The rear axle bearings are behind the axle seals. On intereral type diff's (like 8.8" & 9.75" in F150's), the axle brg's. can only be axcessed by removing rear diff. cover. Remove diff. cover (after elevating vehicle), use 5/16" wrench & remove spider lock pin & slide spider pin out. Then go to each out-board wheel & push axle in. Next, go to inside of differential & remove each "c" clip. Axle shaft will then be ready to pull out (from wheel end).
In most cases, I use the axle shaft end to pry out the old wheel seal. Next, use a (2) or (3) jaw slidehammer puller to remove the old axle brg. Very important! Refill diff after installing new wheel brg's. & seals & be sure not to overtighten the spider, lock-pin.

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1999 Teal Blue F-150 S/C
4.6L, XLT, 3.55 L/S
Tow pkg., Rhino liner, Engine block heater & hard toneau cover. Premium sound
255/75 r16 Generals-owl
"This is Mama's pride"

 

Is the rear axle bearings on the outer side inserted into axle housing behind the seal @ the back of the drum brakes housing? I am having some noise, my differential has been checked and said to be ok. Are these bearings the most likely the cause of my "whinning" noise? Thanks

 

gearmanx17, thanks for that description of how to replace rear axle bearings and seals.

 

Captain, do you know how they determined that the differenial gear assembly was ok? My 01 SC 5.4 L has a slight but annoying whine which sounds loudest around 45 mph coasting or very slight gas pedal on levelish roads. I went for road test with the service manager where I bought the truck and he thought it was the ring and pinion gears not mating properly. He wanted to have a mechanic check it out to be "sure" but I postponed that option. I will take it to another dealer soon to get another opinion.

 

My truck has been doing the same thing since brand new. I took it to the dealer and they said the sound coundn't be recreated. At 14k I checked my diff and it was 2 quarts low. I replaced the fluid and the noise is still there. I recently took it back in and the rear axle seal was leaking. They put the truck on the lift and ran it and didn't hear anything. They said the exhaust was to loud. I have a feeling it's an axle bearing. I hope you have better luck since I just turned 36k and my warranty is done.

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99 F-150 XL 4x4. Reg Cab Flareside 4.6 5spd, 3.55LS. gibson 3" cat-back, K&N Gen ll.Westin step bars.Ventshade window deflectors and bug deflector. rhino liner and a cool white shifter ball.

 

Harry, If your diff. was around 2 qts. low on lube, I think you need a new Ring & pinion & brg's. I would immediately go back to the orginal dealer that couldn't diagnose the problem & demand that they remove the rear cover. I think they will see "crows feet" imaging on the ring gear. "crows feet" is indicator of severe low lube failure. Also, try to find where the orginal source of the leak started. Be sure & insist that tech. flushes & cleans all derbis from axle hsg. assy. before rebuilding.
A good indicator of diff. & trans. failure: a leaky seal indicates contamination has worked into the component, contamination is working out of the component, or vibration is working on the component--making it leak.
Sometimes, in the casting process of axle housings, all the sand & slag does not get removed from the housing. This is a probable cause of a low mileage leaker (on a new vehicle). Also, if your diff. is limited slip, be sure they add fricton modifier to the lube--after rebuilding.


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1999 Teal Blue F-150 S/C
4.6L, XLT, 3.55 L/S 4x2
Tow pkg., Rhino liner, Engine block heater & Swiss hard toneau cover. Premium sound
255/75 R16 Generals-owl
This" is Mama's pride"

 

Gearmanx17 , thanks for more good info. Do you think excessive free play between the ring and pinion gears could cause a whining sound from the rear ? I checked the oil level and it is okay and there has been no evidence of leaks. Btw, my f150 is 2WD and does not have a LS rear axle.

 

Znstr, Are You sure the noise is coming from the rear? Have you rotated tires yet? If so, is the noise any different? I have seen instances when vehicle driver said he had a bad diff.--end up being frt. wheel brg. on 4X2. Have also had fuel problem blamed on bad trans. or diff. in large class 8 vehicles. Yes, alot of backlash (or slop), between ring & pinion can & usually will cause a whine.

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1999 Teal Blue F-150 S/C
4.6L, XLT, 3.55 L/S 4x2
Tow pkg., Rhino liner, Engine block heater & Swiss hard toneau cover. Premium sound
255/75 R16 Generals-owl
This" is Mama's pride"

 

Thanks for all the good info!!!!I will let you know what I find!!!!!

 

Capitan,

I have what sounds like the same truck, and I was getting a whine at about 45 MPH (68KPH) and seemed to be more pronounced under slight acceleration. Luckily, I have an extended warranty. I took it in at the beginning of the week, and guess what...... They had to change the ring and pinion set (twice) to get rid of the whine.... You don't want to know what it would of cost without warranty...... Let me know how you make out....

Rick