For off road purposes, what is the best option to replace an open diff in a mopar 9.25 rear end? The vehicle in question would be over all a close to stock, mild build. Top of my list would be a cable actuated locker, but it would seem one isn't available. I have found just about every other style.
I did the Powertrax unit in mine. Works well off road though it can be noisy. And sometimes the unloading "clunk " will scare you a bit if you are on really weird grippy but not grippy situations. For the price and ease of installation ID go this way again in a 9.25. Otherwise the only options I see for the 9.25 are $1100 and a full carrier replacement. That carrier replacement might also require new shafts if you are not currently a 33 spline. And for that kind of cash you may as well buy and modify a locked D60 from someone else's failed or wrecked project.
What are you putting it in?
This would be on a last gen Dak.
Mine is a first ten durango so it's likely pretty similar in terms of shafts and splines. I know Durangoso could be had with an LSD as a factory option. Have you considered boneyard sourcing one of them? It would probably be the cheapest upgrade. And to be honest is probably a better option than a full time locker unless you are using it just for the mud.
Maybe a mechanical limited slip? I just purchased Detroit Trutracs for the front and rear of my JK Wrangler after about a month of research. I don't plan on using my Jeep for rock crawling or KOH but for fire roads and rocky desert trails (mud too!), they should be perfect. I chose the Truetracs because they met all of my criteria:
Cost effective (sure ARB air lockers are awesome but $1200+ per axle is too rich for me)
Good winter traction (no goofy lockup shenanigans)
Longevity (I didn't want a clutch based system)
Usability (no wires to run or air lines/compressor install and they work with no intervention)
Drivability (no ratcheting like a lunch-box locker, no weird sounds or binding on pavement)
They won't be very effective if you plan on crawling (ie- lifting a tire) but for everything else, they should work pretty good.
I wanted to replace my open differentials since I am doing a gear install anyways. Same amount of labor
PS - the part number for your Dodge 9.25 is 913A368 for the Truetrac and 187C172A for the Detroit Locker
just weld the spiders if it is going to be an off road mostly vehicle.