A super 35 will solve the issue but again I believe for your uses the stock shafts will hold up just fine on 33s assuming it's not locked.
https://wranglertjforum.com/threads/will-a-dana-35-axle-handle-33-inch-tires.19832/
What gear ratio should I install in my Jeep Wrangler TJ / LJ? (and other re-gearing FAQs)
- Thread starter Chris
- Start date
https://wranglertjforum.com/threads/will-a-dana-35-axle-handle-33-inch-tires.19832/
If I understand correctly if I wanted to install a locker I should do the Super 35 if I don’t it should be good with the stock rear end with and 33’s
If you do decide you want to go with a locker, you might want to explore other options than a Super 35 kit, unless you're planning on doing the work yourself. Not knocking the Super 35's strength, but a 44 with alloy axles is stronger than a Super 35 with alloys.
For the cost of the Super 35 kit and install you're not far off $ wise to putting in a G2 44.
Question about tire diameter in actual use. 33/10.5/15 BFG KM3's are actually 32.5. Seems like most tires are at least a 1/2" smaller than their advertised diameter. That's not measured diameter but the numbers from https://tiresize.com/calculator/ when you go to individual tire spec's. Measuring the diameter, makes them even shorter. When driving at 70mph does the centrifugal force on the rotating tire stretch them out to a figure closer to their nominal size or is the measured diameter more accurate?? Grim Jeeper's site allows you to input tire size to the second decimal so calculations vary from nominal tire size, to Tiresize diameter to measured diameter at rest.
In any case, it looks like 5.13 is the gear for 32" tires for the Dana 30 limited jeeps running a 4.0/42RLE. Even then you are only running 2600 rpm at 70.
In any case, it looks like 5.13 is the gear for 32" tires for the Dana 30 limited jeeps running a 4.0/42RLE. Even then you are only running 2600 rpm at 70.
The measurement you care about for the calculators is the height of the hub from the ground x2. Any other measurement will not give accurate results.
33s will measure out to about 31.5".
35s will measure out to about 33.875".
In answer to this part of your question. It depends on your tire width, wheel width, and air pressure, yes, highway speeds can cause your tire to crown in the center, it's not by much, but it can.
If you run a 12.5 tire on a 8 wide rim with low enough pressure to have a flat contact patch while at low speeds/stopped, it will crown slightly at freeway speeds. If you run too much pressure it will crown all the time, that's the nature of wide tires on narrow wheels.
Recently got a TJ. Looking up the factory specs, (vehicle was 100% stock) it shows 30” tires but this post suggests a different ratio. Has 30” tires currently, just trying to make sense of this…
At some point I would like 32” tires so I’m just trying to figure out what gear ratio would work best.
05 Rocky Mountain Edition
4.0L I6 Auto
At some point I would like 32” tires so I’m just trying to figure out what gear ratio would work best.
05 Rocky Mountain Edition
4.0L I6 Auto
Since the 42RLE has such a high (lower numerically) overdrive it is typically recommended to gear taller. So even though you had 3.73 or 4.10 out of the factory most would say it wasn't geared right.
If it was me, I'd gear it as tall as possible, 5.13 or 5.38 (rubicon).
@Chris has had a few jeeps with 42rle's so I'm sure he has an opinion as well.
Seems the consensus is that factory gearing isn't correct. Anyone know why the engineers went with these ratios?
Lower production costs by not gearing for all transmission options. That is the only way to explain how the Rubicon with 5 and 6 speed manuals and the 4 speed auto can all come off the assembly line with the same 4.10 gear ratio. It had nothing to do with the appropriate gearing.
Gearing and axles are the next step in my TJ build. Based on information from this thread and others my current thinking is to just have a shop change out the 3.07 gears to 3.73 but I wonder if the stock Dana 35 (re-geared to 3.73) will hold up in all situations (e.g. recovery pull, or getting unstuck). Also, I think that 4.10 will be too low based on mostly highway driving and low chance of tires larger than 31”.
Current set up:
-2002 Sahara, 4.0L
-32RH 3 speed auto
-3.07 differentials
-2” ProComp/Rancho suspension lift
-31x10.50-15 tires
Anticipated use:
-70% highway (60-70 mph)
-25% in town
-5% off pavement: Florida sand, mostly flat with a lot of soft sand, some packed sand and occasional water puddle in the road. Very few obstacles and almost no rocks (this is Florida).
-We enjoy riding through the woods not mudding or hill climbing. There are some washouts on the roads but I am light on the skinny pedal.
*Note: Some might call this my DD but my DDs are a Triumph Bonneville T100 and Suzuki V-Strom 650XT (my two-wheeled Jeep). The TJ is for when my wife goes anywhere with me or solo trips when temps are below 30F, above 90F, if there is rain at time of departure, or I have multiple stops in town.
