Steering wheel pulses from left to right while driving

[Dabake]

New Member here. I have a 2008 Dodge Ram 1500 4x4 Crew Cab - I changed the rear differential gear oil with Valvoline 75W-140 with anti-slip additive included. Now when I drive the truck the steering wheel "slowly pulses 4 to 5 inches" from left to right and with hands off the steering wheel it pulls to the right. I checked the steering box and wheels for loose or worn issues and found none. Is it possible the anti slip additive which was included in the gear oil not compatible with the Dodge posi-trak which might be causing my problem? Any ideas would be appreciated. Thanks

 

[Recoil]

Anti-slip doesn't work that way. It will not feed power to one side or the other while driving in a straight line unless you are smashing the gas pedal. I personally don't use it because limited slip differentials do not need more "slip" added to them.

If in doubt, drain it and put in fresh gear lube.