Broken ARB spider gears: How bad is it?

TJ Mangler

New Member
Original poster
Joined
Mar 9, 2025
Messages
3
Location
New Jersey
Hello everyone,
New to the forum ,but long time lurker, and new to the TJ so I'll keep the story somewhat short:
Bought a '03 TJ w/ 154k miles. Drives great, runs great, frame is spotless (for the northeast). Spent the weekend replacing all the fluids she's got. Lastly I get to the Dana 35 rear diff and find this.

The one of the last 3 owners installed an ARB compressor and front/back ARB lockers on seemingly stock axles.
Aside from the dirty diff oil, it looks like the top and bottom spider gears are chewed up. Very slight amount of up down play with my finger but I'm unsure of what is tolerable. It also looks like a shim was spit out and was stuck on the right side of the diff housing. Cleaned it as best I could, removed the shim and the couple of metal pieces in the bottom of the housing, and put it back together for now. The really weird part is that the rear drives fine even in tight turns and isn't making noise - and how they chipped teeth and spit out a shim without damaging a stock axle is beyond me.

I know ignoring it wont make it go away and dont want to make things worse. The best I can tell is that the whole ARB carrier has to come out and needs ARB gears. If the diff was stock it would be a $100 for new gears and a 20 minute fix. I already have a ticket in with ARB for guidance.

What options do I really have? I do 80% road driving and 20% offroad (meaning hunting/camping access roads. No crazy rock runs).
I basically just need to fix the diff so I dont end of destroying the entire rear end down the line. I think a Dana 44 is overkill for my needs, and a Super 35 seems to be the only way to even think about running a locker - but if the axle is stock then a different locker would still needed for the 30 spine count 😢. I would say I'm a medium level mechanic but completely redoing the rear end seems to be just outside of my wheelhouse and garage space.

What are my options here to get the rear end serviceable? Keep driving like this? Any other options/fixes here I should consider? A full regear is a bit out of budget at the moment. I really am not looking for a locking diff at this point but more so want to be able to keep driving her and not have the rear finally grenade on a camping trip.

Thanks!

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I mean, if you don't use the locker, you're probably ok still using the stock 27 spline axles, but it begs the question as to how you grenaded the ARB spiders and didn't break anything else.

My grandfather had auburn gear ected selectable limited slip/lockers installed f/r in my jeep when it was his, and he somehow managed to never break a stock axle, and he would just flip the locker switch as soon as he hit the trail and leave them on until he was done. I honestly have no idea how he never broke anything doing that but it managed just fine in the end.