[Matty04dually]

Hey guys. I just got my trans rebuilt and went full billet, gettin ready to throw some fuel and air at this truck and hopefully make a 700hp daily driver. It’s an 04.5 dually, I’m not sure what gears these came with or if it’s an open or limited slip?? Only spins passenger side when I power brake, and when I went to the snow yesterday it seemed to do a little of both, one side spins or both sides at times. Not looking to do a gear change yet, but I would like a solid setup for a daily driver. Obviously not going lockers, but what options are out there? What are you guys who are making some power and use your truck for daily and occasional track time using? Definitely going to the track next year.

 

[Baja]

What rpm are you @70 mph? With a 3.73 you should be around 2000. There may be a tag on the diff cover that will give you the ratio information. If all else fails, get your vin#, call the dealer and get the build sheet. That will have everything you need to know printed on it. This will include if you have a LSD or open diff.
Bad news is that there is very little aftermarket differentials for the AAM 11.5. They have only been making it for about 15+ years, yet there is not much out there. Why Eaton has not made a E-Locker for it is beyond me, makes zero sense. I know I would buy one tomorrow if they came out with one. You guys listening??????
No need to worry if the diff can take your power, it will, no issues.
There are several tests you can physically perform to see if you have a open or LSD. Put one wheel in dry dirt, other on pavement. Hit it and see what happens. The pavement should lock up. If you use snow or ice for the wheel, sometimes it is a bit harder to get the pavement to lock up. You will have to hit the brakes lightly to "fool" it and get it to work. A hassle. Personally I think the stock LSD is junk, although others seem to like it a lot. Jack both rear wheels in the air and spin them by hand. If both wheels spin in the same direction, LSD, if they go opposite, open. Good luck.

 

[trevdogg67]

I had a tru Trac rear diff installed and I love it.