Faalin

Hi everyone

I have a 2014 JKU that i believe to be stock, it is running BFG KO2 285 tires. The driver side axle seal is leaking, since most of the axle will have to be take apart my thought was to re gear it. Would i have any issues with putting in 4.56 gears front and rear with 285 tires?

I was looking at Yukon gears as they have a complete kit with gears and seals for front and rear. In the technical notes it says "If you are running a 3.21 ratio you will need to purchase a new front carrier case with this package" I tried look on the internet to see what the stock gear is but couldnt find a definitive answer. Along with this i thought about replacing the drive shafts with Reel driveline shafts so i wouldnt have to swap yokes later on, i could do replace the yokes with the regear.

The game plan this summer is to put on 35's and a metalcloak 2.5 game changer lift.

Going to head over to a local shop tonight to get a secondary thought from them.

karls10jk

That's quite a stretch. I'd just replace the seals and be done. I can tell you that I've replaced seals a handful of times before moving to a regear. If you'd already planned on a regear and you're ready for that break in cycle as well as the costs associated then I say go for it, but from the simple standpoint of a leaking seal- just replace the seal and move on with life.

resharp001

In regard to the DS, you can get aftermarket shafts that mount to the factory pinion flange. If you do want to swap to a yoke, that is indeed the best time to do it. I’d keep the flange and leave the option to upgrade for later if the old DS craps out. I know Adams makes one for the flange and would think there are a few others.

Can’t recall if you are auto or 6-spd and it’s not in your profile. Running 4.56 gears with the current tires and the 3.6L auto is going to lean a tad aggressive (moreso if you have a 6-spd), running 2800-2900 rpm on the highway, but that is where some of us live all the time. It would be about perfect once you move to 35s.

You can do the ole rotates a tire and count driveshaft rotations to figure you’re gearing. You can also open the diff and count the teeth, or just eyeball your RPMs at 70mph and crossreference with the JK gear charts that are on the web. Highly likely you have 3.21 gears and need a new carrier, but that isn’t a lot of money…want to say ~$50-75.

If you do your own work, I’d be with Karl and say just swap those seals out. Few hours in the garage and a good learning experience. If you have to pay someone to do the work then I get the desire to knock out these planned upgrades as well.

Faalin

Jeep is indeed a auto, right now im averaging around 13-14 MPG on the highway so i would have to say anything is better then what i have now. A seal probably wouldnt be an issue, but im not really down for re gearing so a shop will be doing that, kind of why i was trying to get as much done as possible in one hit.

Im also in a time crunch as the jeep will be doing a 2600 mile round trip the first week of march, and i know if i re gear there is a brake in period.

So i guess i have a few options before the trip
Do nothing and watch diff level and suck up the gas millage
Re gear and stay on 33's
Re gear and move to 35's

karls10jk

As someone who just did a regear- don't expect your mileage to go up. I'm at the same or maybe a touch worse mileage because it runs at higher RPM's on the highway.

The seal is an easy DIY job with minimal tools, regear is certainly more complex. I think with the trip coming up, I'd just watch the fluid level.

resharp001

If you replaced the seals yourself right now, does that buy you 6 months and then you regear this summer with all the other stuff, or are you really angling to regear sooner and this is good justification? it's maybe a 3 hr job for someone that hasn't done it I'd say. If a $20 seal and couple hours buys you 6 months of parting with bigger money, just swap it out. If you really want to regear sooner, just monitor and put it off. If it's just flat on pavement you're not losing too much.....not like being in a steep off-camber angle where all that oil is sitting on the seal.

Faalin

Any work by me on the jeep has been halted by mother nature, i dont have a garage so all work is out in the driveway and well its 30* and 5 inches of snow on the ground. Looking at another 10" over the next 4 days and single digit temps. The ultimate goal is for gears, 35's, and a 2.5" lift but i can wait a few months and milk it by i can do that. Just figured if your in that deep might as well kill two birds with one stone and replace gears while fixing the seals.

karls10jk

They sort of coincide, but replacing seals is easy without damaging the gears or even touching that can of worms. The carrier with gear set comes out but it slips back in without any adjustment or time taken to shim it. You should be looking at a reasonable cost if you were to do seals only.

When you get to having the seals done- I'd insist on the new style seals. They're pricey from Mopar but worth the cost if you can find them elsewhere (drivetrain america had then). Shipping was a little more pricey but I ended up buying 4 seals so I'll be set for two changes. The older style seals are included with Yukon's kit but they don't seal as well, in my opinion.

Mr.T

If it's a small leak, I'd try adding Hapco pro-seal, or similar. If the leak happened right after putting in an axle, it may have a scrape -- But if it's age related shrinkage, it will probably do the trick.

Faalin

For right now i'll let it be and reassess the issue in he spring time. The end of the axle is wet but i havent seen any oil spots in the driveway, I did replace the diff oil in the front and rear a few months ago. The front i could not feel any oil when i stuck my pinky in the fill hole before draining it. I do have my first aid kit of tools and oils in the jeep so ill just keep watching and see how it does on the trip.