we have a 2000 3500 w dana 80 35 spline 4.10 gears need a spider gear set for the rear dont know if its a trac loc or posi loc ??have been surfin net 4 a few days and can find a kit #707358-1xseems to be the right kit but not sure and can only find it on a wholesale web page (have to buy 150 kits) anyway can anyone help us fix this old truck any and all help gladly accepted thanks bb

 

try pirate4x4.com. good luck

 

Call Randy's Ring & Pinion, or Reider Racing. Either should be able to help.
It is very likely that you have a limited-slip diff. I've not yet seen a D80 in one of these trucks that did not have it.

 

Jack both rear wheels off ground and spin wheel if other wheel turns opposite direction you have open case diff. If both wheels turn same direction you have posi type diff.

 

as near as i can tell all that was in the d80 in that year was the trac-loc

 

his question was not if he has an open type diff but which type, trac-loc or posi-loc