I have a 1999 f-150 4x4 off road with 177,000 miles. About 150 miles ago the rear end started howling upon acceleration only, it goes away when steady gas or deceleration. wassup?

 

I have the same problem. Check TSB 05-23-3

 

I bought my 97 F-150 4X4 used w/ 64,000miles on it and the rear end (3.55 LS) would make a howling sound when u accelerate and it would stop if u let off the gas,it did it the worst at 45mph.
I talk to the guy who owned it before me he said it always done it since it wuz new and had Ford replace the chunk when the truck was still under warranty but that still didn't fix the problem.
I drove until it had about 110,000miles on it and one night I wuz coming home from work it started howling like never before,well it locked up on me going down S.R.80.
Up until that point though it never changed tone or nothing to indicate it was about to give up just that one night bam.Turns out it was the carrier bearings,I replaced the whole rear axle and just swapped the brakes off the old one too it.

Dan

 

Carrier bearing going bad.

 

Carrier bearings and/or pinion bearings.

 

Just happened to me, get it looked at before it takes out the whole gear set, $2400.00

Colin

 

I just changed mine. I bought the bearing kit from Randy's Ring and pinion. $250 the outer axle bearings from NAPA. $100 It took about 6 hours. It was a PITA. It requires a few special tools such as dial indicator, dial calipers or micrometer, torque wrench, inch pound torque wrench. Cured the problem.

 

I always heard that was a job you didn't want to do alone for the first time.

Did you have someone helping ya, or great directions?

 

I read as much as I could on the internet about differentials in general. I have rebuilt John Deere front differentials before with mixed results. Just remember, you cannot take shortcuts on this job. The guys at Randy's answered a few questions also.

 

got a phone number for randys ring and pinion? turns out it was my carrier bearings and my carrier.

 

They can be found here:

Randy's Ring & Pinion