I have a '96 Ram 2500 CTD 4x4 Auto and tow a 14000 lb horse trailer.
I'm in need of replacing the rear differential. When I turn corners, it feels like the rear wheel is locking up or slipping (like driving on pavement while in 4WD).Can anyone who has experienced a similar problem give advice on if a heavier differential is available that will carry the weight? I carry 6800 lbs on the rear axle when the trailer is loaded.

 

Well, that probably has a Dana 60 in the rear, which should be stout enough to handle that load. Probably just needs to be rebuild. Have you removed the cover to see what might be wrong inside?

Or, you could get an axle off a 3500, which came with Dana 70's and Dana 80's. Or you could look for a Rockwell.

 

I replaced the gear oil 3 weeks ago with Amsoil plus L/S additive. No metal shavings found. I have a Dana 70 limited slip (stock). Surge is more pronounced with heavy load.

 

Does this happen regardless of cornering speed and throttle application? Or only under sharp turns and heavy acceleration? Are the tires good?

 

No. It just happens at low speed turns (or that's where I notice it). It's more pronounced when I have my trailer hooked up and making sharp turns.