96 F-150: pulsating rear brakes after new Eaton

Ok, now I'm concerned.... Reference my previous posts, got a new Eaton posi unit put in my 96 F-150 auto short box, and now the rear brakes pulsate A Local 4x4 shop did the work, and put in new axle shafts, bearings, and the Eaton unit. I just put brand new brake drums on tonight thinking that they were out of round, but it's still doing it: Rolling down the road, and apply light emergency brakes (to completely eliminate the front rotors etc), and the back starts to pulsate. Apply a light pressure to the main brakes (while there is a tad of emergency brakes) and it *really* pulsates. The only thing that I can think of is that the new axle shafts are not straight. (is that possible?) Wheel bearing pressed on wrong, or canted on the shaft? Or, is it possible that there is some normal interaction with the posi unit itself? Maybe the clutch's inside are "hunting" or something when the rear wheels brake? Advice needed. Thanks!

Reply to
Mr Wizzard
Loading thread data ...

Check the torque on the lugnuts. Your new drums might already be warped.

Reply to
Junior

I'm thinking your rear abs has the sensor (tone) ring inside the rear diffy, and the abs sensor itself mounted on the outside of the diffy up near the top. I think the tone ring may have not been reinstalled properly. So your abs is activating when you stop.

Won't be axles or wheel bearings - they would vibrate all the time, not just when you applied brakes.

Since you got drums, apply the emergency brake manually to stop the truck (don't use the regular brakes). If there is no vibration, then the drums/shoes are fine. And that pretty much points you at the abs.

Reply to
late night via CarKB.com

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.