Hey all,

So my 2015 JK currently has a rear axle seal leak on the passenger side. Originally I thought of just replacing the seal under warranty, but I might not be covered and I am also having a hard time finding available labor to get that work done. I'm hesitant to try a new mechanic for this work.

I am now considering going to one of my local Jeep guys to just upgrade some stuff. I know the all encompassing upgrade would be; New axle shafts, re-gearing and lockers. However, that is a hefty price tag and I know I can't afford all that right now. So I am asking if there is any benefit to just upgrading the shafts and gears and not doing lockers yet.

I'm currently driving on 35's with a 2.5" lift but I plan on moving to 37's when the time comes. This is my daily, but I do light trail rides and some overland camping. I don't need to build a rock-crawling beast but I'd like to potentially upgrade some components while the time calls for it. I know I'd be paying for labor again to have lockers installed, but maybe I can tackle that myself by the time that comes around.

Any help/tips are appreciated.

 

I am not sure why you want to go 37's as the drag they create is quite large compared to 33/35's. And the extra fuel consumption. If you do gears and no lockers then go back in to add lockers you still need to setup the gears again so double labour effort in each diff. If you can live with this then go ahead with your plan.

 

I mean I'm not set on any decisions as of right now, just trying to gauge what type of upgrades are necessary.

I currently have a busted rear axle seal so I was considering upgrading the shafts in the rear instead of just replacing the seal. But looking at it more it looks like if I'm paying for labor, it really only makes sense to install new shafts, gears and lockers all at the same time. I don't really need lockers right now so I guess re-gearing has to wait until I can afford everything.

I'm a novice with all this and just trying to learn the right way. I'd like to say that maybe I could install lockers by myself later down the line so I wouldn't have to double dip on labor but who knows. I'm even considering just replacing the rear axle shafts myself and calling it a day.

 

As Sixty mentioned, you will be setting up the gears (again) when the lockers are installed. This applies to any of the full-case lockers or limited slips. You might do some reading on 'lunchbox' lockers, which are easier to DIY in the driveway with no gear setup vs the full-case variety. But I assumed you were referring to selectable lockers, so...

Do some more research and see if you want to tackle gear setup along with the locker install. There are plenty of write-ups and videos to browse through to get a better idea. Or, plan on paying that labor twice. Or, just do the shafts and wait to have gears/lockers done at the same time. Or? Paying twice sucks, as many of us know first-hand, so good luck with the decision.

 

I definitely don't want to double dip on labor and I am fine with waiting for the right time to do an upgrade. I think I would try and upgrade the shafts myself now and then re-gear and install lockers down the line.

Just a few things regarding the shafts. Do you think I should spend money upgrading the shafts in the front D30? A few people have told me to just scrap the D30 and upgrade to a D44 up front as well. I don't offroad this very much and it's my daily driver so I wasn't sure how necessary an axle replacement is or if I can get by with the D30 and upgraded shafts.

 

If you think there is any hint you go to a locker in the rear in the future, there's no sense buying new rear shafts right now. You'd buy new 30 spline shafts and then the locker you buy later will be 35-spline....requiring 35-spline shafts. Just buy a new seal and pay a couple hundred or whatever to have it replaced. You could even pull the shaft out yourself and take it somewhere to have the seal and some new bearings pressed on. Not to be a downer....but if you can't pull the shaft and replace the seal yourself, then you are not likely to install a locker and set up the gears at that time. That's just kinda the reality. I would just fix the seal for right now and continue saving for bigger upgrade in the future cuz locker, gears, and new shafts will all be one big shebang.

I wouldn't worry about the shafts up front either. It doesn't sound like you're doing really hard technical rock crawling that is putting a lot of stress on those, and without a locker up front creating additional stress they are likely fine for what you're doing. Keep in mind that any upgrade to a D30 is typically moving the weakest link more inward, and the further out the weak link is the easier the fix. If you do happen to break a front shaft that is an easy thing to swap out. Grind up a pinion or ring gear and it's more painful. The max I would do on a D30, if it suited the need, would be regear and C gussets. If any traction control was needed likely a limited slip. just my opinion.

 

For what you are doing, don't move to 37's. 35's are more than enough tire for your description. 37's cost money to properly run right and while you can go cheap up front, you will pay more in the end. I would not put a dime in a dana 30. Changing that rear axle seal is like a $15 part and maybe 2 hours to do it yourself since you have never done it before. Take off wheel, remove brakes, remove the 4 nuts on the backer plate, pull the axle out, press off the bearing, remove the old seal, install the new seal, press the bearing back on and reinstall the axle, brake, and wheel. The hardest part is getting the bearing off the shaft but is not that big a deal if you have the right tool.

 

Hammer, cloth and anvil gets the bearing off. Wrap the bearing with the cloth, anvil is the backing piece and beat the hell out of the bearing. It shatters in the cloth and voila. Done it many times and once in the bush using a short piece of railway line for an anvil. Cold hammered the new bearing on with a pipe. Took a while but got him home.