Hey all, I recently purchased my first JKU Sport a few months ago and it's basically stock besides a 2.5 lift and 35" tires. The first major upgrade I'd like to do is swap out the stock Dana 30 for a Dana 44 and I'm not sure how to go about it. I've looked into some drop in options like Dynatrac Prorock 44 and Taraflex, but those cost $$$. I like to explore my options on swapping in a junkyard axle or maybe finding a guy selling a Dana 44 from a Rubicon, but I don't really know how much of an undertaking that is. Any advice would be appreciated and if there are some existing threads on this send the links!

Thanks!

 

Junkyard 44's aren't really an attractive option for the JK (unless it's from a rubicon...), better off looking at 60's if you go that route. It's been a while since I paid attention to pricing on aftermarket front 44's, but I think the G2 Core and the Dana Ultimate were the lowest prices to be found at that time. Worth adding them to the comparison list, at least. And who knows, you may win the lottery and find a great deal on a used rubi axle, others have in the past.

Your current gears are 3.21, or 3.73? Remember that you need to match the gears in both axles, so you'll likely to be regearing the rear end to match the new front (or possibly regearing both). Aftermarket has the option for choice of gear ratio, but Rubi's will come with either 3.73 or 4.10, so make sure you verify which it is if you find one.

 

I'm pretty sure the ratio is whatever comes from the factory. Right now I'm running 35" tires and I could see myself moving up to 37s in the future. Is there a gear ratio that can run both those tire sizes well?

 

Heh. For non-rubicon, it is either 3.21 or 3.73 -- except for 2007, which had an option for 4.10 as well. For rubicons, they were all 4.10 from 07-11, then with the new engine in the 12+ models, the axles can have either 3.73 or 4.10. So again, you need to find out what your current gears are, and if you find a used rubi axle to swap in, specifically what gears it has. You don't want to shift into 4x4 with mismatched gears.

For the ratio, what year, and what transmission? Do a quick google search for something like "jeep jk gear chart", that'll give you some numbers to work with. Use actual measured tire height, not what the sidewall says or what the mfg lists in the specs. (my last set of 35's measured 33.5", and my 37's are around 36 measured...)

 

What do you plan to achieve swapping in a 44? If you plan to wheel the heck out of the jeep and that is why you want a D44, then I'd tell you you're really better off with that $$$ aftermarket housing. This is coming from someone that has built up a rubi 44 previously. Somewhere on here I added up all the figures to show someone why it didn't make as much sense as it does on the surface. The only time a rubi 44 makes sense IMO is if the gearing in it works for your build as a direct swap, which means either 3.73 or 4.10 if you can find one, and if you don't plan to go wheel harder things.

As far as the actual swap, it's a good days work if alone and working in the garage, but not too bad. Do it 2 or 3 times and the job gets old. I've done my last axle swap I'm gonna do.

 

Alright, so I called the dealership and based on my VIN I have a 3.73 gear ratio. I measured my tires and they're more like 33" not 35" and according to one of those gear ratio charts I really should at least be at 4.1, and 4.88 would be best. I don't plan on doing any extreme offroading but I'd like to be able to hit some moderate trails and do some rock crawling. I also could see myself moving up to 37" tires so I'm thinking that wheeling with 37s on a Dana 30 probably wont workout so well, right? But, good call on the rubi only being a better deal if its the same gear ratio.

 

You can hit moderate trails and rock crawling exactly the way the jeep is. No need to go to 37's and all of the cash that follows down the hole. It's better to use that cash, go wheeling more often, and build up your skill to where you can do just fine with what you've got. Despite what Facebook and the internet says, you don't need 37's and lockers to get down a rocky road with a couple of mud puddles.

 

Lots of people run 37's, or larger, on JK d30's. For some it works out, for others, not so much. Then again, there have been many bent/shattered front housings on smaller tires too. Luck of the draw kinda thing, but yeah, bigger means more chance of a problem, and smaller does not mean your axle is safe.

Unless the current lack of performance is bugging you too much, just stashing money away in savings for now may not be such a bad call. Then when you get to the point in your offroading that you want to tackle tougher trails and/or are ready to pull the trigger on 37's, you'll have that big pile of cash to drop on an aftermarket front 44 + a rear re-gear and locker - and you won't be kicking yourself for wishing you had gone higher numerically on the gears or finding yourself dumping a ton more cash into strengthening your shiny new stock rubi axle.

 

Good points all around! I'll hold off for now and do more wheeling to see how everything performs and decide on upgrades from there. It does seem like re-gearing would be a good idea at some point.

Thanks for all the help fellas

 

After what you described, this is what I would say. If you could find a set of Rubi 44s with 4.10 gearing, AND you would be content on 35s, that might be a good swap for the right price. You get a small bump in gearing and pick up two e-lockers. You'd still probably need to add c gussets and some decent ball joints at some point. Around my area, you can sometimes find a set of rubi axles for around $3k - $3500. Turn around and sell your axles for ~$1k - $1200 and you're in the upgrade for around $2500. Again, it only really makes sense if you are ok with the gearing, and I'd tell you that 4.10 with small 35s (measuring closer to 33), it's acceptable with the 3.6L, or at least around my geography it is (I've had 35s on 4.10s).

Just to expand on what I said above, what doesn't make sense is to buy rubi axles, regear, add gussets and a truss, and beef up the control arm brackets and shock mounts (you usually end up outboarding the shock mounts and can bend the factory ones...been there, done that). At the end of the day you end up with a low end locker and tubes that are no better than what you currently have. Sure, the D44 gears are larger than the D30, but if you can't weld and do all the work yourself, you end up having almost as much as that nice aftermarket axle that is much, MUCH better.

I agree with everything above. You should really just go out and wheel that thing as is. For what you described, you will be surprised what you can do. Honestly, everyone thinks lockers are the end all be all. If you get into technical rock crawling, they are definitely necessary IMO, but for most general wheeling, you don't need them. When, or even if, you start running into things where you get stuck cuz one tire just ain't moving, then you'll start getting an idea of what kind of traction assistance might make sense for you.

Under the modified sub-forum there is a sticky about 37s. Not everyone will find all of the points in that sticky necessary for their particular build, but they are all things to think about.

If you don't already have a winch, recovery gear might be a better use of funds up front.