Future build plans?
-95% chance that this regear/axle build, and a winch, will be the end.
-4% chance that I add ½” body lift and 32” tires.
-1% chance that I install 1.25” body lift and 33” tires.
Current set up:
-2002 Sahara, 4.0L
-32RH 3 speed auto
-3.07 differentials
-2” ProComp/Rancho suspension lift
-31x10.50-15 tires
Anticipated use:
-70% highway (60-70 mph)
-25% in town
-5% off pavement: Florida sand, mostly flat with a lot of soft sand, some packed sand and occasional water puddle in the road. Very few obstacles and almost no rocks (this is Florida).
-We enjoy riding through the woods not mudding or hill climbing. There are some washouts on the roads but I am light on the skinny pedal.
*Note: Some might call this my DD but my DDs are a Triumph Bonneville T100 and Suzuki V-Strom 650XT (my two-wheeled Jeep). The TJ is for when my wife goes anywhere with me or solo trips when temps are below 30F, above 90F, if there is rain at time of departure, or I have multiple stops in town.
Future build plans?
-95% chance that this regear/axle build, and a winch, will be the end.
-4% chance that I add ½” body lift and 32” tires.
-1% chance that I install 1.25” body lift and 33” tires.
Dana 30/35's came stock with 4.10's in the 4 cylinder manual jeeps. I would have zero concern with the strength of the Dana 35 for the use you described. The dana 35 becomes an issue when you lock it then try to climb something and start hopping.
As far as gearing goes 3.73 will be perfect unless you jump to 33s. In that case, you'd want 4.10.
If you want to save some money I'd bet you could find a set of takeoff 30/35 geared to 3.73 for significantly less than a regear...
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Thank you for the confirmation about the Dana 35 being strong enough for my use.
How often do the 3.73 axles come up used? I've been searching FB and CL? What should I look for when buying used axles to make sure I'm not buying a problem? My wife is more comfortable spending the money to re-gear my 78K miles axles than buying used, how might I assure her that the risk is low going used?
It's a combination of regulations and sales gimmicks. They often sell you with one that's geared correctly in ads and then for MPG standards they do some bogus testing and yeah running an empty Jeep in a way that it won't be driven will give you pretty impressive fuel economy at like 55 mph. I don't know the tests, but they aren't how most people drive. And that kind of gearing is pretty bad off-road too.
I get really picky with manuals and gearing, because most OEM choices completely remove the ability to use Cruise Control and an OD and I don't like shifting a lot on the highway. Autos in a relatively loud vehicle probably isn't a big deal because you aren't the one shifting and the transmission is just compensating for the proper gear ratio until you start going down hill, it'll go into OD and then it'll shift out of OD once you're on flat ground.
What really grinds my gears though are 3.07s and an AX-15.......Why? It's just not right....It just means you own a 4-speed manual for almost all practical purposes. Though with factory tiny tires, technically it'll maintain speed on flat ground in 5th, but not well. However they can then justify to put like 19 mpg on the sticker or whatever they put.
Around here they come up every month or so. I don't know know about your location though.
I think I saw on Craigslist there is a dana 44 rear end in Tampa geared on 3.73 for under 1k. That almost seems like a break even with a regear (rear portion) then you could just get the front 30 redone.
Anyways. For any used axle I'd want to take the diff cover off and inspect the ring and pinion for any damage / confirm there is no metal chunks or water present. Besides that check if the tubes are bent or if the wheel bearing sound good. When the diff cover was off I'd also check the parts number to confirm the gears are what they said they are.
Finding 3.73 axles is hit or miss for the most part. I'm not 100% sure but I believe the majority, if not all, of TJs that came with 3.73 gears also came with a 44 rear instead of the 35, I'm also fairly certain they all came with the Trac-Lok (limited slip).
As for what to look for in a used axle, leaking seals first and foremost, then how smooth do the bearings feel when you turn the pinion/axles. Looking at the gears for broken, chipped, or heavily warn gears, and if it's a limited slip the clutch packs should make it hard to spin one axle independent from the other by hand. If it has a Trac-Loc and it spins like an open diff the clutches are worn out.
Something to keep in mind when looking at used axles. If there is an axle seal leak the Dana 44 will require bearing replacement, which entails using a press to get the old bearing off and new bearing and seal on.
The Dana 35 is much simpler and the seal and bearing can be replaced independent of each other without the use of a press.
I know this post is a few years old but to suggest those gear recommendations to me is way overkill. With 35’s I’d run 456 or 488 at most. Remember a lot of people including myself use our Jeeps as daily drivers.