R&P failure, what caused it?

[TJeeper]

A friend with a stock D30 was out playing in some big rocks, and blew a stock u-joint. This took out the stock outer shaft. They replaced the shaft, then found out the r&p was broken. After pulling the cover, they find 6 teeth broken off the ring gear.

This particular gear set was installed last fall. 4.56 ratio, an ARB was installed the same time. I think this was the first time it was taken off highway.

I'm trying to figure out how it broke. I have heard of people breaking 760 u-joints (this was a 297), hubs, and chromoly shafts before sheering teeth off the ring gear. Anyone heard of this, or is it possible it was a poor install?

[mrblaine]

Originally posted by TJeeper
A friend with a stock D30 was out playing in some big rocks, and blew a stock u-joint. This took out the stock outer shaft. They replaced the shaft, then found out the r&p was broken. After pulling the cover, they find 6 teeth broken off the ring gear.

This particular gear set was installed last fall. 4.56 ratio, an ARB was installed the same time. I think this was the first time it was taken off highway.

I'm trying to figure out how it broke. I have heard of people breaking 760 u-joints (this was a 297), hubs, and chromoly shafts before sheering teeth off the ring gear. Anyone heard of this, or is it possible it was a poor install?

There's no way to really know. Typically a blow u-joint won't take off ring gear teeth, but it's possible.

Any idea as to exactly what he was doing when it broke. Low or high pinion?

[TJeeper]

Low pinion, coming off a rock, steering turned 1/2 way, locker on. I am guessing this u-joint was probably on its way out and the stress at the moment is what caused it to break. She is not too mechanically inclined, I doubt she inspected the u-joints before the run.

[Matt Pascoe]

Do you know what brand the gear set was?

[TJeeper]

She does not.