Originally Posted by campism
This is good information for a diff noob. I'm presently awaiting a replacement from a local junkyard for my van's Dana 60 with 4.09, the result of a decision I had to make when learning that the howl from my van's rear end meant rebuild or replacement. Even with mechanical skills and motivation, the lack of specialized tools and knowledge (plus cost of rebuild kits and gear sets) made betting on a junkyard unit worthwhile. I would not have been changing ratios but the amount of work would have been the same.
I'm pretty sure your 4.09 ratio is 4.10.....41 tooth ring and 10 tooth pinion.
There are special tools needed, the way I looked at it is that for less than the cost of labor I can buy the tools, use them, them sell them for 60-70% of what I paid for them.......and get two big advantages.....
...which reminds me...I need to list the bearing puller and setup bearings for sale....
I learned how to properly install a R&P (loads of info online/youTube) and I know it's done properly. If it fails I know the idiot who installed it.
Although the job is repetitive/tedious, it's lots lighter than installing a new axle.....and I refreshed all the seals/bearings while in there.