The flange that goes behind the fitting the rear u joint bolts to is loose (in front of the bearing on the drive pinion), and making quite a racket going down the road at low speeds. It just spins. Is this going to be a major problem...like I need to fix it now? Or can it wait a few months till I save up some money to fix it? The axle is in my '84 5th Avenue (yes, I know it didn't come with it, friend I bought it from put it in after the 7.25 went), and I don't drive it much.

Look at the casting numbers on the third member on the drivers side under the pinion gear and post the last 3 or 4 numbers, it makes a difference on how to fix it If the third member is NOT a "489" your in luck, if it is a "489" then it takes a little more work. Let us know which one you have

I'd b safe & sit on it till you can swap it out. Not sure if it could toss the shaft or lockup at speed but I'd get another sure grip coming & if there's any doubt about shavings I'd pull the end seals/clean the gear oil out & clean the housing but I'll defer to Kunkel for the final word

Its a 741. Came from a '69 Belvedere.

IIRC 741 has a solid spacer so the pinion can be R&R with out any trouble


are you talking about the pinion seal dust cap that is pressed onto the yoke?

I removed mine when I had my yoke off the 742 case fixing a broken bolt

just tapped it off with a hammer and put the yoke back on

a cutoff/whiz wheel can get it off without R&R of the pinion,thats what I would do

i would replace the seal if you do R&R the yoke also

good luck

Have you tried getting it back in, or can't you get to it?

If as we assume talking about the dust flange behind the rear pinion flange you could very easily fix that without removing it. Just hold in place and hit the pinion/flange join with a quick tack with a arc welder. Just a couple of very small tacks on each side will hold and doing it quickly will not create enough heat on the pinion to damage the seal or start a fire. You don't need much to hold it as it is not a loaded joint.