Gears and axles 2003 tj

[Luke VC]

So I have a 2003 Jeep TJ with the dreaded dana 35 and 3:07 gear combo ... right now I run 31's at's and its decent except for steep hills ... I am thinking of stepping up to a 33 x10.50 x 15 or a 34 x 9.50 x 15 mud or super swamper .... any real world experience with this ... swaps seem pretty pricey and wondering if they are as weak as everyone claims . More from a breakage with mild wheeling standpoint .. Thanks

 

[Graeman]

I would look for some used Rubicon axles for sale and swap them out. You will get stronger axles - Dana44, better gearing - 3.73 or 4.10 and factory lockers - air or electric for under $1000.

 

[Saints&Sailors]

33s will break a stock Dana 35 on the street (ask me how I know). Your options are as follows:

1. Purchase a "Super 35" or similar competitor product that replaces the axle shafts in your existing Dana 35 with shafts that are 30-40% stronger. This is your cheapest/easiest option.
2. Find a set of Dana 44s out of a Rubicon or a Dana 44 out of the rear of a TJ that came with that axle. This could be cheaper than option #1 but you will have a tough time finding parts - they are very few and far between at this point.
3. Bolt up a Ford 8.8. There are companies that make retrofit kits to accomplish this. This is the best option but it is also the most expensive. It'll take time but this is the best way if you plan to keep your Jeep for a long time. If you're racing rust or other mechanical issues. This is not a wise use of your funds.

The above options, depending on which one you choose, may or may not address your gearing issue as well. My old TJ had 3.73 gear ratios with 33" tires and it was a dog. I upgraded to 4.56 gears and, at altitude, it was still a dog. IMO, you're going to have to re-gear if you'd like to run 33s. The proper ratio will depend on whether or not you have (i) an automatic or a manual and (ii) the 4 cylinder or 6 cylinder engine.

 

[JDGreens]

Honestly the cheapest and worth while way to go. as you save up for re-gearing is to look for a set of axles (8.25 Chrysler) from and donner Xj automatic tranny. it will have 3.55 gears which will greatly improve your currant situation. you should be able to find them for about $350. That is what I did for my Xj. Make sure you get them from 1999 or older with a high pinion Dana 30. These axles would handle 33-35s if driven correctly. When I had 31's it was perfect. I put 33's on and yes I need to re-gear but it is manageable . Cheers!

Also I believe they would swap right in. no mods that I know of?

 

[Luke VC]

thank you all for the input ... the search begins

 

[smritte]

If you buy rubicon axle's. Your going to want to put some money in them. The front is actually a Dana 30 with a 44 diff. The axles are weak, the ball joints are real weak and the housing should be reinforced. By the time I was done with mine, I could have bought a nice custom curry or dynatrac. The lockers require around 10psi. Your best off getting the rubicon pump for it. I never broke one of the lockers but, the ARB's are much better.
The rear is not bad if you run a chrome moly axle. The gears are special also. The ring gears are thicker than normal. Fortunately their not hard to get.
They do come in a 4:10 ratio.
If you have someone who can mod them, the JK Rubicon axles are strong. They do run a few inch's wider though and wont just bolt up.

 

[MOAK]

I never broke one of the lockers but, the ARB's are much better.

Sorry man, everyone is entitled to their own opinions, There is a very good reason that you or virtually no one else has ever broken a stock Rubicon locker. ARB lockers are a very well built, very stout product, However, the Rubicon stock lockers are every bit as good as, if not better than the ARB units, unless one is into heavy duty rock crawling and huge tires, which I believe the OP is not.

To the OP, a lifetime ago I was in your very situation. I had a TJ with the very weak dana 35 with the 3.72 gearing. I wanted stronger and lockable axles. When all was said and done, it ended up being way less expensive, "over the long term", for me to sell the TJ and purchase a Rubicon with the 44s , 4:11s and lockers. That vehicle served us well for over 125,000 miles. I very rarely engaged the front locker and when I did I was sure to be going relatively straight. The front axle U-joints are the weak link on those jeeps and need to be replaced about every 50-75 thousand miles with normal use. If you're avidly rock crawling or doing a ton of deep water crossings than the carnage gets even worse and you'll be wanting to upgrade the entire front axle assembly. Having said this though, I eventually threw in the proverbial towel as it just isn't possible to modify a jeep to be a Landcruiser. We bought our cruiser then sold the rubi. I mentioned "long term" above because we sold the rubi for more than the cruiser cost, way more. TJ Rubies just don't loose their value. Nor do Landcruisers. Good luck with your decision.

