Yesterday I went wheelin and since the trail was only about 30 miles from my house I drove. I really don't drive it much on the street but I did. Anyways, while braking for a one lane bridge my rear axle start twisting. I could feel it in the pedal. It was like I was hitting the brakes really hard and letting off fast over and over. It was so hard it was wrapping my springs and making them slap together. It only did it that once til after we got done wheelin then it did it once more. It was almost like they (rear) brakes were getting way too much pressure then relaesing then pressure again. The rear axle is from a 95, the booster and brake lines are original 85 stuff, the M.C. is from a 94. I have removed the rear proportioning valve. Any idea before I start tearing into the rear brakes?