hey all. new to the forum. a few weeks ago i noticed that the center of my rear axle was dripping(the differential i think) and a few days later i began hearing a high pitched noise whenever i took my foot off the gas and began to decelerate. I dont hear the noise when accelerating at all, only decelerat. Any suggestions? my uncle thinks it has to do with the spider gears(???) and i was wondering what the leak might be and how much it might cost to repair. i have a 2001 f-150 6 cyl 4.5L 2x4. Thanks.

 

i would start by pulling the cover, draining the fluid, filling it back up again, and see if that helps any. The cover's seal may have failed, and may be causing the leak. this is the only way to fix it. if, upon draining/refilling the diff and resealing the cover you still experience whining, you may be in for a ring and pinion R+R.

 

A quick fix would be to tighten the nut in the companion flange.
No it is not the so-called spider gears.
Tighten the nut until it takes about 14-inch lbs. to turn the flange with the hubs off. That will take about 250 Ft lbs of torque, keep checking the 14-inch lbs as you tighten the nut. Do not over tighten.
You may want to replace the seal first for the leak but it might stop leaking when you tighten the nut.

 

about how much would that cost?

 

There is nothing wrong with your ring and pinion. They are a little out alignment with the nut loose.

 

you will be able to save the gears if you quit driving it, they are wearing a new noisy pattern right now, if the leak is coming from the pinion seal its most likely b/c the pinion bearing is gone and has beat up the seal. It needs bearings, a crush sleeve, and pinion seal. a pinion kit is what you would need, like this http://eastcoastgearsupply.com/i-127...stall-kit.html. as stated above new bearings and seal need to be installed, and the crushsleeve crushed to 14inch lbs preload, this is best left to a competent shop, shoud be done for around $200 dollars or less. anymore and they are overcharging you due to there incompetence take it elsewhwere. tightening the nut is like putting a band-aid on a gunshot wound. even if the bearings are not shot a crush sleeve and a new pinion nut properly torqued and locktite'd is the proper fix that will last longer than a few months.

 

its been sitting in my driveway for 2 weeks now

 

My truck was making that noise from rear end when I bought it. So I got the truck at a reasonable price. I went to my local auto parts store and bought a $100.00 bearing/seal kit + axle bearings and seals. Put all of the shims back in the same place they came out of, put torque to 28 inch lbs (new bearings is 28 and for used bearings 14).
That was 60,000 miles ago and it is still running like new with no noise.
Note:
Shims are for the axle housing and not the bearings or gears. So if it was set up right by FORD at the factory and nobody has been in there and you put all the shims back in the same place and side they came out of you do not need to have any special tools to put it back together. Do not forget the pinion shim.
Make sure you mark each shim (side) when you take it out. I also mic each shim and write down the measurement.
Be carefull not to break the side shims when you take them out and drive them back in.