99 ranger4X4 XLT 4.0L auto 4dr.

[jbfnew@msn.com]

Ideas needed- Grinding from left front (rotor and pads are good), ABS light is on. Thump on accelaration like a u-joint but it's not. Heard this can come from old grease under dust slinger boot on drive shaft?

 

[Jspafford]

The thump is probably the dried out grease on the driveshaft splines.

Grinding could be any number of things. CV joint, Bearings, Etc. The CV joints usually pop when they get worn, and the bearings are a sealed unit design meaning they are not serviceable and must be replaced as a whole, per side.

 

[woodyedmiston]

The ABS light being on is the tell-tale thing for me. The level of your brake fluid has dropped because the pads have worn enough to displace the fluid. Telling me that possibly the pads on your brakes have worn to the point that there is a slight edge rubbing against the side of a slight ridge at the outer edge of your rotor and/or the edge of the rotor is beginning to contact something about the caliper/piston/pad - you can slap on a quick fix by applying pressure to the pads after you have removed the calipers from around the rotor and then opening the bleed valve and pushing the pistons back - don't loose pressure with your screwdriver or whatever or you will pull air. Stick in a set of pads and put the rotors on - you should top off the master cyl. and it should take no time to bleed the brakes. - Do not let this go on too long w/o cutting the rotors. You will buy time by adding the pads - but the noise won't go away. Although you say your pad is "good" it seems that Ranger rotors are pretty soft - my current ranger is my 5th since 91. The noise is pretty common in my experience. It's caused by the rotor wearing under the pad but not at the outer edge - sort of like a piston ring ridge on a high mileage motor.

Those of you who read this and want to say "you must" always cut the rotor don't get your udies in a wad - you don't think pro racecar teams resurface rotors every time the change pads do you?

 

[jbfnew@msn.com]

Thanks to all, I cleaned the slip joint on the driveshaft and put on a new dust boot ($20), that took care of the thump- I bought new drilled rotors with ceramic pads and for two days i have not had the grinding.