Well this isn't right...

[SRSslpr]

Having some issues with my ford 9inch rear end. I've got a 67 swb f100 with a 351w and t19. Whenever I move the truck at all there is a loud clanging noise from the rear. Rear end has fresh fluid in it but I'm not sure how long it has been empty not do I know how the truck was driven when the fluid was low. Just recently bought the truck in march of this year and have not driven it at all until now. I finally got a video of it which shows the driveshaft physically bouncing due to what looks like the pinion gear binding up and then shearing loose. Anyone have thoughts on what is causing this?

[][/url]

[sargentrs]

Ouch! Sounds like a shot bearing, either pinion or carrier, but could be a broken axle or axle bearing. Jack up the rear, both wheels off the ground, and spin one wheel, then the other and see if it's coming from one side or from the center.

[SRSslpr]

That's the weird part, when it's jacked up and I spin the wheels there is no noise. Have removed both axles and they both look fine; nothing broken.

[cep62]

[quote="SRSslpr"] Have removed both axles and they both look fine; nothing broken[/quote

]You can have a bad diff and your axles can be fine.
Check your u joints .
then pull your axles and take out and inspect the differental.
If it's never been apart you'll have chisel off the copper washers.

[chad67]

When you jack it up and spin the wheels, is the driveshaft spinning? If not you are just rotating the spider gears inside the differential. To get the driveshaft to spin, one wheel has to be on the ground while the other is spun, or a helper has to hold the other wheel still. If it was run without fluid, rebuild it no questions asked. It doesn't take long for dry gears and bearings to get galled and gouged beyond belief.

[SRSslpr]

Finally got a chance to tear apart my rear diff. What I found was absolutely awful. There was about a half inch of sludge inside the bottom of the diff. It had the consistency of melted chocolate. Had to literally scrape it out.

[URL=http://s190.photobucket.com/user/s ... .jpg[/img][/url]

Not only that, but there were chunks missing out of both the ring gear and pinion gear. Parts of the pinion gear were also almost worn down to nothing. No wonder this thing was clunking.

[URL=http://s190.photobucket.com/user/s ... .jpg[/img][/url]

[URL=http://s190.photobucket.com/user/s ... .jpg[/img][/url]

[URL=http://s190.photobucket.com/user/s ... .jpg[/img][/url]

[chad67]

Axle fluid, front and rear, is one of the most overlooked maintenance items. Most people don't give it a second thought until the noise starts. I think yours was the ring and pinion gears jumping each other. You were looking for an excuse to upgrade gears and go to a locker, right?

[two-bit]

Oh my....
I only thought our off-road rigs did that kind of damage.

Thats everything man. Bearings, shims, ring and pinion, the works. Trust none of your old parts, get them all checked out. ie: axle shafts, and housing.
Most of our off-road rigs do damage to the splines on the shafts when everything runs that hot.

Good luck with it.

Two-bit