just a little question or two

[drivenhardse]

well first off hello to everyone been a day or two since i last posted. looks like missed a bunch of fun. well like tjrubicon say 2000+ miles hard to meat up with you all with out a lot of forward planning.

ok to business does anyone know if the front axle from a early 90's jeep truck them little ones i forget what they call them, will work in my 04 tj? it has a d-44 will need to be regeared to match the rear but it is free and if i can run 37's or 40's it should be worth it.

next can anyone out there tell me what size wheel spacer i will need to run 35-12.5 lt 16's on factory rubi wheels, or is this possible? i got them only 4 but are like bran new for 150 some swampers tsl heck they still got the little nipples on them i dont want to miss out if i can get them to fit.

thanks

[jmbrowning]

ok to business does anyone know if the front axle from a early 90's jeep truck them little ones i forget what they call them, will work in my 04 tj? it has a d-44 will need to be regeared to match the rear but it is free and if i can run 37's or 40's it should be worth it.

If you are referring to the MJ mini-trucks, they used a reverse-cut Dana 30, if memory serves. J-trucks used Dana 44 but they stopped making them in 91.

I would not trust a HP D30 to run 37's or 40's for very long. They probably could go up to 35's with careful application of the skinny pedal and upgraded shafts. Having said that, free is free and the HP D30 probably have better strength and clearance than your current D30. The Missus replaced her front axle with a non-disco HP D30 running 33's and ARB's, no prob. FWIW, she is somewhat GENEROUS with the throttle.

next can anyone out there tell me what size wheel spacer i will need to run 35-12.5 lt 16's on factory rubi wheels, or is this possible?

I measured them at 5.5" backspacing. You will need 1.25" billet spacers or else need to adjust the steering stops. I considered running Moabs but after the price of the billet spacers, it was more cost effective to just sell the 31's/wheels and get steel 15" rims.

[tjrubicon]

are the mj-minni the little cherokee trucks, that is what the axle is coming from and to look at it is for sure beefier than the one in my heep. i am pretty generous also with the throttle i only got a little bitty 2.0 so i got to keep it high in the rpm range to make any power, so 35's would be a little safer? what if i left the front open till i can do a good 44 swap would that help things out so as not to brake anything? i just got back to work so i aint got no savings for the well when it breaks ill fix it idea.

[drivenhardse]

that last post should of been from my name not tj's but oh well share a pc and see what happens right. are there any other options to the billet spacers maybe some steal or another less costly application would anyone havew some used they would like to unload of?

[jmbrowning]

Blatantly lifted from the http://Rubiconownersforum.com newsgroup, but no linking to nonmembers. *shrug*

http://www.rubiconownersforum.com/ph...pic.php?t=2708

Thanks to JerryC Moderator supreme on ROF for this concise treatise on tires and backspacing

What Do I Need to Fit Larger Tires?

Before mounting larger tires to your Rubicon, be aware of the following:
- Installing larger tires will decrease gas mileage and performance due to a decrease in the effective gearing and higher unsprung weight.
- Larger tires will increase braking distance due to increased inertia.
- Larger tires will increase the stress on driveline and suspension components, particularly axles and u-joints.

Wheel Considerations
Before deciding what tires to buy, determine what wheels you want to use. For an explanation of wheel terminology, see the following link on elff's website: http://www.4ezt.com/Vroom/wheel.html

16 Inch Wheels
The stock Moab 16x8 inch wheels will accommodate up to 35 inch tires. A disadvantage to running these wheels is that 16 inch tires are more expensive than the equivalent 15 inch tire. Aftermarket 16 inch wheels are available, although the selection is considerable smaller than 15 inch wheels.

15 Inch Wheels
15 inch 4.5x5 bolt pattern wheels will fit a Rubicon without problems. There are no issues with clearance on the brake rotors or any steering components due to the wheel diameter. There is a huge variety of 15 inch Jeep wheels available from aftermarket suppliers.

Backspacing
Stock Rubicon wheels have 5 inch backspacing. This backspacing creates clearance issues at full steering lock on the front lower control arms when installing larger tires. The interference be corrected by placing a few washers under the steering stops on the front steering knuckle or by installing wheel spacers. Installing washers under the steering stops will result in a loss of turning radius, but the cost is virtually nothing. When aired up, the rears will clear completely in the back. When aired down, even with the washers you will rub the front control arms because the tires will bulge out. In the rear, due to the same reason, you will slightly rub the spring perch. This problem will be compunded if your rear axle is not centered.

If wheel spacers are used, be sure you DO NOT install cast wheel spacers. Only use machined aluminum wheel spacers made by a reputable supplier such as Spidertrax or Mountain Off Road Engineering.

If you are changing wheels, many members have reported wheels with backspacing between 3.5 and 4 inches eliminate interference and provide additional track width without excessive exposure past the edge of the stock flares.

Wheel Materials
For a given wheel size:
- Steel wheels are the least expensive, but are the heaviest.
- Cast aluminum wheels are more expensive than steel, but are lighter. Stock Moab wheels are cast. All cast wheels are easily scratched and gouged on rocks.
- Forged aluminum wheels are the most expensive, but offer the best combination of weight, strength, and scratch resistance.

Choosing Tires (Finally)

33 Inch
Representative Sizes:
285/75R16 and 305/70R16
33x10.50-15 and 33x12.50-15

- Require a minimum of a 2.5 to 3 inch lift to avoid rubbing the fender with the tire fully stuffed. This can be accomplished with a 3 inch suspension lift or combination of smaller lift and body lift. Bumpstops may have to be lengthened.
- Wider flares may be required for tire widths larger than 11.50.
- Your stock speedometer will now read correctly.

35 Inch
Representative Sizes
315/75R16
35x12.50-15

- Require a total of 4 to 4.5 inches of lift to avoid fender rubbing at full stuff. Bumpstop mods are required.
- Wider fender flares probably required.
- A CV driveshaft and adjustable control arms will be required to maintain pinion angles within specs and to avoid driveline vibrations.
- Serious consideration should be given to upgrading axles and u-joints at this level to avoid potential breakage.
- With stock gearing your speedometer will read lower than your actual speed.
- A number of members have changed gears from the stock 4.10 to 4.56 or 4.88 at this point to regain lost performance. Regearing will require the installation of an interface module to correct the speedometer reading.

37 Inch
Representative Sizes
37x12.50-15

- Not for the fainthearted. For the vast majority of owners, this is not a practical choice for a street Jeep.
- Requires a minimum 6 inch lift
- Significant upgrades are required in the driveline and steering to maintain any degree of reliability and drivability.
_________________
The Original Air Rubi
Go ahead, push my buttons...
JerryC
This forum was founded on the idea that it would be a clearinghouse for accurate technical information, based on real world experience, not a bunch of webwheeling speculation and flag_bs.

[drivenhardse]

thanks for the info, this helps i am thinking of going ahead and using the moab wheels since i have them and running the 16 inch 35's since i am getting a heck of a deal, now i will just need to get spacers to solve the clearance troubles i will run into.