Is my tranny or differential broke? Options

[HardHead93]

The car has been leaking gear oil. I thought it was an axle seal so I took it to my local shop because they installed the original seal and would warranty it. Come to find out it is not the seal. The axle has some serious in and out play in it. When it moves out gear oil leaks out. The shop has tried 2 other brand new axles and the problem is the same. The last axle would not click and lock in. I have a helical LSD in an S54 transmission and I am running a Gen 4 3sgte tuned for 340 hp on E85. I track the car so it gets beat on pretty hard. The shop is having a hard time getting a good part number because the original part number is discontinued but superseded by another. One axle came from OReilly's and the other came from AutoZone. Is the tranny or the differential broke or am I not getting the right axle? Has anyone else had this problem?

[slavie]

Can you quantify "serious in and out play"? Also, I'm assuming we're talking driver's side axle since you mentioned the snap ring which is not present in the pas side axle.

Some in and out play is normal as there's some slop in the snap ring securing mechanism. Maybe about 1/8 of an inch.

With aftermarket axles, you MUST install a new seal with a new axle. OEM seal is much preferred - I've had aftermarket seals leak within weeks of installation. As you may have heard, quality control on aftermarket garbage is non-existent, and sometimes the shaft is slightly undersized. A new seal will wear to the shaft, if you will, and seal. If you then take a new, random-sized shaft, and the old seal that was previously working on a different sized shaft, you get a pretty massive oil leak - you'd be surprised just how much oil can leak past. We're talking puddles, not just stains under the car. Ask me how I know.

The fact that a third axle would not even snap in does not surprise me either. I've had aftermarket axles where the snap ring it would seem was bent out of some standard wire not treated in any way with no spring to it, and that garbage will deform and not go in when you try to insert it. I've had to remove original springy snap rings and put them onto brand new aftermarket axles.

TL;DR: Aftermarket garbage is the root of all evil and belongs in the garbage.