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So after 60k miles my rear axle is junk.
While cruising at high speeds, the rear end started making noises, and once I stopped checked for leaks and or loose Pinon, it began to make the dreaded skip-a- broken-tooth-clunk-sound🫨
I removed the rear driveshaft ( out of precaution to the rest of the drivetrain) and limped home in 4H front wheel drive.
durring removal I was surprised to find the outter diff cover bolts had become looss
...after disassembley, I found what I had suspected, the 40s, 5.38 ratio, towing, and heavynlead foot are just TOO much for a OEM m220.
the case flexed under heavy loads enough to cause gear deflection....the ring gear moved away from the Pinon and overloaded the side case bearing causing it to spin the race. thos damaged the inside of the housing and caused slop in the ring gear (the ring gear and diff moves side to side nearly a 1/4" now) Obviously this much deflection cause the contact patch to run way nean the edge of the tooth and broke several off under acceleration.
while removing the parts I also discovered that BOTH the axle bearing races had also spun in the housing!!! I believe this was caused by tall tire leverage or bending moment under acceleration while side loaded. (hard corner G forces)
I feel the OEM axle is plenty strong (especially the shafts) for tires up 38"....beyond that the limits are found quickly. I have also confirmed this with mechanics, at 4x4 repair centers, that see M220s in Jeeps consistently with the exact same issues.
While cruising at high speeds, the rear end started making noises, and once I stopped checked for leaks and or loose Pinon, it began to make the dreaded skip-a- broken-tooth-clunk-sound🫨
I removed the rear driveshaft ( out of precaution to the rest of the drivetrain) and limped home in 4H front wheel drive.
durring removal I was surprised to find the outter diff cover bolts had become looss
...after disassembley, I found what I had suspected, the 40s, 5.38 ratio, towing, and heavynlead foot are just TOO much for a OEM m220.the case flexed under heavy loads enough to cause gear deflection....the ring gear moved away from the Pinon and overloaded the side case bearing causing it to spin the race. thos damaged the inside of the housing and caused slop in the ring gear (the ring gear and diff moves side to side nearly a 1/4" now) Obviously this much deflection cause the contact patch to run way nean the edge of the tooth and broke several off under acceleration.
while removing the parts I also discovered that BOTH the axle bearing races had also spun in the housing!!! I believe this was caused by tall tire leverage or bending moment under acceleration while side loaded. (hard corner G forces)
I feel the OEM axle is plenty strong (especially the shafts) for tires up 38"....beyond that the limits are found quickly. I have also confirmed this with mechanics, at 4x4 repair centers, that see M220s in Jeeps consistently with the exact same issues.
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