Click noise when shifting to Reverse

[1997F350bully]

Hey guys,
The past couple of days, when I pull up to my house in drive, I then proceed to put it in reverse, it makes a wierd click noise, once the reverse gear engages. It makes the noise when it initially shifts into reverse, but no noise after that, it doesnt make the noise going into Drive. Its on a 2006 F-250 5R100 torqshift tranny, 4x4. HELP Could it be the reverse snap ring, wasnt there a recall on them.
:HELP: :HELP: :HELP:

[LilGuy21585]

Hey had same prob... turned out to be u joints on drive shaft took driveshaft down to local fleet shop and had them install u joints and ballance driveshaft... not to mention i just had it snowplowing