Rear diff rebuild

[Vimes]

This is for my wife's daily, a 2021 Durango R/T rear wheel drive. We had a mess of snow last week and even I could not get her Durango up our driveway. My POS beater truck, no problem. The Durango has an IRS rear with a 3.09 ratio, open diff. The only option from Dodge was an electric locker, and from what I've read either it comes with the electric locker or there's no way to add a locker. Sadly, RWD only Durangos are already rare as hen's teeth so we had to take what we could get.

Today I spoke with a local diff shop I've used from time to time. They checked and found that the unit is not rebuildable, it's replacement only. I can't accept that for a differential. Does anyone here know of a shop that rebuilds these things? Don't care where, I can pick up a replacement for a couple hundred bucks and have it shipped if there is a reliable shop that can do IRS diff rebuilds. I'd need someone who can think on their feet and make things work, not some by the book guy who can't think outside the box. Any assistance would be appreciated.

[Hotwire]

Your wording is off. You don't necessarily need a rebuild, you're just looking to replace the open diff with a posi. If you can't find a shop have you looked at Jasper or any of the other mass renewal companies?

First thing I would do is dig in to figure out what size ring gear it is and if the aftermarket supports it.

[Vimes]

Ehh, a rebuild shop is the most likely ones who would do such work. I've been checking around and so far, nothing. I just tried Jasper and while they can rebuild it, they can't give me what I want.

[Vimes]

Update, I checked with a local shop and they said no rebuilds, unit replacement only. But, never say die. I have found that the 2014+ Challenger had a non-electric limited slip with a 3.90 ratio, and also uses a 9.25 inch ring gear in their IRS. I may wind up having to buy one, and buy a Durango diff, then pull them apart and see what happens.