My 2004, F-150, Heritage, with 3.31 rear and 110,000 miles has been making a wherrring noise from the rear end at about 50mph, for about 5K miles. It sounds like I am running big mud tires. I don't haul or tow any weight. I see there is a TSB -4-25-08 with a kit that may fix the noise issue. However, it doesn't say whether this is a fix for a "low milage" noise or a 100K+ fix. I got a quote from the dealer of about $1,500 to install the kit. Does anyone have experiance with this type of noise and their thoughts on the fix kit vrs a full rear end replacement? Also is this a must fix soon, or a wait awhile fix?

 

My guess is pinion bearings....not sure on the differences in '04 vs my 2K but mine did the exact same thing and that was the problem. Ultimately, fix it now, it will only get worse and then $$$$$$$$

 

Many thanks. Any other ideas?