Well all of the sudden my rear axle has a whinning noise. Must be pretty loud because i can hear it over the annoying loud Baja claws on my truck.

I hear the whinnin noise when im going at a stead speed with a steady throttle. Once i let off the gas the noise goes away. Back on the gas and theres the noise again. Also noticed when i brake at a stop sign i get a clunk feeling in the seat.

Fluid is good.. U Joints are tight.. Im thinking pinion bearing or an axle bearing? Anyone ever have this experience before?

Could also be a u-joint on the driveshaft, that would be easier to change than a pinion bearing. How old are the u-joints?

Havent replaced them since ive owned the truck. U joints make a noise or aint it just a clunk when you take off? I checked em out and they felt great.

Depends on how they go, but they can definitely make a noise like what you're talking about, which can often times be the precursor to the "clunk bang CRACK!". Are they greasables or non-greasables?

Non greasable so they are obviously factory ones.. They are cheap and should be replaced soon. I guess il take the driveshaft off and put some new greasable ones in. And check to see if the pinion has any play in it while the driveshaft is off as well..

Non greasable does not mean they're factory. I just replaced mine with non greasables. They're stronger joints because they're not cross drilled for grease channels, and they seal in grease better because the greasables are designed to let old grease eek past the seals when you regrease them. Greasable joints often work well if you really keep up on greasing them-- but a nice set of Spicer non-greasables, though slightly more expensive than their greaseable counterparts, should last upwards of 30-50k miles or even more.

This is what I was told by a huge driveline outfit in Sac that does most of their work with big rigs and industrial applications. They had u-joints on display that were the size of the wheels on my truck. I was pointing to different joints-- "how much is that one?"

"that one would run about $10,000"






They were using a giant broken u-joint slip yoke as a table right inside the front door. If I trust anyone's word it's THESE guys-- they ARE driveline.

Ive never seen greasable and grease used so many times in one post... HAHAHA

Well then lol... What really dont make sense to me is how come theres no vibration?

Doesn't necessarily have to have a vibration. If you've got, for example, only 1 u-joint cap that is only STARTING to dry out, then the joint might very well still be functioning properly (not binding or locking up), but maybe that one cap is gettin' ready to call it quits.

I'd start by pulling the rear driveshaft and pulling the u-joints caps. It's a HELL of a lot easier than pulling your pinion only to find that the pinion bearing is perfectly fine, then having to reinstall the carrier + gears + axle shafts and have to shim to your pinion the proper amount and set the backlash and YADDA YADDA YADDA. Driveshaft removal = 4 bolts (6 for me because I've got a center support for my long ass driveshaft.... no I'm not trying to compensate Tony )

Deju vu Chris. Maybe we should play the lotto.


Chris and myself were just talking about non greasable joints on the phone earlier.

I only had a noise like that once and it turned out to be a bad pinion bearing, but I'm with Chris. Start with the simple stuff first.

surewhynot said:

Deju vu Chris. Maybe we should play the lotto.

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Yeah no kidding huh? And just 2 days ago I was talking to Chris (95F350XL) about it on the phone too

I only had a noise like that once and it turned out to be a bad pinion bearing, but I'm with Chris. Start with the simple stuff first.

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No doubt that it could be a pinion bearing... But if his u-joints have never been replaced then that would be a great place to start.

Mike-- I recommend Spicer non-greasables. Napa will sometimes carry Spicer joints if you're lucky. I believe this is what you want:
http://broncograveyard.com/bronco/i-32482_u-joint_3_7_8__dana_spicer.htm

I had a whine in my rear axle area and it ended up being the U-Joint. Usually your ring and pinion don't just 'unalign' after that many miles.

When it was my u-joint the whine would get higher and higher pitched until about 45 and then you couldn't hear it anymore.

Ryan

Thanks everyone for your replys! Im hopin that its just a U joint. After work tonite il take another look at it. Really cant fix anything untill the weekend.. But ive been babyin it.

It sounds kinda like the bearings in the axle to me... IDK though...

Ive myself never heard a U joint make that kind of noise ever but im hopin thats it. Tomorrow im going to take my rear driveshaft off and put the truck in 4x4 and see if i can still hear the noise..

95bronk said:

Ive myself never heard a U joint make that kind of noise ever but im hopin thats it. Tomorrow im going to take my rear driveshaft off and put the truck in 4x4 and see if i can still hear the noise..

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Just so you know, that test will not be completely conclusive. Removing the rear driveshaft will eliminate the u-joints from the equation, yes-- but it will also take the load off of the pinion. So if the noise goes away then you still won't know if it's the u-joints or the pinion bearing.

Yaa il have to take the rear driveshaft off n e ways so il just play around and see.. I understand what your saying tho

Noise diagnosis in a differential isn't a definate science. I would be leaning to a ring gear and pinion because they will usually show with noises changing from accel to decel. The reason for that is, because you use a different side of the gears when changing.

Went to my mechanic during lunch today.. He took it for a drive, put it up on the lift and checked it out. Said its not U joints. He said looks to be the pinion bearing because mine wouldnt be the first one hes delt with with the same symptoms.

So i asked him what should i do at this point? Find a used rear axle? or have this one rebuilt. He said for the low miles and condition of my truck it would be stupid to go gun ho and buy a used axle that you have no clue how many miles it acually has on it.. Which i agree. He said 500 dollars to have it rebuilt including parts..

Little does he know i get a great discount on autoparts and i can get everything needed to replace for around 70 bucks. So im gonna gather the parts this weekend and ask him how much he will charge labor..

Put it on jackstands today. I should get a sound clip of the rear axle when the truck is running and its idling in drive LOL! Sounds like a billion loose parts flingin around in there...

Im buying my cousins truck this weekend. He has a 94 F150 with the same rear axle code. Gonna swap them out this weekend as well as putting the nice and quiet all terrains on it. Cant wait!

yea definately the rear end..........500 to rebuild that axle is a little steep....