I am getting a low howling, or humming noise from something under the truck, I cannot quite place whether it is in the rear end or elsewhere just yet. Changes Diff Fluid twice since I owned the truck, front seal replaced once by ford due to minor leak. No problems since other than this. Diff case is full of fluid. Gears looked brand new and absolutely no metal or break in metal was in case during fluid change previously.

Thanks,

Dave

 

I just had the pinion bearing replaced in my 2000 F150. 68,000 miles. It was making a loud " whinning/whirring " type noise at speed that was a growling noise at 20 mph. Unfortunately I was 700 miles from home at the time, with another 2100 to go. I had this same problem with a 98 Explorer at about the same milage.

 

Thanks,

Could you hear it at low speeds as well?

How did you get this diagnosed?

Know a place that will diagnose this without ripping you off?

Thanks,

Dave

 

As it got louder at speed, it began to be a low pitched "rumble" at 20 mph. I pretty well diagnosed it myself, it was obvious that it was occuring at driveshaft speed, and from the rear. I stopped at a Ford dealership and they confirmed it. It was a $1016.00 charge at the dealership. I am sure if it had happened here at home and I was not forced to use a dealership, it probably would have been half that.