle clicking like crazy, it stopped within a second and i thought it was a piece of mud caught on the tire or something, until it happened the next day, then I checked the axle.

There was a hole about 2 sq. in. in the front differential O_o
Im guessing something came loose? I really dont know, it wasnt there when I bought it.

My question is, what is the cheapest method to fix this.
What other models and years will fit?
This?
Honda Foreman 500 TRX500 FRONT FINAL DRIVE DIFFERENTIAL: eBay Motors (item 130405846798 end time Jul-31-10 06:17:40 PDT)

Im guessing they fixed this in 97 because of this:
HONDA FOREMAN 400 TRX400 FRONT FINAL DRIVE 97-01 G: eBay Motors (item 370405848275 end time Jul-09-10 17:01:35 PDT)
The years on it are 97-01
Please help ASAP