Hot Rods Loose Pinion Nut - Got Lucky

I had some bad noises coming from the rearend on my 52 Chevy Ute; with a 235/T-5/56 Chevy car rearend drivetrain. Ironically coming back from the scrapyard after unloading some scrap batteries and some copper plumbing parts.

I wasn't sure if a U-joint had gone out, or something inside the rearend like a bad pinion bearing(s). Would be fine on accelerating or cruising, but then bad noise when let off. U-joints were OK, so I proceeded to take the rearend apart: remove wheels and brake drums, take axles out, remove center section. To make long story short, it turns out the pinion nut had backed off maybe 1-2 turns. I cleaned up the inside of the housing, not much metal at all. With the center section on the bench I tightened up the pinion nut to get proper drag on bearings. Staked the nut well to hopefully prevent recurrence. Being an unknown lots of miles gearset and bearings, it has more backlash, but the wear pattern on the ring gear and pinion seemed OK. The differential carrier had the end of the pinion gear wearing into it from the loose nut allowing it to travel back and forth some. Just cleaned that up a bit with grinder to deburr, and then fully cleaned the center section assy.

Put it all back together and test drive result in no gear whine or bad noise. Some excess play from the backlash, but that's expected. So got lucky with not needing any new parts, just labor and couple quarts of gear oil. This rearend and entire drivetrain is on limited use anyway as I plan to swap 394 Olds, manual trans, rearend and suspension on a bigger project level build starting next year.

I can't really say why the pinion nut came loose? By staking it, I should keep that from happening in the future.

 

Maybe someone replaced the seal in the past and reused the same nut?

 

Had that happen after a gear change on an OT truck. New nut backed off. Used the old nut. At home the only way to tighten the nut was with a floor jack one notch at a time on a 12 point socket. Wife was a good sport and worked the jack. Never came loose again.

 

If there would have been worse damage, I would have just got another used center section. My current one is just a 3.70 open, nothing special.

I did consider making mine a Lincoln locker but wanted to ensure it was OK not going to make noise. Not like the mighty 235 needs more than 1 wheel traction

 

You could have used either blue or red loctite to insure the nut wouldn't come loose..... Surprised you didn't destroy a bearing