Note: This review was written a number of years ago but may still be interesting to some.

Recently I was asked to evaluate the IRS pro diff. My first impression
was, WOW, what a finish! No wasted time to polish these babies. These parts have the best finish I've seen, for right out of the package factory aluminum. This diff is of excellent machine detail, making it a very functional piece. The pro diff is easy to assemble, the hubs line up perfectly with the wheels. Previous diffs I've owned, I've had to drill the holes for the pins, myself. Not the easiest job! The IRS pro diff has the holes drilled for you, cutting time and aggravation. The dual split hub attaches more securely then a single split. I checked local hobby shops to see if the hub size was consistent. Other hubs can vary greatly in size. This is not the case with IRS hubs, they are all the same size.

If you crash, and we all do, there are maintenance advantages to the IRS diff too. Glued diff rings can break loose after a crash. An IRS pinned diff cannot. The pro diff also eliminates the need for a left side spacer. (One less thing to roll around on the table.) As well as, the inconsistency of a thrust cone and bevel washer setup.

I find the IRS pro diff to be highly functional, convenient, worth the money and better looking then me.

Bret "THEJET" Lund