So the car is a 84 Hurst Olds, doing some work on the rear brakes and suspension, wanted to pull the axles, open up the rear and I see this ... only half the bolt is in the posi carrier. Any suggestions short of cutting out the preload spring to get to the C clips?

 

They make an extractor kit
https://www.freedomracing.com/dpk-01...UaArbKEALw_wcB

 

Luckily, the way you access it has the cross pin in a great spot to help aid in getting the pin end of that screw out. This is an 80% probability issue with many of these rears and nothing unexpected. I bought a GM box full of those retainer pins for this reason alone.

There's been shade tree mechanics tell me that they simply busted out the cross pin with a small sledge and hammered on the end of the cross pin with a brass drift. I highly don't recommend that at all. Don't listen to anyone that's not a body man talk about taking a hammer to your car parts.

If you take the weight of the cross pin off what's left of the screw by getting the cross pin as horizontal as possible, you MAY be able to fish it out with a skinny magnet. I've been lucky 3 times already doing this very thing. It always seemed to break at the last couple of threads right before the pin on the retainer screw. Because it now should be well lubed, they were easy for me to coax them out with the magnet. I simply wiggled the magnet to help the busted piece along since it wasn't tight in the threads and I guess I was lucky.

If you don't mind cleaning up a few drill shavings, get one of those extractor kits as mentioned. I'd stuff the area around the case with towels or something before drilling to prevent shavings from getting everywhere. Just in case.

 

Thanks, ordered the Extractor kit and an NOS bolt, hopefully it comes out easily with the kit.

 

This is unfortunately a common problem on these axles.

 

Just wanted to post a reply and say thanks to all the Oldsmobile people on this site, Always helpful with advice and knowledge. The tool worked excellent!!!! Removed the bolt like butter. ... "I love the smell of differential fluid in the morning, smells like victory," hahahaaha

 

Every one of those things I ever worked on broke the retainer pin trying to get it out. And GM stuck with them for way too damn long IMO.

Even my 1976 Ninety Eight has a factory installed C-clip rear. If it gives me trouble I won't hesitate to put a 1971-75 rear end in it. The BOP and Ford design is far superior. There are reasons people install 9" Ford rear ends in GM cars, and why drag racing organizations require C-clip eliminators in some classes.

When I was in auto tech school in the 70s a graduation requirement was rebuild and set up a rear end. School had cores to practice on but a school buddy had a 70 Chevelle he decided to change from 2.76 to 3.55 gears. Instructor paired me with him. This boy lived 30 miles from the community college and had a grocery store job at night so the job had to be completed for him to make work that night.

We started the job at 8AM and when he tried to remove the pin it broke. He was a quiet boy but when that pin broke he turned the air blue. Mr Comer came running over "Boys, boys, what? Mason never carries on like that!" We showed him what had happened and I'll never forget Mr Comer saying, as he often did, "Not a problem. We have a tool for that!" Mr C went to the toolroom, told the student working tools that day he needed the extractor kit and where to find it. We finished the job in time for John Mason to drive the Chevelle to work that night.

He went on to work in a local race shop specializing in, you guessed it, rear ends. And still doesn't like Chevy C-clip rears.

When Mr C died, hundreds of his former students were at his memorial service. A top-flight mechanic, an incredible teacher and a good man who left his mark on a lot of kids who were trying to find their direction in life.

 

Every company uses the same retaining screw in pin FORD and Chrysler dodge etc. THey all use the retaining pins...SAME exact size,.
Just more people rebuild GM because they are good enough to get rebuilt...Ford and Chrysler you throw them away...LOL