 

[Luke VC]

Sorry man, everyone is entitled to their own opinions, There is a very good reason that you or virtually no one else has ever broken a stock Rubicon locker. ARB lockers are a very well built, very stout product, However, the Rubicon stock lockers are every bit as good as, if not better than the ARB units, unless one is into heavy duty rock crawling and huge tires, which I believe the OP is not.

To the OP, a lifetime ago I was in your very situation. I had a TJ with the very weak dana 35 with the 3.72 gearing. I wanted stronger and lockable axles. When all was said and done, it ended up being way less expensive, "over the long term", for me to sell the TJ and purchase a Rubicon with the 44s , 4:11s and lockers. That vehicle served us well for over 125,000 miles. I very rarely engaged the front locker and when I did I was sure to be going relatively straight. The front axle U-joints are the weak link on those jeeps and need to be replaced about every 50-75 thousand miles with normal use. If you're avidly rock crawling or doing a ton of deep water crossings than the carnage gets even worse and you'll be wanting to upgrade the entire front axle assembly. Having said this though, I eventually threw in the proverbial towel as it just isn't possible to modify a jeep to be a Landcruiser. We bought our cruiser then sold the rubi. I mentioned "long term" above because we sold the rubi for more than the cruiser cost, way more. TJ Rubies just don't loose their value. Nor do Landcruisers. Good luck with your decision.

Thanks for the response .... I have also shifted gears .... I just purchased a 2017 jku willys wheeler ... so the gears and axle situation has improved ... now to begin the build ...

 

[KonzaLander]

@Luke VC Congrats on the new rig!

I do want to add some information in case somebody finds this thread in a search. You can break a rear TJ Rubicon locker due to the integrated mechanical limited slip. This break was NOT the locking mechanism, it was the limited slip and the Jeep was running 37's with 5.13 gears. If parts were available for these lockers, I am confident I could have repaired it to like like new condition. The front TJ Rubicon lockers are more reliable since they do not have the limited slip mechanism.

 

[MOAK]

@Luke VC Congrats on the new rig!

I do want to add some information in case somebody finds this thread in a search. You can break a rear TJ Rubicon locker due to the integrated mechanical limited slip. This break was NOT the locking mechanism, it was the limited slip and the Jeep was running 37's with 5.13 gears. If parts were available for these lockers, I am confident I could have repaired it to like like new condition. The front TJ Rubicon lockers are more reliable since they do not have the limited slip mechanism.
View attachment 99724

Yup, 37” tires will do that, but then, that’s not “ overlanding” that’s just weekend wheelin on the rocks and having fun.. BTDT

 

[4wheelspulling]

Honestly the cheapest and worth while way to go. as you save up for re-gearing is to look for a set of axles (8.25 Chrysler) from and donner Xj automatic tranny. it will have 3.55 gears which will greatly improve your currant situation. you should be able to find them for about $350. That is what I did for my Xj. Make sure you get them from 1999 or older with a high pinion Dana 30. These axles would handle 33-35s if driven correctly. When I had 31's it was perfect. I put 33's on and yes I need to re-gear but it is manageable . Cheers!

Also I believe they would swap right in. no mods that I know of?

Many good suggestions. Along the same line as the above, look into a Ford Explorer rear axle Ford 8.8 with disk brakes, 96- 2001. I used a 96’ with disks on my build on my 95’ Jeep Cherokee. I went all out with upgrades, but did not need to. I found a low mile rear axle from a Mercury Mountaineer, same bolt pattern on wheels, 5x4.5. If you look up the Ford axle codes you could find one with even 3.73 gears and a factor limited slip rear like I did, for $175 . This axle is 1-1/2” wider than your stock Dana 35. It is a smiple up grade axle but would need to weld on new mounts to match you rear spring perches. Any questions just ask me! Vance.

