I just got a 98Scab 4.6.I checked it out and everything was fine.I drove it for about 500 miles and had the oil changed. I told the guy to check everything and made a point to tell him to check the rear end because I have to drive 54 miles one way to a job site.He tells me everythings fine. So afther about 2 weeks I start hearing this noise from the rear end,I go to a shop I know and we put it on the lift. The rear end is almost a pint low. So we get the right fluid (Mobil 1 75/140?)and fill it the noise is still there and seems to be getting louder!The guy a the shop thonks its the pinion bearing but is not sure. Should i have this replaced and what should it cost? I am really pissed off because I trusted this guy at the oil change place,I have been going there for years. They changed the oil in my old truck (91 scab 4.9) and my car .I know the owner but he was not working there that day.I am going to talk to him tonight after my 54 mile ride home.Should I have a Ford dealer look at this?I read a lot of posts on this in the search.and it seems like a crap shoot. I apprecate any advise Thanks Bob

 

You can find a qualified mechanic at Ford or elsewhere. It's best to get a recommendation and go to a place that commonly does rear end work. You're not going to get an accurate price until the problem is properly diagnosed. Here is a website that helps with noise diagnosis: www.ring-pinion.com/tech/techind.html Scroll down to "General Information".

 

How loud is it and when does it make the noise. My 2000 9.75" rear has recently started making a little noise at low speeds when I get the throttle position just right. The 8.8 and 9.75 both hold 2.6 qts. so a pint low probably would not hurt it. If I remembe correctly, the manual says fill it to within 1/4" of the fill hole which may be about a pint lower than the fill line. They probably did just fine at the lube joint. When I did my brake job at 80k, I noticed the right axle seal was leaking and replaced it. I may have a pinion bearing going bad, but it isn't getting any louder, so I don't think so.

 

I just got my truck back. the carrier bearings in the rear end where shot. I cost me $520 and I had 1 ball joint and plugs and wires installed (Motorcraft). I had it done at an independent shop. I went to school with the owner , but we are not real tight or anything. Thanks for repleys.