Ok I'll try that too... It came out of nowhere, and only does it once in a while. Would you guys recommend adding more additive or draining it all and using synthetic?
My 95 3500 Cummins 4x4 would do this from time to time. It had a clutch type Dana 80, I would add a bottle of additive to it and it would be fine. They tend to grab or chatter more when under load and turning.