 

[JDGreens]

Many good suggestions. Along the same line as the above, look into a Ford Explorer rear axle Ford 8.8 with disk brakes, 96- 2001. I used a 96’ with disks on my build on my 95’ Jeep Cherokee. I went all out with upgrades, but did not need to. I found a low mile rear axle from a Mercury Mountaineer, same bolt pattern on wheels, 5x4.5. If you look up the Ford axle codes you could find one with even 3.73 gears and a factor limited slip rear like I did, for $175 . This axle is 1-1/2” wider than your stock Dana 35. It is a smiple up grade axle but would need to weld on new mounts to match you rear spring perches. Any questions just ask me! Vance.

8.8 is another good choice. 4.10 gears w limited slip can be had. With minimal work. Probably the best route for the rear axle $$$$$$ wise.

 

[4wheelspulling]

Luke VC,
98’- 06’ TJs also could be ordered with a rear Dana44 axle. Also, 89 Limited Cherokee or with some tow packages have the Dana44 rear axle too. Vance.

 

[Billiebob]

So I have a 2003 Jeep TJ with the dreaded dana 35 and 3:07 gear combo ... right now I run 31's at's and its decent except for steep hills ... I am thinking of stepping up to a 33 x10.50 x 15 or a 34 x 9.50 x 15 mud or super swamper .... any real world experience with this ... swaps seem pretty pricey and wondering if they are as weak as everyone claims . More from a breakage with mild wheeling standpoint .. Thanks

I ran 33s, 3.07s in a YJ for 15 years. Nothing "dreaded" about it but I never used 5th gear in hi range. Still plenty of power in 1st thru 4th.

The beauty of 3.07s and 33s is 4LO. For my use, mostly forestry roads, logging trails in 4LO I could hit 60mph. The Jeep drove like a Mustang. If you want to climb a waterfall quite right, 3.07s must go. But there is a bright side too. Gear for what you will do and enjoy. Right now I have a TJR with 4.10s and 33s. I really wish it had 3.73s.

PS, with the D30/D35 combo, I had no issues. I sold it with 400K KMs and the driveline was original with exception of some u-joints. An idiot can break anything. But you said, mild wheeling so the D30/D35 should be fine.

 

[4wheelspulling]

I hope you have that luck, but my brother and many were not so lucky. Vance.

 

[Dilldog]

I killed the 35 rear in my TJ when it was on 30s... but then again the 4.0L makes peak HP at 4500RPM so its best to run it right at the rev limiter right?
But seriously, if you go easy on it you can get away with a lot, I have seen guys who are steady on the throttle wheel with 32s on the D35, but then theres guys like me that bounce it off the rev limiter on 30 and shoot gear teeth through the diff cover. A lot of it has to do with the driver.
But I will ask, why do you feel like you need that size of tire? It simply blew me away how capable a TJ is in stock form when you unbolt the sway bars.

 

[JDGreens]

I killed the 35 rear in my TJ when it was on 30s... but then again the 4.0L makes peak HP at 4500RPM so its best to run it right at the rev limiter right?
But seriously, if you go easy on it you can get away with a lot, I have seen guys who are steady on the throttle wheel with 32s on the D35, but then theres guys like me that bounce it off the rev limiter on 30 and shoot gear teeth through the diff cover. A lot of it has to do with the driver.
But I will ask, why do you feel like you need that size of tire? It simply blew me away how capable a TJ is in stock form when you unbolt the sway bars.

This is very true that those tires are more than adequate for your off road needs. I would say that being able to air down to 15 psi or even less in some cases, with a 33" tire make driving long distances on dirt road much more enjoyable.

 

[4wheelspulling]

Something the new comers to 4 wheeling, read and think is you need a longer wheel base to wheel. They do not understand that with a longer wheel base you need more lift, or larger tires to go the same places as a TJ with 98” wheel base can do stock. Yes, the longer wheel base will feel more stable going up and down steep hills. But does not mean the shorter wheel base vehicles cannot still do the same! The 4wheeling Magazines Of 20 years ago, would tell you that 100” wheel base is the sweet spot as an all around 4wheeling machine. A TJ Rubicon even a TJLJ Rubicon is hard to beat off road in stock form! Vance.