69 Chrysler 300 with 8 3/4, 2.76 Open Axle, 489 Third Member that was converted to a 3.23 Sure Grip. Four rebuilds in 2800 miles. I'm not sure which way to go at this point.
First rebuild
Convert the 2.76 open axle to a 3.23 Sure Grip. All the typical conversion parts from Dr. Diff.. A recommended muscle car shop did the rebuild. Car drove with slight gear whine, nothing bad. "Give it a couple hundred miles to wear in they said." While 400 miles from home on a Saturday, rear end starts clunking, making noise. I take it to the local Chrysler Dealership that happened to be open.
Second rebuild
Chrysler Dealership says, "I'm in luck. They have an old school mechanic that drag races Mopars and the 8 3/4 will be easy." Mechanic finds that the driver side axle bearing has failed. (Axle bearings were not replaced by the shop above, but they did have to pull the axles out for 3.23 conversion.) I can't prove if above shop messed up or the axle bearing just went bad. Dealership pulls and replaces both axle bearings, removes third member to check for any debris and re-assembles. Still a slight whine in rear end. Whine steadily gets worse. Dealership work is warranted, but 400 miles away.
Third rebuild
Local mechanic recommended by the local Mopar Club. Pulls rear end apart and finds Dealership installed new axle bearings without grease. Presumes whine was from axle bearings. Dis-assembles rear end, repair, replace, re-assembles axle. Still slight gear whine. A hundred miles later, clunking when turning left. Mechanic guarantees his work. Take car back.
Fourth rebuild
Mechanic feels the Dr. Diff yoke, ring and pinion aren't cut properly (manufacturing tolerance) and that's why continuous whine. Swaps out my 489 third member with a 742 third member that has original Chrysler parts in it. Dr Diff. Powr-lok Sure Grip still installed. Car no longer whines, but still clunks when making left turns.
All bearings replaced multiple times. What is my fix? Every "Expert" can't seem to get it right. I could have bought a brand new Moser or Dana 60 at this point. Frickin junkyard 8 3/4's run without a problem.
Disgusted!!!
First rebuild
Convert the 2.76 open axle to a 3.23 Sure Grip. All the typical conversion parts from Dr. Diff.. A recommended muscle car shop did the rebuild. Car drove with slight gear whine, nothing bad. "Give it a couple hundred miles to wear in they said." While 400 miles from home on a Saturday, rear end starts clunking, making noise. I take it to the local Chrysler Dealership that happened to be open.
Second rebuild
Chrysler Dealership says, "I'm in luck. They have an old school mechanic that drag races Mopars and the 8 3/4 will be easy." Mechanic finds that the driver side axle bearing has failed. (Axle bearings were not replaced by the shop above, but they did have to pull the axles out for 3.23 conversion.) I can't prove if above shop messed up or the axle bearing just went bad. Dealership pulls and replaces both axle bearings, removes third member to check for any debris and re-assembles. Still a slight whine in rear end. Whine steadily gets worse. Dealership work is warranted, but 400 miles away.
Third rebuild
Local mechanic recommended by the local Mopar Club. Pulls rear end apart and finds Dealership installed new axle bearings without grease. Presumes whine was from axle bearings. Dis-assembles rear end, repair, replace, re-assembles axle. Still slight gear whine. A hundred miles later, clunking when turning left. Mechanic guarantees his work. Take car back.
Fourth rebuild
Mechanic feels the Dr. Diff yoke, ring and pinion aren't cut properly (manufacturing tolerance) and that's why continuous whine. Swaps out my 489 third member with a 742 third member that has original Chrysler parts in it. Dr Diff. Powr-lok Sure Grip still installed. Car no longer whines, but still clunks when making left turns.
All bearings replaced multiple times. What is my fix? Every "Expert" can't seem to get it right. I could have bought a brand new Moser or Dana 60 at this point. Frickin junkyard 8 3/4's run without a problem.
Disgusted!!!
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